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Taking Advantage of the Explosion of Systematic Reviews: An Efficient MEDLINE Search Strategy


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Systematic reviews of the literature are an important resource for clinicians. Unfortunately, the few published strategies for identifying these articles involve MEDLINE interfaces not widely available outside of academic medicine. In addition, the performance of these strategies is unknown. To develop and evaluate a search strategy for identifying systematic reviews by using a publicly available MEDLINE interface (PubMed). Diagnostic test assessment. DEFINITION OF SENSITIVITY: The proportion of recognized systematic reviews (indexed in the Cochrane Library's Database of Abstracts of Reviews of Effectiveness [DARE] or in ACP Journal Club) that are identified by the search strategy. DEFINITION OF POSITIVE PREDICTIVE VALUE: The proportion of articles identified in one of three sample searches (screening for colorectal cancer, thrombolytic therapy for venous thromboembolism, and treatment of dementia) that meet a minimum definition of systematic review. Our PubMed search strategy identified 93 of 100 DARE-indexed systematic reviews, a sensitivity of 93% (95% CI, 86% to 97%). For the sample of systematic reviews drawn from ACP Journal Club (n = 103), the PubMed strategy achieved a sensitivity of 97% (CI, 91% to 99%). When the three sample search strings were used, approximately 50% of retrieved articles met our minimum definition of systematic review. In contrast, the similar precision of a PubMed search restricted to review-type articles (as indexed by MEDLINE) was less than 10%. This search strategy identified most systematic reviews without over-whelming users with numerous false-positive results. A "single-click" filter based on this strategy is now available as part of the Clinical Queries feature of PubMed.
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Taking Advantage of the
Explosion of Systematic
Reviews: An Efficient
MEDLINE Search Strategy
CONTEXT. Systematic reviews of the literature are an important resource for clinicians.
Unfortunately, the few published strategies for identifying these articles involve
MEDLINE interfaces not widely available outside of academic medicine. In addi-
tion, the performance of these strategies is unknown.
OBJECTIVE. To develop and evaluate a search strategy for identifying systematic
reviews by using a publicly available MEDLINE interface (PubMed).
DESIGN. Diagnostic test assessment.
DEFINITION OF SENSITIVITY. The proportion of recognized systematic reviews (indexed
in the Cochrane Library’s Database of Abstracts of Reviews of Effectiveness [DARE]
or in ACP Journal Club) that are identified by the search strategy.
DEFINITION OF POSITIVE PREDICTIVE VALUE. The proportion of articles identified in one
of three sample searches (screening for colorectal cancer, thrombolytic therapy for
venous thromboembolism, and treatment of dementia) that meet a minimum defin-
ition of systematic review.
RESULTS. Our PubMed search strategy identified 93 of 100 DARE-indexed systemat-
ic reviews, a sensitivity of 93% (95% CI, 86% to 97%). For the sample of systematic
reviews drawn from ACP Journal Club (n = 103), the PubMed strategy achieved a
sensitivity of 97% (CI, 91% to 99%). When the three sample search strings were used,
approximately 50% of retrieved articles met our minimum definition of systematic
review. In contrast, the similar precision of a PubMed search restricted to review-
type articles (as indexed by MEDLINE) was less than 10%.
CONCLUSIONS. This search strategy identified most systematic reviews without over-
whelming users with numerous false-positive results. A “single-click” filter based on
this strategy is now available as part of the Clinical Queries feature of PubMed.
iven the limited time available for searching and appraising the medical liter-
ature, systematic reviews are important sources of evidence for clinicians. In
contrast to traditional narrative reviews, systematic reviews of the literature address
a well-defined clinical question, use an explicit strategy to locate relevant evidence,
evaluate the retrieved studies using prospectively defined methodologic criteria, and
formally synthesize the results.
Despite the importance of systematic reviews, MEDLINE does not index these
reviews as a specific publication type.
8, 9
“Review” represents a publication type, but
most of these articles are traditional narrative reviews.
4, 6
“Meta-analysis” also consti-
tutes a publication type; however, not all systematic reviews are meta-analyses, and
not all meta-analyses are indexed by this term.
8, 9
Thus, finding systematic reviews
continues to be a major barrier to their use by clinicians.
© 2001 American College of PhysiciansAmerican Society of Internal Medicine
Department of Medicine
Department of Clinical Pharmacy
Institute for Health Policy Studies
University of California, San
San Francisco, Calif
Eff Clin Pract. 2001;4:157-162.
Edited by Brenda E. Sirovich,
This paper is available at
The few published search strategies for locating
systematic reviews involve versions of MEDLINE not
widely available outside of academic medicine.
8, 9, 11
important, the performance of these strategies has not
been evaluated. In this article, we present a search strate-
gy for identifying systematic reviews that uses PubMed,
a MEDLINE interface freely available via the Internet
from the U.S. National Library of Medicine (NLM).
We assess the sensitivity of this strategy using as a “gold
standard” systematic reviews recognized by two author-
itative sources, and we evaluate the positive predictive
value (or “precision”) obtained by using three sample
clinical searches.
In this article, we use the term systematic review to refer
to any literature review, meta-analysis, guideline, or
other article that explicitly indicates the use of a strategy
for locating evidence. This purposefully broad defini-
tion is not intended to replace published recommenda-
tions for the conduct of systematic reviews.
systematic reviews include other details of the search
strategy and meet additional methodologic criteria for
evidence appraisal and synthesis.
2, 6, 11
Of note, however,
is that fewer than one third of review articles in core
medical journals meet even our broad definition.
MEDLINE is an on-line bibliographic database
created by the NLM that contains more than 11 million
references and abstracts published since 1965.
interfaces are available for searching MEDLINE; each
differs in appearance and internal logic but seeks the
same target content. Although most of these interfaces
are proprietary, the NLM has provided free public
access to MEDLINE through PubMed since 1997.
The PubMed Search Strategy
As with other strategies for locating systematic reviews,
8, 11
the search presented in Table 1 combines relevant publi-
cation types (“meta-analysis,” “review,” “guideline”)
with title and text words typically found in systematic
reviews. The “BUTNOT” phrase in the final search
string eliminates extraneous publication types, such as
letters, editorials, and case reports. The latter common-
ly includes a “review of the literature,” but the thor-
oughness of such literature reviews varies widely.
Moreover, case reports are generally not relevant to
answering questions relating to clinical practice, and
their sheer number can overwhelm clinicians searching
for such answers.
We defined the sensitivity of the search strategy as the
proportion of systematic reviews indexed in two reposi-
tories—the Cochrane Library’s Database of Abstracts of
Reviews of Effectiveness (DARE) or by the American
Effective Clinical Practice July/August 2001 Volume 4 Number 4
A single-line version of the string can be found in the Appendix.
Clicking on “History” on the main search page for the National
Library of Medicine’s PubMed (Figure 1) reveals the number for
each search.
These strings should be typed verbatim in the search window
(Figure 1) or cut and pasted from a text file in which the search
has been stored. Terms in square brackets represent accepted
abbreviations for the search fields targeted by the preceding terms.
“ti” for “title word,” “pt” for “publication type,” and “tw” for
“text word.” One can obtain these abbreviations by displaying any
record in MEDLINE format (one of the options on the Display
pull-down menu in Figure 1) or by clicking on Help/FAQ in the
left column of the main search page (Figure 1). Boolean operators,
such as AND, OR, and BUTNOT, must be written in capital
letters. The asterisk used in search numbers 3, 4, and 6 truncates
the search term so that, for instance, both “guide line” and “guide-
lines” are retrieved.
Searches were performed on May 2, 2001. At that time, limiting
this search string to English-language publications yielded 23,562
PubMed Search for Identifying Systematic
meta-analysis [pt] OR meta-analysis
[tw] OR metanalysis [tw]
Cochrane [tw] OR Medline [tw] OR
CINAHL [tw] OR (National [tw] AND
Library [tw])
(handsearch* [tw] OR search* [tw]
OR searching [tw]) AND (hand [tw]
OR manual [tw] OR electronic [tw]
OR bibliographi* [tw] OR database*
OR #2)
(review [pt] OR guideline [pt] OR
consensus [ti] OR guideline* [ti]
OR literature [ti] OR overview [ti]
OR review [ti]) AND (#2 OR #3)
(synthesis [ti] OR overview [ti] OR
review [ti] OR survey [ti]) AND
(systematic [ti] OR critical [ti] OR
methodologic [ti] OR quantitative
[ti] OR qualitative [ti] OR literature
[ti] OR evidence [ti] OR evidence-
based [ti])
(#1 OR #4 OR #5) BUTNOT (case* [ti]
OR report [ti] OR editorial [pt] OR
comment [pt] OR letter [pt])
College of Physicians–American Society of Internal
Medicine’s ACP Journal Club—that were successfully
retrieved by our search strategy. The DARE contains
quality-assessed systematic reviews identified by regular
searches of important bibliographic databases (such as
MEDLINE) and hand-searching of major journals.
Included reviews must meet at least four methodologic
criteria, and all included articles must display “evidence
of a substantial effort to search for all relevant
The Cochrane Library contains DARE and
lists records (1899 at the time of this evaluation) in an
apparently arbitrary order. We chose as a target sample
the first 100 records that corresponded to articles
indexed in MEDLINE. The total sample required to do
this was 112 (i.e., 12 articles are not in MEDLINE).
Review articles included in ACP Journal Club must
contain “an identifiable description of the methods indi-
cating the sources and methods for searching for articles
and state the clinical topic and the inclusion and exclu-
sion criteria for selecting articles for detailed review.”
In addition, at least one study reviewed in the article
must meet the criteria required of original articles
addressing treatment, diagnosis, prognosis, causation,
quality improvement, or economics of health care pro-
These articles thus represent systematic reviews
that clinicians would wish to retrieve with high sensitiv-
ity. We hand-searched the number of consecutive issues
that was required to identify 100 “reviews” commented
on in ACP Journal Club. Achieving this number
required scanning from the most recent issue at the time
of this search (September/October 2000) back to the first
issue of 1999. This process identified 104 reviews, one of
which was excluded because it represented a Canadian
government report not indexed in MEDLINE.
Positive Predictive Value
We evaluated the positive predictive value of our search
strategy by applying the strategy to each of three clinical
topics: screening for colorectal cancer, thrombolytic thera-
py for venous thromboembolism, and treatment of demen-
tia. The search strings for each clinical topic were created
by using the Medical Subject Headings (MeSH) browser
function, located in the left column of the main search
screen in Figure 1. We then reviewed the titles and
abstracts of each retrieved article to determine whether it
met our criteria for a systematic review.
Effective Clinical Practice July/August 2001 Volume 4 Number 4
FIGURE 1. PubMed home page ( The National Library of Medicine allows unrestricted online
access to MEDLINE through PubMed. PubMed has several useful features. These include the MeSH Browser, which allows users to iden-
tify the optimal Medical Subject Headings relevant to a given clinical topic; Clinical Queries, where a single-click filter based on this strat-
egy is now available; and an option for storing search strings (the Cubby feature).
In the parlance of library science, we measured the
“precision” of the search, which, continuing with the
more familiar terminology of diagnostic tests, corre-
sponds to the positive predictive value—the proportion
of retrieved articles that represent “true positives.” We
regarded an article as a true positive only if the title or
abstract explicitly identified the article as a systematic
review or meta-analysis or if the article abstract indicat-
ed a strategy for locating the literature reviewed. Thus,
an article that contained the phrase “literature review”
in the title but merely stated that “relevant literature was
reviewed” in the abstract would not count as a true pos-
itive. MEDLINE records without an abstract could be
counted as true positives only if the title contained the
words “meta-analysis,” “metaanalysis,” or “systematic
As shown in Table 2, our electronic search strategy
retrieved 93 of the 100 target articles in the DARE (sensi-
tivity, 93% [95% CI, 86% to 97%]). This sensitivity reflects
our exclusion of 12 records not indexed in MEDLINE.
Including such reviews in the target population reduces
the sensitivity to 83% (95% CI, 74% to 89%). Four
the seven DARE articles missed by our electronic search
strategy involve aspects of behavioral medicine likely to
fall outside the interests of most clinicians, reflecting the
broad range of health care fields targeted by DARE.
The reviews drawn from ACP Journal Club, on the
other hand, are explicitly chosen for their relevance to
clinical practice. Among this sample, the electronic search
retrieved 100 of 103 references (Table 2), yielding a sensi-
tivity of 97% (CI, 91% to 99%). Careful review of the
abstracts of the three missed references indicated that fail-
ure to capture one of them
reflected the imperfect sensi-
tivity of the MEDLINE search engine for title words (in
this case, “review”),
21, 20
not the logic of the search strategy.
Positive Predictive Value
As shown in Table 3, approximately 50% of the retrieved
articles met the criteria for true positive in each of the
three sample searches. In other words, half of the articles
retrieved by combining a clinical search string with the
“universe of systematic reviews” created by the general
search (search 6 in Table 1) met our broad definition of
systematic review. For comparison, we measured the
positive predictive value of a search combining one of our
three sample search strings (therapy for dementia) with
the universe of articles referenced by MEDLINE as pub-
lication type “review” in 1999 (not shown in Table 1).
Among the 170 articles retrieved, only 13 met the above
definition for true positive, corresponding to a positive
predictive value of only 8% (CI, 4% to 13%).
The modest positive predictive value for our
search strategy, approximately 50%, is probably an
underestimate, since we required true-positive results to
be identifiable as systematic reviews solely on the basis of
the MEDLINE record. On retrieval of the full-text arti-
cles, some of the retrieved citations not meeting this
requirement (i.e., false positives) proved to be systemat-
ic reviews. For example, while none of the false-positive
articles on colorectal cancer screening met our definition
of a systematic review, three of the five false-positive ref-
erences for thrombolytic therapy for venous thrombo-
explicitly stated that the MEDLINE data-
base was searched,
22, 23, 26
and one of the articles even
provided the search terms used.
We have presented a strategy that allows users to identi-
fy systematic reviews with a sensitivity of more than
90% for articles indexed in MEDLINE. For articles
likely to have the greatest relevance to clinicians (those
indexed in ACP Journal Club), the sensitivity exceeded
95%. This high sensitivity was achieved without many
false-positive results. Approximately 50% of articles
retrieved by sample searches met our broad definition of
systematic review, compared with fewer than 10%
obtained by simply restricting one of the sample search-
es to the publication type “review.”
Some readers might reasonably be concerned
about the broad definition used to evaluate performance
of the search strategy. We chose this approach to impose
a reasonable and easily applicable minimum require-
Effective Clinical Practice July/August 2001 Volume 4 Number 4
*DARE = Cochrane Library’s Database of Abstracts of Reviews
of Effectiveness.
Sensitivity of the Search Strategy*
Number of target
Number of target
articles retrieved
by electronic
Sensitivity (95% CI)
ment for a systematic review, rather than formally
defining attributes required of a high-quality systematic
review. Published recommendations for the method-
ologic features of systematic reviews
1, 2, 6
do not stipulate
the minimum criteria that a review article must fulfill to
count as a systematic review. Above all, we sought to dis-
tinguish between systematic reviews, which tend to
share certain distinctive analytic features, and narrative
reviews, an entirely distinct category. Of the various
methodologic criteria typically applied to systematic
reviews, the explicit mention of a strategy for locating
evidence seemed the most basic and least controversial,
hence our focus on this feature in constructing and eval-
uating our electronic search strategy.
The usefulness of previously published electronic
search strategies for identifying systematic reviews
8, 9, 11
has been limited, since all have used MEDLINE inter-
faces that do not permit free public access (e.g., Ovid).
Moreover, few studies have evaluated the performance of
these strategies. One exception is a study describing a for-
mal search strategy (using the Ovid interface) based on
frequency analysis of terms appearing in a “quasi–gold
standard” sample obtained by hand-searching high-
impact journals.
The proposed strategy achieved 98%
sensitivity while retaining a precision of 20%, but this per-
formance was evaluated against the same gold standard
sample from which the search terms were identified.
We have evaluated an electronic search strategy
that identifies systematic reviews with high sensitivity
without overwhelming users with numerous false-posi-
tive results. Readers are invited to store this search in a
text file for use with subsequent searches (see the
Appendix). While most systematic reviews have
addressed aspects of therapeutics, articles reviewing
diagnosis, prognosis, cause, and even outcomes and
effectiveness research now appear with increasing fre-
Thus, clinicians have at their fingertips a
resource for identifying articles likely to contain evi-
dence-based answers to important clinical questions.
Effective Clinical Practice July/August 2001 Volume 4 Number 4
*To generate the above searches, one would first run the search strategy shown in Table 1 and then type, for instance, “#6 AND
dementia/therapy [mh].” “mh” stands for MESH (Medical Subject Heading) term. The exact results shown above were obtained on
September 20, 2000, with “English language” and “1999/01/01-1999/12/31” used as limits. The 135 specific citations are available
from the authors on request.
Positive Predictive Value of the Search Strategy
Screening for colorectal cancer
Thrombolytic therapy for venous
Treatment of dementia
colorectal neoplasms [mh] AND
(occult blood [mh] OR mass
screening [mh])
(plasminogen activators [mh]
OR thrombolytic therapy [mh])
AND (pulmonary embolism
[mh] OR thromboembolism
[mh] OR venous thrombosis
dementia/therapy [mh]
(95% CI)
Systematic reviews are valuable to clinicians as
unbiased summaries of the state of knowledge of a
specific clinical topic. Unfortunately, they can be
difficult to find.
We developed and tested a search strategy to identify
systematic reviews using PubMed, a freely available
MEDLINE interface.
The strategy retrieved more than 90% of systematic
reviews listed in the Cochrane Library and ACP
Journal Club.
When the articles identified by the strategy were
applied to three selected clinical topics, roughly half
met our criteria for a systematic review.
Clinicians who use this strategy can be confident that
it will provide them with the majority of important
systematic reviews, with a minimum of clutter.
Take-Home Points
1. Oxman AD, Cook DJ, Guyatt GH. Users’ guides to the med-
ical literature. VI. How to use an overview. Evidence-Based
Medicine Working Group. JAMA. 1994;272:1367-71.
2. Oxman AD, Guyatt GH. Guidelines for reading literature
reviews. CMAJ. 1988;138:697-703.
3. Oxman AD. Checklists for review articles. BMJ. 1994;309:648-
4. Cook DJ, Mulrow CD, Haynes RB. Systematic reviews: syn-
thesis of best evidence for clinical decisions. Ann Intern Med.
5. Bero LA, Grilli R, Grimshaw JM, Harvey E, Oxman AD,
Thomson MA. Closing the gap between research and practice:
an overview of systematic reviews of interventions to promote
the implementation of research findings. The Cochrane
Effective Practice and Organization of Care Review Group.
BMJ. 1998;317:465-8.
6. McAlister FA, Clark HD, van Walraven C, et al. The medical
review article revisited: has the science improved? Ann Intern
Med. 1999;131:947-51.
7. Petticrew M. Systematic reviews from astronomy to zoology:
myths and misconceptions. BMJ. 2001;322:98-101.
8. Hunt DL, McKibbon KA. Locating and appraising systemat-
ic reviews. Ann Intern Med. 1997;126:532-8.
9. Glanville J, Lefebvre C. Identifying systematic reviews: key
resources [Editorial]. ACP J Club. 2000;132:A11-2.
10. Bero LA, Jadad AR. How consumers and policymakers can
use systematic reviews for decision making. Ann Intern Med.
11. Jadad AR, Cook DJ, Jones A, et al. Methodology and reports
of systematic reviews and meta-analyses: a comparison of
Cochrane reviews with articles published in paper-based jour-
nals. JAMA. 1998;280:278-80.
12. Lindberg DA. Internet access to the National Library of
Medicine. Eff Clin Pract. 2000;3:256-60.
13. What are the criteria for the inclusion of reviews in DARE?
NHS Centre for Reviews and Dissemination. Available at Accessed 2 May 2001.
14. Purpose and Procedure. ACP Journal Club. Available at Accessed 20
June 2001.
15. Bauman LJ, Drotar D, Leventhal JM, Perrin EC, Pless IB. A
review of psychosocial interventions for children with chronic
health conditions. Pediatrics. 1997;100:244-51.
16. Katon W, Gonzales J. A review of randomized trials of psy-
chiatric consultation-liaison studies in primary care.
Psychosomatics. 1994;35:268-78.
17. Moner SE. Acupuncture and addiction treatment. J Addict
Dis. 1996;15:79-100.
18. Richmond RL. A comparison of measures used to assess effec-
tiveness of the transdermal nicotine patch at 1 year. Addict
Behav. 1997;22:753-7.
19. Magee LA, Ornstein MP, von Dadelszen P. Fortnightly
review: management of hypertension in pregnancy. BMJ.
20. Wilczynski NL, Walker CJ, McKibbon KA, Haynes RB.
Reasons for the loss of sensitivity and specificity of method-
ologic MeSH terms and textwords in MEDLINE. Proc Annu
Symp Comput Appl Med Care. 1995:436-40.
21. Allison JJ, Kiefe CI, Weissman NW, Carter J, Centor RM.
The art and science of searching MEDLINE to answer clini-
cal questions. Finding the right number of articles. Int J
Technol Assess Health Care. 1999;15:281-96.
22. Arcasoy SM, Kreit JW. Thrombolytic therapy of pulmonary
embolism: a comprehensive review of current evidence. Chest.
23. O’Meara JJ 3rd, McNutt RA, Evans AT, Moore SW, Downs
SM. A decision analysis of streptokinase plus heparin as com-
pared with heparin alone for deep-vein thrombosis. N Engl J
Med. 1994;330:1864-9.
24. Jones DR. Audit of attitudes to and use of postoperative
thromboembolic prophylaxis in a regional health authority.
Ann R Coll Surg Engl. 1991;73:219-21; discussion 222.
25. Gallus AS. Anticoagulants in the prevention of venous throm-
boembolism. Baillieres Clin Haematol. 1990;3:651-84.
26. Rogers LQ, Lutcher CL. Streptokinase therapy for deep vein
thrombosis: a comprehensive review of the English literature.
Am J Med. 1990;88:389-95.
27. Boynton J, Glanville J, McDaid D, Lefebvre C. Identifying
systematic reviews in MEDLINE: developing an objective
approach to search strategy design. Journal of Information
Science. 1998;24:137-54.
The authors thank Dr. Brian Haynes for his comments and sug-
gestions on an earlier draft of this manuscript.
Kaveh G. Shojania, MD, Department of Medicine, Box 0120
UCSF, San Francisco, CA 94143-0120; telephone: 415-502-1323;
fax: 415-514-2094; e-mail:
Effective Clinical Practice July/August 2001 Volume 4 Number 4
The search for systematic reviews shown in Table 1 is presented
as a six-line search so that the logic of the search would be
apparent. For everyday use, however, readers are invited to use a
single-line version of this search, which can be copied into a text
file and pasted into PubMed for subsequent searches:
((meta-analysis [pt] OR meta-analysis [tw] OR metanalysis
[tw]) OR ((review [pt] OR guideline [pt] OR consensus [ti] OR
guideline* [ti] OR literature [ti] OR overview [ti] OR review [ti])
AND ((Cochrane [tw] OR Medline [tw] OR CINAHL [tw] OR
(National [tw] AND Library [tw])) OR (handsearch* [tw] OR search*
[tw] OR searching [tw]) AND (hand [tw] OR manual [tw] OR elec-
tronic [tw] OR bibliographi* [tw] OR database* OR (Cochrane [tw]
OR Medline [tw] OR CINAHL [tw] OR (National [tw] AND Library
[tw]))))) OR ((synthesis [ti] OR overview [ti] OR review [ti] OR sur-
vey [ti]) AND (systematic [ti] OR critical [ti] OR methodologic [ti]
OR quantitative [ti] OR qualitative [ti] OR literature [ti] OR evi-
dence [ti] OR evidence-based [ti]))) BUTNOT (case* [ti] OR report
[ti] OR editorial [pt] OR comment [pt] OR letter [pt])
To avoid the inconvenience of transcribing this tortuous
string into a text file, readers can go to the
ecp Web site and
copy the above search string from the full-text version of this arti-
cle (available at Please note: Users of older
version of Netscape should be aware that the search string may
be truncated.
... To identify filters, searchers and researchers use resources such as InterTASC Information Specialists' Sub-Group (ISSG) Search Filter Resource and the McMaster Hedges Team filters [6][7][8][9]. These resources describe different types of filters, some of which are specialized for searching in different databases (e.g., MEDLINE, Embase, CINAHL) and platforms (e.g., Ovid and PubMed) [4,5,[10][11][12][13][14][15][16][17][18]. ...
... The definition of a systematic review used in this study is based on the above and on the PRISMA-P definition [38]: any article that explicitly reports a search strategy to identify studies that meet eligibility criteria and conducts a quantitative or qualitative synthesis of the results. Although this definition does not include a critical appraisal of the evidence, it is more precise than those described in other studies, in which the use of a search strategy was the only criterion for classifying articles as systematic reviews [1,16,20]. ...
... Second, the results will be more precise if the search targets the title field instead of text fields (i.e., title and abstract). Our strategy matches the strategies used by Shojania and Bero [16] and Lunny et al. [10] in that the two terms combined with AND are searched in the title field. ...
Full-text available
Objective: Locating systematic reviews is essential for clinicians and researchers when creating or updating reviews and for decision-making in health care. This study aimed to develop a search filter for retrieving systematic reviews that improves upon the performance of the PubMed systematic review search filter. Methods: Search terms were identified from abstracts of reviews published in Cochrane Database of Systematic Reviews and the titles of articles indexed as systematic reviews in PubMed. Both the precision of the candidate terms and the number of systematic reviews retrieved from PubMed were evaluated after excluding the subset of articles retrieved by the PubMed systematic review filter. Terms that achieved a precision greater than 70% and relevant publication types indexed with MeSH terms were included in the filter search strategy. Results: The search strategy used in our filter added specific terms not included in PubMed's systematic review filter and achieved a 61.3% increase in the number of retrieved articles that are potential systematic reviews. Moreover, it achieved an average precision that is likely greater than 80%. Conclusions: The developed search filter will enable users to identify more systematic reviews from PubMed than the PubMed systematic review filter with high precision.
... The PT committees or commissions are aimed at contributing to optimize the quality of healthcare in the population through the cost-effective use of medicines, when necessary. 13,14 Objectives • Develop, implement, and keep an updated formulary system, including an Essential Medicines List (EML), a National Therapeutic Formulary (NTF) and ...
... It is the responsibility of each country to determine which specific medicines and other HTs are considered essential. 14 The EML and the List of Priority Medical Devices for the first level of care of the countries require regular review in order to update their content according to variations in health needs and/or the potential emergence of innovative medicines or other HTs in the pharmaceutical market, which offer additional therapeutic benefits to the population (increased effectiveness and/or lower risk). This is valid for any intended health setting. ...
... Specifically, for each studied group, report the number of participants randomly assigned, those who have received the intended treatment, those who have completed the study protocol and those analyzed for the primary outcome. Description of study protocol deviations, together with the reasons for those deviations Recruiting 14 Dates defining recruitment and follow-up periods Baseline data 15 Demographic and clinical characteristics of each group Numbers analyzed 16 The number of participants (denominator) from each group included in each analysis, and specifying whether the analysis has been conducted by "intention to treat". Indicate results in absolute numbers when possible (e.g., 10/20, instead of 50%) Results and estimate 17 For each primary and secondary endpoint, a summary of results for each group and the estimate size of the effect and its precision (e.g., 95% confidence interval) Auxiliary analysis 18 Report any other analysis conducted, including subgroup and adjusted analysis, indicating those that have been pre-specified and those that are exploratory Adverse effects 19 All the relevant adverse events or secondary effects in each intervention group DISCUSSION Interpretation 20 ...
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This Manual is dedicated to Prof. Dr. Héctor Omar Buschiazzo, restless fighter for access to health as a human right in the entire region of the Americas and tireless advocate for the operation of pharmacotherapy committees in every hospital. Mentor, example, husband and friend. Medicines are one of the available strategies to optimize the quality of healthcare. Their (local or imported) procurement, production, distribution, storage, dispensation and adequate use in the patient are the links of a management chain that contributes positively and significantly to improve the quality of healthcare. It is important to remember that if the available and necessary medicines cannot be obtained, other considerations about their use are rendered invalid. Therefore, accessibility is an important aspect to bear in mind. A medicine may be safe, effective and of good quality, but it loses all these attributes if it is not accessible. When they are needed, medicines contribute to the recovery and rehabilitation of health, representing a valuable tool in medical practice, as long as they are used rationally. Rational Use of Medicines is defined as: “the application of the set of knowledge endorsed by science and evidence, based on quality, efficacy, efficiency and safety, that allow selecting, prescribing, dispensing and using a particular medicine in the precise moment and for the adequate health condition, with the active participation of the patient facilitating treatment adherence and follow-up”. This definition includes the entire process related to the act of prescribing, since there is a set of actions that requires scientific knowledge, in order to select the best medicine for the appropriate clinical condition of each patient, and where the patient becomes actively involved in his relationship with the physician and his health condition.
... In den Gesundheitswissenschaften wird die Zahl der SRs und MAs unterschätzt, da bis vor kurzem von vielen Forschern Schwierigkeiten bei ihrer Lokalisierung beklagt wurden [Hunt, 1997;Shojania, 2001]. Anhand der Handsuchen von 161 [Montori, 2005a] bzw. ...
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Heterogeneity in meta-analysis can be caused by chance, methodological or clinical variations between the included primary studies. To identify a clinical variable as a cause of heterogeneity in meta-analysis, one should firstly investigate chance and methodological variations. Meta-analysis with individual patient data (MA-IPD) has a greater potential than that with aggregate patient data (MA-APD) to detect which subgroups of patients get less, more or no benefit from an intervention. In this thesis two systematic reviews and a MA-APD were undertaken. The first review searched systematically for empirical studies on the impact of bias in randomised controlled trials (RCTs) on the results of meta-analysis. 39 studies were identified and 134 empirical comparisons between trials of high and low methodological quality could be extracted and summarized using a random effects model. RCTs with low quality scores, with inadequate method of randomisation, with inadequate concealment of allocation and those without any type of blinding, on average, overestimated the treatment efficacy. However, most of the empirical studies did not consider clinical causes of heterogeneity. This fact may confound the relation between methodological quality and effect size. Simultaneous investigation of diverse sources of heterogeneity is required. The second review searched systematically for empirical comparisons between MA-IPD and MA-APD. 70 comparisons were extracted from 25 empirical studies. Two thirds of the comparisons showed a tendency to overestimate the effect size and to reduce its precision by MA-APD in comparison to MA-IPD. However, the differences between the point estimates of both types of meta-analysis were small in all comparisons but one, and the paired t-test found no significant difference between the two types of meta-analysis. Furthermore, only half of the studies reported the results of a heterogeneity test. The methodological quality of RCTs was assessed in both types of meta-analysis only in a quarter of the studies. Clinical heterogeneity was investigated only in one third of the studies, using both types of meta-analysis, with no consistent results. A published MA-IPD on the efficacy of statins was reanalysed using aggregate patient data. The summary effect sizes of all cause mortality in both meta-analyses were extremely similar. Although the Cochran test of heterogeneity was significant, this was neither reported nor taken into account in MA-IPD. MA-APD combined the RCTs using a random effects model. The methodological variations between the RCTs were not assessed in MA-IPD. MA-APD investigated possible methodological and clinical causes of variation between the RCTs. These were determined a priori and justified with external evidence. Subgroup analysis and meta-regression were used to explore the relation between the selected causes of heterogeneity and mortality. By using a multivariate regression model that included terms for the methodological quality and baseline low-density lipoprotein a significant negative relationship between the inclusion of women in RCTs and the extent of reduction in mortality was detected. This result suggests a lower efficacy of statins in women which deserves further investigation in future RCTs. It can be concluded that the investigation of various sources of heterogeneity in meta-analysis of RCTs is still rare. Careful exploration of chance and methodological variations should precede the investigation of clinical heterogeneity and confounding between the sources of heterogeneity should be taken into consideration. III Inhaltsverzeichnis Seite Abstract II Inhaltsverzeichnis III Abkürzungsverzeichnis IX Tabellenverzeichnis X Abbildungsverzeichnis XI Einleitung 1
... The electronic search will be conducted in English by the first author and will not use any restrictions regarding language or time frame. We will use an incorporated and validated filter in MEDLINE to identify systematic reviews [29]. A summary of the electronic search in MEDLINE is shown in Table 1. ...
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Background: Chronic obstructive pulmonary disease (COPD) is a common chronic disease that can be treated and monitored with various digital technologies. Digital technologies offer unique opportunities for treating and monitoring people with chronic diseases, but little is known about whether the outcomes of such technologies depend on sex, gender, or age in people with COPD. Objective: The general objective of this study is to assess the possible influence of sex, gender, or age on outcomes of digital technologies for treatment and monitoring of COPD through an overview of systematic reviews. Methods: The study is planned as an overview of systematic reviews. Study reporting is based on the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) 2020 guidelines because guidelines for overviews are not available as of this writing. The information sources for the overview will include 4 bibliographic databases (MEDLINE, Cochrane Library, Epistemonikos, and Web of Science) as well as the bibliographies of the included systematic reviews. The electronic search strategy will be developed and conducted in collaboration with an experienced database specialist. The search results will be presented in accordance with the PRISMA 2020 guidelines. The eligibility of studies is based on the population, intervention, comparison, outcomes, and study design (PICOS) criteria: (1) people with COPD (population), (2) digital technology intervention for treatment or monitoring (intervention), (3) any control group or no control group (comparison), (4) any outcome, and (5) systematic review of randomized controlled trials or non-randomized controlled trials with or without a meta-analysis (study design). Critical appraisal of the included systematic reviews will be performed using A Measurement Tool to Assess Systematic Reviews, version 2 (AMSTAR 2). Data will be extracted using a standardized data extraction sheet. Results: The literature search is scheduled for June 2022. We expect to select the relevant systematic reviews, code the data, and appraise the systematic reviews by December 2022. Conclusions: There is a growing recognition that the influence of sex, gender, or age should be considered in research design and outcome reporting in the context of health care interventions. Our overview will identify systematic reviews of various digital technologies for treatment or monitoring of COPD. The most interesting aspect of the overview will be to investigate if any systematic reviews considered the influence of sex, gender, or age on the outcomes of such digital technologies in COPD. Evidence from the overview could be used to guide more individualized (sex, gender, or age-based) recommendations for the use of digital technologies among people with COPD. Trial registration: PROSPERO International Prospective Register of Systematic Reviews CRD42022322924;
... La literatura se buscará en las bases de datos Medline (vía Pubmed), Embase, Colaboración Cochrane y LILACS (vía BVS). Para este fin se diseñarán estrategias que incluyan términos controlados según la base y otros términos correspondientes a los temas seleccionados (tabla 1) (15,16). Adicionalmente, se llevará a cabo una búsqueda secundaria con una estrategia de bola de nieve con las referencias citadas en los manuscritos. ...
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Introduction: Coffee is a drink that is associated with metabolic changes, including changes in the lipid profile. On the other hand, lipid alterations, such as increased LDL cholesterol or decreased HDL cholesterol, are associated with adverse cardiovascular outcomes. Taking into account the frequency of consumption of this drink and the recent evidence regarding its impact on cardiovascular system and deaths, it is necessary to review the recent evidence to understand how coffee consumption modifies the lipid profile. Methods and analysis: We will search Embase, Pubmed, BVS and Cochrane from inception to March 2021 with language restriction to French, Spanish and English. We will include meta-analyses and systematic reviews that evaluate the impact of coffee consumption on the lipid profile in adults. Methodological quality of each study will be evaluated using the Assessment of Multiple Systematic Reviews 2 (Amstar2) tool. The heterogeneity of the results reported using the I2 estimator will be taken into account. A sensitivity analysis of the results will be carried out by subgroups according to the quality of the included studies.
... the PubMed literature search was done with the Abstract Sifter tool (Baker, Knudsen, and Williams, 2017); filtering for duplicates with Sciome SWIFT-Review and SWIFT Active Screener; screening and selection with SWIFT Active Screener; extraction, coding, bibliographic information and data storage in Microsoft Excel. The PubMed SR search strategy uses the systematic review filter from (Shojania and Bero, 2001): (Embryonic stem cells OR IPSC OR Induced Pluripotent Stem Cells OR embryonal stem cells OR "embryonic stem cell"[tw]) AND ((toxicity OR congenital abnormalities OR prenatal exposure delayed effects OR dysmorphogenesis OR dysmorphogenetic OR abnormalities, drug-induced) AND (fetus OR embryo OR embryonic OR embryonic development OR larva OR eggs OR prenatal OR pregnancy OR Gene Expression Regulation, Developmental) AND ((chemical OR drug OR compound OR toxicity tests OR High-Throughput Screening Assays) OR embryotoxicity OR embryotoxicants OR teratogenicity OR teratogens OR developmental toxicity OR developmental toxicants OR teratogenic agents OR "developmental neurotoxicity" OR "developmental cardiotoxicity")). The queries used and the resulting filtered and screened publication lists can be found (and the queries rerun) in the Abstract Sifter included as Supplemental File S1. ...
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This manuscript provides a review focused on embryonic stem cell-based models and their place within the landscape of alternative developmental toxicity assays. Against the background of the principles of developmental toxicology, the wide diversity of alternative methods using pluripotent stem cells developed in this area over the past half century is reviewed. In order to provide an overview of available models, a systematic scoping review was conducted following a published protocol with inclusion criteria, which were applied to select the assays. Critical aspects including biological domain, readout endpoint, availability of standardized protocols, chemical domain, reproducibility and predictive power of each assay are described in detail, in order to review the applicability and limitations of the platform in general and progress moving forward to implementation. The horizon of innovative routes of promoting regulatory implementation of alternative methods is scanned, and recommendations for further work are given.
... A combination of keywords that reflect CMs and polio eradication and routine immunization was employed in the searches. The terms for the systematic search were adaptations from the validated filters for online version of Index Medicus produced by the United States' Library of Medicine (PubMed) (Shojania and Bero) [20] and an Elsevier database of research articles and related works (EMBASE) (Wilczynski and Haynes) [21] and were parallel-reviewed again by another expert. Duplicates were identified and removed from the list of retrieved articles before conducting title and abstract screening on a spreadsheet. ...
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Community mobilization, partnership, and surveillance are regarded as key elements in various polio eradication activities. Several nongovernmental organizations have led community mobilizers (CMs) in different aspects of the polio eradication campaigns, and their effectiveness shows mixed findings. This study systematically reviewed the literature on the role of CMs in polio eradication activities. Literature searches were conducted using a combination of key words to find relevant published studies up to 30 November 2020. The 27-item Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist addressing the various components of systematic review was adhered to. A total of 1627 articles were identified by the search, with 65 articles passing the title/abstract and full text reviews, and with four additional articles obtained from references of articles included (making a total of 69 articles). Of these 69 articles involved in the review, 24 (five reviews and 19 original articles) focused largely and explicitly on CMs and were included in the full review. The rest (45) discussed CMs in a broader context, hence they were summarized based on part 1 of the data extraction form only. The findings of the review indicated that although CMs’ instrumental role in health promotion and supporting immunization is consistent for all the reviewed studies, their role in acute flaccid paralysis (AFP) case detection is limited. The role of CMs, other actors in community-based surveillance, and health education needs to be further strengthened, particularly in high-risk communities where routine immunization and AFP surveillance are much needed. Keywords: Acute flaccid paralysis, community mobilization, community mobilizers, polio and systematic review
Background: Musculoskeletal conditions are the leading contributor to global healthcare expenditure and with an increase in ageing global population, this number is projected to rise further. Objectives: To determine the top 100 most-cited studies in field of musculoskeletal rehabilitation and to conduct their bibliometric analysis. Design: Scopus was used for identification of studies, published in the field of musculoskeletal rehabilitation over last five decades. Methods: Literature search was conducted in February 2021 with final Boolean search phrases being: [(musculoskeletal) and (rehabilitation) and (musculoskeletal rehabilitation)]. In addition to number of citations, data was also collected for other variables such as title of study, topic of discussion, subdivisions of clinical and applied science involved in conduction of study, study design, journal and its impact factor, year of publication, and country where study was conducted. Results: The top 100 most-cited articles in musculoskeletal rehabilitation over the last 50 years were published between 1973 and 2015. Total number of citations was 24,366, with an average of 243.66 citations per paper. Highest citation was reported by a paper on treatment of low back pain by Waddell G. The decade of 2000-2009 contributed maximum articles with highest number of publications from journal "Archives of Physical Medicine and Rehabilitation". Most of the publications were from United States and most common topic to feature among these articles was "Strength training". Conclusions: This study identifies the top 100 most-cited articles in musculoskeletal rehabilitation and provides insight into its historical trends while serving as a guide for future research.
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Background A condition is defined as rare if it affects fewer than 1 in 2000 people in the general population. Limited evidence suggests that care is poorly co-ordinated for people affected by rare conditions. Objectives To investigate if and how care of people with rare conditions is co-ordinated in the UK, and how people affected by rare conditions would like care to be co-ordinated. Design A mixed-methods study comprising (1) a scoping review to develop a definition of co-ordinated care and identify components of co-ordinated care ( n = 154 studies); (2) an exploratory qualitative interview study to understand the impact of a lack of co-ordinated care ( n = 15 participants); (3) a national survey among people affected by rare conditions of experiences of care co-ordination ( n = 1457 participants); (4) a discrete choice experiment of preferences for co-ordination ( n = 996 participants); (5) the development of a taxonomy of co-ordinated care for rare conditions ( n = 79 participants); and (6) a review of costs of providing co-ordinated care. Setting Health services for people affected by rare conditions, including gatekeeping to social care provision and third-sector care. Participants Adult patients with rare conditions, parents/carers of children or adults with rare conditions and health-care professionals (e.g. doctors, nurses and allied health professionals) involved in the care of people with rare conditions. No limits were set on the rare conditions included or where people live in the UK. Participants were sampled from patient and provider networks and organisations. Results A definition of co-ordinated care for rare conditions was developed. Care for people affected by rare diseases was found to be not well co-ordinated. For example, only 12% of 760 adult patients affected by a rare disease reported that they had a formal care co-ordinator, 32% reported that they attended a specialist centre and 10% reported that they had a care plan. Patients, parents/carers and health-care professionals all would like care to be better co-ordinated, with some differences in preferences reported by patients and parents/carers and those reported by health-care professionals. Our taxonomy of care co-ordination for rare conditions outlined six domains: (1) ways of organising care, (2) ways of organising teams, (3) responsibilities, (4) how often care appointments and co-ordination take place, (5) access to records and (6) mode of communication. Limitations It was not possible to capture the experiences of people affected by every rare condition. Our sampling strategy in the study may have been biased if study participants were systematically different from the population affected by rare conditions. The cost analysis was limited. Conclusions There is evidence of a lack of co-ordinated care for people affected by rare diseases. This can have a negative impact on the physical and mental health of patients and families, and their financial well-being. Future work Further research would be beneficial to develop feasible, clinically effective and cost-effective models of care co-ordination, using the taxonomy developed in this study. Study registration This study is registered as NIHR Clinical Research Network Portfolio reference number 41132, Research Registry reference number research registry6351 and Integrated Research Application System reference number 254400. Funding This project was funded by the National Institute for Health Research (NIHR) Health and Social Care Delivery Research programme and will be published in full in Health and Social Care Delivery Research ; Vol. 10, No. 5. See the NIHR Journals Library website for further project information.
PubMed is a free web-based public access resource that supports the search and retrieval of literature from the National Library of Medicine’s MEDLINE database. In the past 2 years, PubMed has been updated to improve functionality and add important new features,¹⁻³ including a set of search statements to identify COVID-19 articles and a new publication filter to allow PubMed searches to retrieve early-release preprints.⁴,5 This Viewpoint describes how these important new PubMed features and functions could allow clinicians to use a 3-step literature searching process to obtain real-time answers to important clinical questions. A brief example of this 3-step process is in the Supplement.
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The current medical environment makes information retrieval a matter of practical importance for clinicians. Many avenues present themselves to the clinician, but here we focus on MEDLINE by summarizing the current state of the art and providing an innovative approach for skill enhancement. Because new search engines appear rapidly, we focus on generic principles that can be easily adapted to various systems, even those not yet available. We propose an idealized classification system for the results of a MEDLINE search. Type A searches produce a few articles of high quality that are directly focused on the immediate question. Type B searches yield a large number of articles, some more relevant than others. Type C searches produce few or no articles, and those that are located are not germane. Providing that relevant, high-quality articles do exist, type B and C searches may often be improved with attention to search technique. Problems stem from poor recall and poor precision. The most daunting task lies in achieving the balance between too few and too many articles. By providing a theoretical framework and several practical examples, we prepare the searcher to overcome the following barriers: a) failure to begin with a well-built question; b) failure to use the Medical Subject Headings; c) failure to leverage the relationship between recall and precision; and d) failure to apply proper limits to the search. Thought and practice will increase the utility and enjoyment of searching MEDLINE.
Preparing a review entails many judgments. The focus of the review must be decided. Studies that are relevant to the focus of the review must be identified, selected for inclusion and critically appraised. Information must be collected and synthesised from the relevant studies, and conclusions must be drawn. Checklists can help prevent important errors in this process. Reviewers, editors, content experts, and users of reviews all have a role to play in improving the quality of published reviews and promoting the appropriate use of reviews by decisionmakers. It is essential that both providers and users appraise the validity of review articles.
Preparing a review entails many judgments. The focus of the review must be decided. Studies that are relevant to the focus of the review must be identified, selected for inclusion and critically appraised. Information must be collected and synthesised from the relevant studies, and conclusions must be drawn. Checklists can help prevent important errors in this process. Reviewers, editors, content experts, and users of reviews all have a role to play in improving the quality of published reviews and promoting the appropriate use of reviews by decisionmakers. It is essential that both providers and users appraise the validity of review articles. Why checklists? When we think about flying, it is obvious why a checklist is used before take off. Airplanes are complex machines. Things can go wrong with them, and it is preferable that problems are discovered on the ground. However brilliant a pilot and crew might be, most of us would prefer that they use a checklist when preparing for take off, rather than relying on memory. The need for checklists for review articles is less obvious, but the rationale is much the same. Preparing a review is a complex process entailing many judgements. The focus of the review must be decided. Studies that are relevant to the focus of the review must be identified, selected for inclusion, and critically appraised. Information must be collected and synthesised from the relevant studies, and conclusions must be drawn. Many decisions must be made throughout this process. It is important to go through this process systematically to avoid errors. Explicitness about how decisions were made enables others to assess how well the process protected against errors. Checklists can help those doing and using reviews to avoid important errors. Faulty reviews may not seem as perilous as faulty airplanes. However, if people are going to …
Background: systematic reviews are of increasing importance to health care professionals seeking to provide evidence-based health care, because they provide systematically prepared summaries of the current state of research knowledge on the effectiveness of health care interventions. To be able to make use of them, both researchers preparing systematic reviews and health care professionals need to be able to identify systematic reviews easily. In the past, systematic reviews have been difficult to identify easily among the mass of literature labelled ‘reviews’. Search strategies have been published which were intended to provide easier access to systematic reviews and meta-analyses. These strategies, mostly devised for the MEDLINE database, have been constructed using the authors’ knowledge of the subject area, the databases and past experience. Objective: the objective of this study was to design search strategies based on a more objective approach to strategy construction. Methods: word frequencies from the titles, abstracts and subject keywords of a collection of systematic reviews of the effective health care interventions were analysed to derive a highly sensitive search strategy. Results: the proposed strategy offers 98% sensitivity in retrieving systematic reviews, while retaining a low but acceptable level of precision (20%). Other strategies with other levels of sensitivity and precision are also presented. Discussion: this study shows that a frequency analysis approach can be used to generate highly sensitive strategies which retain adequate levels of precision when retrieving systematic reviews.
This study examines outcome measures of abstinence among studies reporting 12-month outcomes of the nicotine transdermal patch using different measures of effectiveness. This was achieved by reviewing published randomized controlled studies reporting 1-year abstinence rates of the nicotine transdermal patch. Comparisons are made across studies of three outcome measures used to report abstinence: point prevalence, continuous, and prolonged abstinence. Studies that measured outcome in terms of continuous and prolonged abstinence at 1 year showed double the effect for the active patch compared to placebo; however, this difference was not always apparent in those studies using point prevalence as the outcome measure.
The validity of a review depends on its methodologic quality. To determine the methodologic quality of recently published review articles. Critical appraisal. All reviews of clinical topics published in six general medical journals in 1996. Explicit criteria that have been published and validated were used. Of 158 review articles, only 2 satisfied all 10 methodologic criteria (median number of criteria satisfied, 1). Less than a quarter of the articles described how evidence was identified, evaluated, or integrated; 34% addressed a focused clinical question; and 39% identified gaps in existing knowledge. Of the 111 reviews that made treatment recommendations, 48% provided an estimate of the magnitude of potential benefits (and 34%, the potential adverse effects) of the treatment options, 45% cited randomized clinical trials to support their recommendations, and only 6% made any reference to costs. The methodologic quality of clinical review articles is highly variable, and many of these articles do not specify systematic methods.
A survey of usage and attitudes to thromboembolic prophylaxis among 46 general surgeons in the Mersey Region found that 87% use either low-dose heparin, graduated compression stockings or both on a regular basis for their major cases. However, there was a wide variation of usage: 9 (19.6%) always used heparin in combination with thromboembolic stockings, 4 (8.7%) always used heparin alone, no surgeon used thromboembolic stockings alone. A total of 18 (39%) used thromboembolic stockings in combination with heparin, one-half of them selectively. A further 24% of surgeons used either low-dose heparin or thromboembolic stockings or both on selected patients. Current literature beliefs concerning the efficacy of low-dose heparin and thromboembolic stockings showed a similar variation, with 13% of surgeons believing that the efficacy of low-dose heparin against postoperative deep vein thrombosis has not been shown, 22% believing that thromboembolic stockings were ineffective against postoperative deep vein thrombosis, and 24% believing that low-dose heparin was of no value as a prophylactic agent against postoperative pulmonary embolism. Published meta-analysis has shown these beliefs to be wrong.
For 50 years, the key to successfully preventing venous thrombosis (VT) or pulmonary embolism (PE) among high-risk patients has been the judicious use of anticoagulants: first through full doses of oral anticoagulants and more recently through low-dose heparin prophylaxis. Low-dose heparin has become the standard of comparison for other preventive methods, since it is relatively safe and simple, its ability to prevent approximately 65% of the subclinical VT found by leg scanning after elective general surgery is well known, and recent meta-analysis of the many pertinent published clinical trials (large and small) strongly suggests a much greater benefit: a 65% reduction in the risk of postoperative death from major PE. In addition, there are trials that have also found low-dose heparin to be effective in general medical patients, although its value in this clinical setting is much less well documented. Although several effective approaches other than low-dose heparin are available, many of these tend to be either more cumbersome (intermittent external leg compression) or probably less powerful (graded pressure elastic stockings). There are situations where low-dose heparin prophylaxis fails, most obviously after orthopaedic surgery where the use of more complex regimens, including adjusted-dose heparin treatment and various schedules of warfarin prophylaxis, becomes appropriate. Recent progress has come from the intensive clinical exploration of various low molecular weight heparin fractions or fragments which appear to be effective after once daily administration to general surgical patients and show great promise of effectiveness and safety after hip surgery. The level of warfarin effect needed for VT prophylaxis has also been reinvestigated, with trials suggesting a need for less warfarin and a lower prothrombin time effect than was previously thought to be appropriate. Given that any attempts to minimize mortality from PE in hospital patients must rely on the widespread and systematic use of simple, safe, and cost-effective preventive methods, it is hoped that these advances will help move anticoagulant prophylaxis further out of the realm of clinical research and into that of common clinical practice.
A comprehensive review of the English literature evaluating streptokinase (SK) in the treatment of deep venous thrombosis (DVT) of the lower extremity reveals complete lysis of thrombi in as many as 70% of patients studied. The degree of lysis is affected by duration of symptoms before treatment, degree of occlusion, thrombus location, and development of a plasma proteolytic state. SK-treated patients have not been found to have a greater incidence of major hemorrhagic complications when compared with heparin-treated patients. SK is clearly beneficial in the treatment of DVT if patients are properly selected and carefully managed. Proper patient selection and a recommended treatment protocol are described.
One strategy for dealing with the burgeoning medical literature is to rely on reviews of the literature. Although this strategy is efficient, readers may be misled if the review does not meet scientific standards. Therefore, guidelines that will help readers assess the scientific quality of the review are proposed. The guidelines focus on the definition of the question, the comprehensiveness of the search strategy, the methods of choosing and assessing the primary studies, and the methods of combining the results and reaching appropriate conclusions. Application of the guidelines will allow clinicians to spend their valuable reading time on high-quality material and to judge the validity of an author's conclusions.