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n engl j med 355;26 www.nejm.org december 28, 2006
2725
The new england
journal of medicine
established in 1812
december 28, 2006
vol. 355 no. 26
An Intervention to Decrease Catheter-Related Bloodstream
Infections in the ICU
Peter Pronovost, M.D., Ph.D., Dale Needham, M.D., Ph.D., Sean Berenholtz, M.D., David Sinopoli, M.P.H., M.B.A.,
Haitao Chu, M.D., Ph.D., Sara Cosgrove, M.D., Bryan Sexton, Ph.D., Robert Hyzy, M.D., Robert Welsh, M.D.,
Gary Roth, M.D., Joseph Bander, M.D., John Kepros, M.D., and Christine Goeschel, R.N., M.P.A.
A b s t r ac t
From the School of Medicine (P.P., D.N.,
S.B., S.C., B.S.), the School of Professional
Studies in Business and Education (D.S.),
and the Bloomberg School of Public Health
(H.C.), Johns Hopkins University, Balti-
more; and the University of Michigan,
Ann Arbor (R.H.); William Beaumont Hos-
pital, Royal Oak (R.W.); Ingham Regional
Medical Center, Lansing (G.R.); Harper
University Hospital, Detroit (J.B.); Sparrow
Health System, Lansing (J.K.); and the
Michigan Health and Hospital Association
Keystone Center for Patient Safety and
Quality, Lansing (C.G.) — all in Michigan.
N Engl J Med 2006;355:2725-32.
Copyright © 2006 Massachusetts Medical Society.
Background
Catheter-related bloodstream infections occurring in the intensive care unit (ICU)
are common, costly, and potentially lethal.
Methods
We conducted a collaborative cohort study predominantly in ICUs in Michigan. An
evidence-based intervention was used to reduce the incidence of catheter-related
bloodstream infections. Multilevel Poisson regression modeling was used to com-
pare infection rates before, during, and up to 18 months after implementation of
the study intervention. Rates of infection per 1000 catheter-days were measured at
3-month intervals, according to the guidelines of the National Nosocomial Infections
Surveillance System.
Results
A total of 108 ICUs agreed to participate in the study, and 103 reported data. The
analysis included 1981 ICU-months of data and 375,757 catheter-days. The median
rate of catheter-related bloodstream infection per 1000 catheter-days decreased
from 2.7 infections at baseline to 0 at 3 months after implementation of the study
intervention (P≤0.002), and the mean rate per 1000 catheter-days decreased from
7.7 at baseline to 1.4 at 16 to 18 months of follow-up (P<0.002). The regression model
showed a significant decrease in infection rates from baseline, with incidence-rate
ratios continuously decreasing from 0.62 (95% confidence interval [CI], 0.47 to 0.81)
at 0 to 3 months after implementation of the intervention to 0.34 (95% CI, 0.23 to
0.50) at 16 to 18 months.
Conclusions
An evidence-based intervention resulted in a large and sustained reduction (up to 66%)
in rates of catheter-related bloodstream infection that was maintained throughout
the 18-month study period.
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C
atheter-related bloodstream in-
fections are common, costly, and potential-
ly lethal.
1,2
Each year in the United States,
central venous catheters may cause an estimated
80,000 catheter-related bloodstream infections
and, as a result, up to 28,000 deaths among pa-
tients in intensive care units (ICUs). Given that the
average cost of care for a patient with this infec-
tion is $45,000,
3
such infections could cost up to
$2.3 billion annually. According to the National
Nosocomial Infections Surveillance (NNIS) sys-
tem of the Centers for Disease Control and Pre-
vention (CDC), the median rate of catheter-related
bloodstream infection in ICUs of all types ranges
from 1.8 to 5.2 per 1000 catheter-days.
3,4
Interven-
tions aimed at decreasing the infection rate are
needed to reduce the serious public health conse-
quences of this hospital-acquired infection.
How many of these infections are preventable
is unknown. Several single-hospital studies and
two multicenter studies have shown reductions in
the rates of catheter-related bloodstream infec-
tion.
5-12
To build on this research, we studied the
extent to which these infections could be reduced
in Michigan, using an intervention as part of a
statewide safety initiative regarding patients in
ICUs, known as the Michigan Health and Hospi-
tal Association (MHA) Keystone Center for Patient
Safety and Quality Keystone ICU project, which
was funded predominantly by the Agency for
Healthcare Research and Quality (AHRQ). The
objective of the study was to evaluate the effect
of the intervention up to 18 months after its im-
plementation.
M e t hod s
The Intervention
All Michigan hospitals with ICUs for adults were
invited to participate in the Keystone ICU project,
launched in October 2003. Hospitals were not
asked to provide reasons for not participating. Five
out-of-state hospitals of a health system with its
corporate headquarters in Michigan participated
at the request of the senior executive of the health
system. Between March 2004 and September 2005,
each ICU implemented several patient-safety inter-
ventions, according to a prospective cohort study
design, and monitored the effect of these inter-
ventions on specific safety measures.
In addition to the intervention to reduce the
rate of catheter-related bloodstream infection, the
ICUs implemented the use of a daily goals sheet
to improve clinician-to-clinician communication
within the ICU,
13
an intervention to reduce the
incidence of ventilator-associated pneumonia,
14
and a comprehensive unit-based safety program
to improve the safety culture.
15,16
The period nec-
essary for implementation of each intervention
was estimated to be 3 months. Hospitals started
with implementation of the unit-based safety pro-
gram and use of the daily goals sheet and then,
in any order, implemented the other two interven-
tions during the subsequent 6 months.
Before implementing any of the components
of the study intervention, the ICUs were asked to
designate at least one physician and one nurse as
team leaders.
17
The team leaders were instructed
in the science of safety and in the interventions
and then disseminated this information among
their colleagues. Training of the team leaders
was accomplished through conference calls every
other week, coaching by research staff, and state-
wide meetings twice a year. The teams received
supporting information on the efficacy of each
component of the intervention, suggestions for
implementing it, and instruction in methods of
data collection (described in detail in Appendix A
of the Supplementary Appendix, available with
the full text of this article at www.nejm.org). Team
leaders were partnered with their local hospital-
based infection-control practitioners to assist in
the implementation of the intervention and to
obtain data on catheter-related bloodstream in-
fections at the hospital.
The study intervention targeted clinicians’ use
of five evidence-based procedures recommended
by the CDC and identified as having the greatest
effect on the rate of catheter-related bloodstream
infection and the lowest barriers to implementa-
tion.
1
The recommended procedures are hand
washing, using full-barrier precautions during the
insertion of central venous catheters, cleaning the
skin with chlorhexidine, avoiding the femoral site
if possible, and removing unnecessary catheters.
Strategies to increase the use of these proce-
dures have been described elsewhere.
10
Briefly,
clinicians were educated about practices to con-
trol infection and harm resulting from catheter-
related bloodstream infections, a central-line cart
with necessary supplies was created, a checklist
was used to ensure adherence to infection-control
practices, providers were stopped (in nonemer-
gency situations) if these practices were not be-
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2727
ing followed, the removal of catheters was dis-
cussed at daily rounds, and the teams received
feedback regarding the number and rates of cath-
eter-related bloodstream infection at monthly and
quarterly meetings, respectively. In April 2004, a
letter and a baseline survey were sent to the chief
executive officers (CEOs) of the participating hos-
pitals. The letter outlined the evidence supporting
the use of chlorhexidine
1
and asked the CEOs to
stock chlorhexidine in their hospitals before im-
plementing the study intervention.
Measurement and Categorization of Data
Throughout the study, data on the number of
catheter-related bloodstream infections and cath-
eter-days were collected monthly from a trained,
hospital-based infection-control practitioner. Hos-
pitals were given the NNIS definition of catheter-
related bloodstream infection (
Fig. 1
). Study inves-
tigators asked members of the teams to adhere to
the NNIS definition of catheter-related blood-
stream infection during the study period. Three
ICUs changed the definition used from their own
to that of the NNIS. Infection-control staff at the
hospitals adjudicated contaminated cultures be-
fore submitting data for the study. We defined a
central catheter as a catheter that ends at or near
the heart or in a great vessel close to the heart,
which included peripherally inserted central cath-
eters, and the teams were explicitly instructed to
count the use of multiple lines in one patient as
1 catheter-day, in accordance with the NNIS
guidelines. To simplify data collection, the aver-
age duration of catheter use in individual patients
was not monitored.
To coincide with the implementation periods
for the study intervention, monthly data were ag-
gregated into 3-month periods (quarters). The
quarterly rate of infection was calculated as the
number of infections per 1000 catheter-days for
each 3-month period. Quarterly rates were as-
signed to one of eight categories on the basis of
when the study intervention was implemented:
at baseline, during the implementation period, or
during one of six 3-month intervals occurring up
to 18 months after implementation. We did not
collect data on who inserted the central catheters.
To our knowledge, no other infection-reducing
practices were implemented during our study.
Exposure, Outcomes, and Study Hypotheses
We modeled exposure to the study intervention,
after full implemention, according to six categori-
cal temporal variables, comparing values for those
variables with baseline values. The outcome was
the quarterly rate of catheter-related bloodstream
infection. The analysis included three character-
istics of the hospitals, obtained from the American
Hospital Association database: teaching status
(a binary variable), bed size (a continuous variable),
and geographic region (eight categories). Teaching
hospitals were required to be members of the
Council of Teaching Hospitals Health Systems and
to have been approved for residency training by
the Accreditation Council for Graduate Medical
Education or the American Osteopathic Associa-
tion. The primary study hypothesis was that the
rate of catheter-related bloodstream infection
would be reduced during the first 3 months after
implementation of the study intervention as com-
pared with baseline. A secondary hypothesis was
that the observed decrease in the rate of infection
between 0 and 3 months after implementation of
the study intervention would be sustained during
the subsequent observation period. We did not
evaluate the relative effectiveness of the separate
components of the intervention.
16p6
Presence of at least one of the following:
Fever (temperature, >38°C)
Chills
Hypotension
and
Signs and symptoms and positive results
not related to infection at another site
and
Presence of at least one of the following:
Common skin contaminant (e.g.,
diphtheroids, bacillus species,
propionibacterium species, coagulase-
negative staphylococci or micrococci)
cultured from two or more blood
samples drawn on separate
occasions
Common skin contaminant cultured from
at least one blood culture in a sample
from a patient with an intravascular
catheter
Positive antigen test on blood (e.g.,
Haemophilus influenzae, Streptococcus
pneumoniae, Neisseria meningitidis,
or group B streptococcus)
Presence of a recognized pathogen cultured
from one or more blood cultures
and
Organism cultured from blood not related
to infection at another site
AUTHOR:
FIGURE:
JOB: ISSUE:
4-C
H/T
RETAKE
SIZE
ICM
CASE
EMail
Line
H/T
Combo
Revised
AUTHOR, PLEASE NOTE:
Figure has been redrawn and type has been reset.
Please check carefully.
REG F
Enon
1st
2nd
3rd
Pronovost
1 of 1
12-28-06
ARTIST: ts
35526
or
Figure 1. Catheter-Related Bloodstream Infections
in Adults, as Defined by the National Nosocomial
Infections Surveillance System.
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Statistical Analysis
Because of the nonnormal distribution of the data
on catheter-related bloodstream infections, medi-
ans and interquartile ranges were used to sum-
marize the data. Medians were compared with
baseline values with the use of a two-sample Wil-
coxon rank-sum test. To explore the exposure–out-
come relationship, we used a generalized linear
latent and mixed model
18,19
with a Poisson distri-
bution for the quarterly number of catheter-related
bloodstream infections. In the model, we used ro-
bust variance estimation and included two-level
random effects to account for nested clustering
within the data, catheter-related bloodstream in-
fections within hospitals, and hospitals within
the geographic regions included in the study.
18,20
The addition of a third level of clustering for a
potential ICU effect (catheter-related bloodstream
infections within ICUs, ICUs within hospitals, and
hospitals within the geographic regions) did not
change the results. We adjusted for the hospital’s
teaching status and bed size in the model and ex-
plored interactions between the effect of the study
intervention (modeled as a continuous variable)
and teaching status and bed size. We conducted
a sensitivity analysis of these results in which only
ICUs with continuous data, including baseline
(preimplementation) data, were included. All re-
ported P values are two-sided; a P value of 0.05 or
less was considered to indicate statistical signifi-
cance. We used Stata software (version 9.1) for the
analysis. The study was approved by the institu-
tional review board of Johns Hopkins University
School of Medicine. Informed consent was waived
because the study was considered exempt from
review.
The AHRQ provided financial support for the
Keystone ICU project but had no role in the de-
sign or conduct of the study; the collection, man-
agement, analysis, or interpretation of the data;
the preparation, review, or approval of the manu-
script; or the decision to submit the manuscript
for publication. The MHA provided support for
the biannual statewide meetings but had no in-
fluence on the design, implementation, analysis,
or results of the study. The authors had full access
to the data and vouch for the accuracy and com-
pleteness of the data and the analysis.
R e s u l t s
Five of 108 participating ICUs were excluded: 4 be-
cause they did not track or report catheter-related
bloodstream infections, catheter-days, or both,
and 1 because it merged with another participat-
ing ICU, so that the combined data were used in
the analysis. The data were obtained from 67 hos-
pitals, of which 52% were teaching facilities. The
types of ICU included medical, surgical, cardiac
medical or surgical, neurologic, and surgical trau-
ma units and one pediatric unit. The ICUs repre-
sented 1625 (85%) of all ICU beds in Michigan.
Of 34 hospitals in Michigan that did not partici-
pate in the study, 27 (79%) had fewer than 100
beds; the total number of beds in the ICUs not
included in the study was 268.
Thus, 103 ICUs reporting data for 1981 ICU-
months and 375,757 catheter-days were included
in the final analysis. The characteristics of the
ICUs according to the study period are summa-
rized in
Table 1
. Baseline data on catheter-related
bloodstream infections at the participating ICUs
Table 1. Characteristics of 103 Participating ICUs, According to the Period of Implementation of the Intervention
to Reduce the Rate of Catheter-Related Bloodstream Infections.
Period No. of ICUs
No. of
Catheter-Days
per Month Teaching Hospital No. of Beds
median
(interquartile range) %
median
(interquartile range)
March to May 2004* 40 154 (94–258) 83 404 (268–609)
June to August 2004 35 146 (72–228) 57 336 (218–610)
September to November 2004 17 181 (80–275) 59 299 (190–393)
After November 2004 11 172 (48–279) 73 288 (181–917)
* Baseline data were not collected by ICUs implementing the study intervention during the baseline (preimplementation)
period.
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2729
are summarized in
Table 2
, according to the
teaching status and bed size of the hospitals.
When the Keystone ICU project was launched, 13
of the 67 hospitals (19%) included chlorhexidine
in the central-line kits used in the ICUs. Six weeks
after the study letter was sent to CEOs at the 67
participating hospitals, 56 (84%) stocked chlorhex-
idine, 46 (69%) stocked the agent in the ICU, and
43 (64%) stocked it in central-line carts.
The total number of catheter-days changed
little during the study. In ICUs that implemented
the study intervention during the 3 months (June
to August 2004) after baseline data were col-
lected (
Table 1
), the mean number of catheter-
days per month was 4779. During the follow-up
period, the mean number of catheter-days per
month ranged from 4757 at 4 to 6 months after
implementation of the intervention to 5469 at
10 to 12 months after implementation.
The overall median rate of catheter-related
bloodstream infection decreased from 2.7 (mean,
7.7) infections per 1000 catheter-days at baseline
to 0 (mean, 2.3) at 0 to 3 months after implemen-
tation of the study intervention (P≤0.002) and
was sustained at 0 (mean, 1.4) during 18 months
of follow-up (
Table 3
). A significant decrease
was observed in both teaching and nonteaching
hospitals and in small hospitals (<200 beds) and
large hospitals (≥200 beds) (
Table 3
).
The multilevel Poisson regression model showed
a significant decrease in rates of catheter-related
bloodstream infection during all study periods
as compared with baseline rates, with incidence-
rate ratios continuously decreasing from 0.62
(95% confidence interval [CI], 0.47 to 0.81) at 0 to
3 months to 0.34 (95% CI, 0.23 to 0.50) at 16 to
18 months after implementation of the study in-
tervention (
Table 4
). There was a significant in-
teraction between the intervention and bed size:
the intervention was modestly more effective in
small hospitals, with an incidence-rate ratio of
0.97 (95% CI, 0.96 to 0.99; P<0.001) for each
100-bed decrease in the size of the hospital. The
results of a sensitivity analysis of data from the
53 ICUs reporting data continuously from baseline
onward were similar to those of the primary analy-
sis, with incidence-rate ratios decreasing from 0.62
(95% CI, 0.46 to 0.85) at 0 to 3 months to 0.15 (95%
CI, 0.07 to 0.32) at 16 to 18 months of follow-up.
Dis c u s s ion
The goal of the MHA Keystone ICU project was to
improve patient safety in ICUs in Michigan. The
analysis was focused on an intervention to reduce
the rate of catheter-related bloodstream infection
that was implemented in 103 ICUs in Michigan in
2004. Within 3 months after implementation, the
median rate of infection was 0, a rate sustained
throughout the remaining 15 months of follow-up.
All types of participating hospitals realized a sim-
ilar improvement.
Table 2. Baseline Data.
Characteristic No. of ICUs Baseline Period
No. of
Infections Catheter-Days
No. of
Infections per 1000
Catheter-Days
median (interquartile range)
All hospitals 55* 2 (1–3) 511 (220–1091) 2.7 (0.6–4.8)
Teaching status
Teaching 33 2 (1–4) 744 (377–1134) 2.7 (1.3–4.7)
Nonteaching 22 1 (0–2) 306 (194–608) 2.6 (0–4.9)
No. of beds
<200 13 1 (0–1) 247 (75–377) 2.1 (0–3.0)
200–299 12 2 (1–6) 595 (338–1670) 3.2 (0.3–4.3)
300–399 12 2 (1–3) 902 (184–1376) 2.7 (1.7–5.8)
≥400 18 2 (1–3) 616 (424–1102) 2.0 (1.3–4.7)
* Of the 103 participating ICUs, 48 did not contribute baseline data — 40 because they implemented the intervention
at the initiation of the study and 8 because they did not report baseline data.
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This study showed that a large-scale project
focused on reducing the incidence of catheter-
related bloodstream infection is feasible and can
have important public health consequences. Cur-
rent efforts to improve patient safety in the United
States are fragmented, with few large-scale im-
provements documented.
21-23
The ability to mea-
sure and evaluate the effect of interventions to
increase patient safety is still underdeveloped.
21,24
In this project, monitoring catheter-related blood-
stream infection rates was possible because of
the existence of an infrastructure — specifically,
congressional funding to develop and maintain
the NNIS and a staff of hospital-based infection-
control practitioners. Similar infrastructure does
not exist for most other issues related to patient
safety.
Important reductions in morbidity and health
care costs could be achieved if the intervention
to reduce catheter-related bloodstream infections
could be introduced successfully nationwide or
worldwide. Given the results of the study, many
of the estimated 80,000 infections, up to 28,000
deaths, and $2.3 billion in costs attributed to
these infections annually in the United States
could be reduced. The intervention was imple-
mented without the use of expensive technology
or additional ICU staffing. However, the MHA and
AHRQ funded this intervention, and the partici-
pating hospitals provided staff to implement it.
The estimated costs associated with catheter-
related bloodstream infections vary, ranging from
$11,971 to $54,000 per infection.
3,25
Given that
the participating ICUs had reported 695 catheter-
related bloodstream infections annually before the
study, implementing the study intervention offers
a strategy to improve clinical outcomes and re-
duce costs.
The study has several limitations. First, the
design reduces the ability to make a causal con-
nection between the intervention and reduced
rates of catheter-related bloodstream infection.
Randomized assignment of the intervention and
of the time of implementation was not feasible,
because all the ICU teams wanted to implement
the intervention and to decide for themselves when
to do so. However, several factors support a true
and strong association between the intervention
and a reduction in rates of catheter-related blood-
stream infection: variability in the timing of im-
plementation reduced any effect of seasonal trend
on the baseline rates of infection, reduced infec-
tion rates were sustained and fell further with
continued exposure to the intervention, and simi-
lar large decreases in infection rates were not ob-
served outside Michigan during the study period.
Second, potential underreporting of catheter-
related bloodstream infections and the lack of
Table 3. Rates of Catheter-Related Bloodstream Infection from Baseline (before Implementation of the Study Intervention) to 18 Months
of Follow-up.*
Study Period No. of ICUs No. of Bloodstream Infections per 1000 Catheter-Days
Overall
Teaching
Hospital
Nonteaching
Hospital <200 Beds ≥200 Beds
median (interquartile range)
Baseline 55 2.7 (0.6–4.8) 2.7 (1.3–4.7) 2.6 (0–4.9) 2.1 (0–3.0) 2.7 (1.3–4.8)
During implementation 96 1.6 (0–4.4)† 1.7 (0–4.5) 0 (0–3.5) 0 (0–5.8) 1.7 (0–4.3)†
After implementation
0– 3 mo 96 0 (0–3.0)‡ 1.3 (0–3.1)† 0 (0–1.6)† 0 (0–2.7) 1.1 (0–3.1)‡
4–6 mo 96 0 (0–2.7)‡ 1.1 (0–3.6)† 0 (0–0)‡ 0 (0–0)† 0 (0–3.2)‡
7–9 mo 95 0 (0–2.1)‡ 0.8 (0–2.4)‡ 0 (0–0)‡ 0 (0–0)† 0 (0–2.2)‡
10–12 mo 90 0 (0–1.9)‡ 0 (0–2.3)‡ 0 (0–1.5)‡ 0 (0–0)† 0.2 (0–2.3)‡
13–15 mo 85 0 (0–1.6)‡ 0 (0–2.2)‡ 0 (0–0)‡ 0 (0–0)† 0 (0–2.0)‡
16–18 mo 70 0 (0–2.4)‡ 0 (0–2.7)‡ 0 (0–1.2)† 0 (0–0)† 0 (0–2.6)‡
* Because the ICUs implemented the study intervention at different times, the total number of ICUs contributing data for each period varies.
Of the 103 participating ICUs, 48 did not contribute baseline data. P values were calculated by the two-sample Wilcoxon rank-sum test.
† P≤0.05 for the comparison with the baseline (preimplementation) period.
‡ P≤0.002 for the comparison with the baseline (preimplementation) period.
Copyright © 2006 Massachusetts Medical Society. All rights reserved.
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2731
baseline data from ICUs that immediately imple-
mented the intervention when the project was
launched could have created a measurement bias
that exaggerated the results. However, the infec-
tion rates were collected and reported according
to the guidelines of the NNIS by hospital infec-
tion-control practitioners who were independent
of the ICU staff implementing the intervention.
Furthermore, a sensitivity analysis showed little
change in the association between the interven-
tion and outcomes when only ICUs for which
complete data (including baseline data) were avail-
able were included.
Third, data on the organisms causing catheter-
related bloodstream infections were not collect-
ed, limiting insight into the mechanism of the
observed benefit. Fourth, we did not evaluate
compliance with the study intervention, because
limited resources prevented observation of cen-
tral-line placements. Fifth, we could not evaluate
the relative importance of individual components
of the multifaceted intervention or of the safety-
culture intervention. However, our goal was max-
imal improvement of patient safety, and the study
program offered the greatest probability of re-
ducing catheter-related bloodstream infections.
Sixth, we did not obtain data on catheter-related
bloodstream infection rates from nonparticipat-
ing ICUs. Nevertheless, the ICUs that participated
in the study accounted for 85% of ICU beds in
Michigan. Last, we studied ICUs in only one state,
which may limit the ability to generalize our find-
ings. Nevertheless, a wide variety of types of hos-
pital and ICU were studied.
In summary, catheter-related bloodstream in-
fections are expensive, prevalent, and often fatal.
As part of the Michigan statewide patient-safety
initiative, we implemented a simple and inexpen-
sive intervention to reduce these infections in
103 ICUs. Coincident with the intervention, the
median rate of infection decreased from 2.7 per
1000 catheter-days at baseline to 0 within the first
3 months after the implementation of the inter-
vention. The benefit from the intervention was
sustained, and there was a reduction in the rate
of catheter-related bloodstream infection of 66%
at 16 to 18 months after implementation. Broad
use of this intervention could significantly reduce
morbidity and the costs of care associated with
catheter-related bloodstream infections.
Supported by a grant from the AHRQ (1UC1HS14246) for the
Keystone ICU project.
Dr. Pronovost reports receiving consulting fees from CriticalMed
and DocuSys and holding equity ownership in DocuSys and
Visicu; Dr. Berenholtz, receiving consulting fees from VHA; Dr.
Cosgrove, receiving grant support from Merck, receiving con-
sulting fees from Cubist Pharmaceuticals, and being a member
of an advisory board for Ortho-McNeil; Dr. Hyzy, receiving lec-
ture fees from Eli Lilly and Wyeth; and Dr. Bander, receiving
consulting fees and lecture fees from Eli Lilly, Elan Pharmaceu-
ticals, and the Surviving Sepsis Campaign. No other potential
conflict of interest relevant to this article was reported.
We thank C.G. Holzmueller for assistance in editing; P. Lip-
sett and T. Perl for thoughtful review of a draft of the manu-
script; and the MHA Keystone Center and all the ICU teams in
Michigan for their tremendous efforts, leadership, and courage
and their dedication to improving the quality of the care and
safety of their patients. (For a list of the participating hospitals,
see Appendix B in the Supplementary Appendix.)
Table 4. Incidence-Rate Ratios for Catheter-Related Bloodstream Infections.*
Variable
Incidence-Rate Ratio
(95% CI) P Value
Study period
Baseline 1.00
During implementation 0.76 (0.57–1.01) 0.063
After implementation
0–3 mo 0.62 (0.47–0.81) 0.001
4–6 mo 0.56 (0.38–0.84) 0.005
7–9 mo 0.47 (0.34–0.65) <0.001
10–12 mo 0.42 (0.28–0.63) <0.001
13–15 mo 0.37 (0.20–0.68) 0.001
16–18 mo 0.34 (0.23–0.50) <0.001
Teaching hospital 1.34 (0.73–2.46) 0.35
Bed size (per 100 beds) 1.03 (0.97–1.09) 0.33
* Incidence-rate ratios were calculated with the use of a generalized linear la-
tent and mixed model (Rabe-Hesketh and Skrondal
18
), with robust variance
estimation and random effects to account for clustering of catheter-related
bloodstream infections within hospitals and clustering of hospitals within
geographic regions. Rates of catheter-related bloodstream infection during
and after implementation of the study intervention were compared with
baseline (preimplementation) values, adjusted for the hospital’s teaching
status and number of beds.
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New England Journal of Medicine
CORRECTION
An Intervention to Decrease Catheter-Related
Bloodstream Infections in the ICU
An Intervention to Decrease Catheter-Related Bloodstream Infections
in the ICU . In the first paragraph under the ``Measurement and Cat-
egorization of Data´´ heading (page 2727), the sixth sentence should
have read, ``We defined a central catheter as a catheter that ends
at or near the heart or in a great vessel close to the heart, which
included peripherally inserted central catheters, and the teams were
explicitly instructed to count the use of multiple lines in one patient
as 1 catheter-day, in accordance with the NNIS guidelines,´´ rather
than ``great vessel close to the heart, and the teams were explicitly
instructed to exclude peripherally inserted central catheters and to
count the use.´´ The text has been corrected on the Journal’s Web
site at www.nejm.org.
N Engl J Med 2007;356:2660-a
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