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EXTENDED REPORT
Non-steroidal anti-inflammatory drugs for spinal
pain: a systematic review and meta-analysis
Gustavo C Machado,
1
Chris G Maher,
1
Paulo H Ferreira,
2
Richard O Day,
3
Marina B Pinheiro,
2
Manuela L Ferreira
1,4
ABSTRACT
Background While it is now clear that paracetamol is
ineffective for spinal pain, there is not consensus on the
efficacy of non-steroidal anti-inflammatory drugs
(NSAIDs) for this condition. We performed a systematic
review with meta-analysis to determine the efficacy and
safety of NSAIDs for spinal pain.
Methods We searched MEDLINE, EMBASE, CINAHL,
CENTRAL and LILACS for randomised controlled trials
comparing the efficacy and safety of NSAIDs with
placebo for spinal pain. Reviewers extracted data,
assessed risk of bias and evaluated the quality of
evidence using the Grade of Recommendations
Assessment, Development and Evaluation approach.
A between-group difference of 10 points (on a 0–100
scale) was used for pain and disability as the smallest
worthwhile effect, as well as to calculate numbers
needed to treat. Random-effects models were used to
calculate mean differences or risk ratios with 95% CIs.
Results We included 35 randomised placebo-controlled
trials. NSAIDs reduced pain and disability, but provided
clinically unimportant effects over placebo. Six
participants (95% CI 4 to 10) needed to be treated with
NSAIDs, rather than placebo, for one additional
participant to achieve clinically important pain reduction.
When looking at different types of spinal pain, outcomes
or time points, in only 3 of the 14 analyses were the
pooled treatment effects marginally above our threshold
for clinical importance. NSAIDs increased the risk of
gastrointestinal reactions by 2.5 times (95% CI 1.2 to
5.2), although the median duration of included trials
was 7 days.
Conclusions NSAIDs are effective for spinal pain, but
the magnitude of the difference in outcomes between
the intervention and placebo groups is not clinically
important. At present, there are no simple analgesics
that provide clinically important effects for spinal pain
over placebo. There is an urgent need to develop new
drug therapies for this condition.
INTRODUCTION
Spinal pain (neck or low back pain) is the leading
cause of disability worldwide,
12
and commonly
managed in general practice by prescription of
medicines.
34
Clinical guidelines recommend non-
steroidal anti-inflammatory drugs (NSAIDs) as a
second-line analgesic after paracetamol, with third
choice being opioids.
5
However, recent
meta-analyses have shown that paracetamol is inef-
fective,
67
and opioids appear only to offer small
benefits for this condition.
8
Thus, although the use
of NSAIDs has fallen in the past decade,
9
their use
could rapidly rise, given the lack of efficacy of para-
cetamol and increased awareness of risks associated
with opioid use.
10 11
There is still not consensus on the efficacy of
NSAIDs for spinal pain. The most recent
meta-analysis excluded participants with acute low
back pain or neck pain,
12
and to date no reviews
have investigated NSAID injections or topical for-
mulations in this population. Furthermore, previous
meta-analyses have reported standardised mean dif-
ferences (MD) as effect sizes, which are non-
intuitive and difficult to interpret;
13
thus better
measures of treatment effects, such as numbers
needed to treat (NNT), are likely to enhance inter-
pretability for the clinician. There is also concern
about the cardiovascular safety of cyclo-oxygenase-2
(COX-2) inhibitors, while serious gastrointestinal
adverse reactions are more closely linked to non-
selective NSAIDs,
14
although all NSAIDs have been
associated with cardiovascular and gastrointestinal
risks.
15
Thus, there is far greater need to understand
the efficacy and safety of this medicine for spinal
pain.
Therefore, the aim of this systematic review was
to investigate the efficacy and safety of NSAIDs
compared with placebo in patients with spinal pain,
with or without radicular pain. We also aimed to
evaluate whether trial characteristics or methods
are associated with estimates of treatment effect.
METHODS
Literature search
We followed the Preferred Reporting Items for
Systematic Reviews and Meta-analyses (PRISMA)
statement,
16
and prospectively registered the review
protocol on the International Prospective Register
of Systematic Reviews (CRD42015023746). We
searched MEDLINE, EMBASE, CINAHL,
CENTRAL and LILACS from their inception to
February 2016. The search strategy was constructed
based on a combination of the following keywords
and their variations: neck pain, back pain,
lumbago, sciatica, anti-inflammatory, placebo and
randomised controlled trial. There were no restric-
tions of language or publication period.
Translations were obtained for non-English studies
(two trials). The complete search strategy is shown
in online supplementary table S1. One author
(GCM) performed the first selection of studies
based on titles and abstracts, and two authors
(GCM and MBP) independently screened full texts.
We also searched for potentially eligible trials in the
reference lists of included studies and relevant
1269
Machado GC, etal. Ann Rheum Dis 2017;76:1269–1278. doi:10.1136/annrheumdis-2016-210597
Clinical and epidemiological research
To cite: MachadoGC,
MaherCG, FerreiraPH,
etal. Ann Rheum Dis
2017;76:1269–1278.
Handling editor Tore K Kvien
►Additional material is
published online only. To view
please visit the journal online
(http://dx.doi.org/10.1136/
annrheumdis-2016-210597).
1The George Institute for Global
Health, Sydney Medical School,
University of Sydney, Sydney,
New South Wales, Australia
2Arthritis and Musculoskeletal
Research Group, Faculty of
Health Sciences, University of
Sydney, Sydney, New South
Wales, Australia
3Department of Clinical
Pharmacology, St Vincent’s
Hospital & University of New
South Wales, Sydney, New South
Wales, Australia
4Institute of Bone and Joint
Research, The Kolling Institute,
Sydney Medical School,
University of Sydney, Sydney,
New South Wales, Australia
Correspondence to
Gustavo C Machado, The
George Institute for Global
Health, PO Box M201,
Missenden Road, Camperdown,
Sydney, NSW 2050, Australia;
gmachado@georgeinstitute.
org.au
Received 27 September 2016
Revised 20 December 2016
Accepted 27 December 2016
Published Online First
20January2017
group.bmj.com on June 12, 2017 - Published by http://ard.bmj.com/Downloaded from
systematic reviews. We used consensus to resolve any
disagreement.
Study selection
Only randomised placebo-controlled trials published in peer-
reviewed journals and investigating the effects and safety of
NSAIDs for spinal pain were included in this review. Trials had
to include participants with neck or low back pain, with or
without radicular pain. Trials that included mixed populations
were included if they reported separate data for participants
with spinal pain. We included trials investigating acute or
chronic spinal pain of any intensity and eligible trials had to
compare any class, formulation or route of administration
(topical, oral or injection) of NSAIDs with a matching placebo.
Only trials that reported patient-relevant outcomes, such as pain
intensity, disability status, quality-of-life or adverse events were
included. The dose and frequency of NSAIDs intake were not
restricted, and we investigated the effects of both non-selective
NSAIDs (eg, acetic acids, enolic acids, propionic acids, salicy-
lates) and COX-2 inhibitors. We excluded trials of participants
with serious spinal pathology (cancer, infectious diseases or
cauda equina syndrome). Trials evaluating postoperative anal-
gesia using NSAIDs in participants with spinal pain were
excluded, as were non-randomised controlled trials, review arti-
cles, guidelines and observational studies.
Data extraction and quality assessment
We used a standardised data extraction form to record the
characteristics of included participants, NSAID class and dose,
route of administration, outcomes and duration of follow-up.
Two reviewers (GCM and MBP) independently recorded
the sample size, means and SDs for pain, disability and
quality-of-life measures. We extracted these data following a
hierarchical order: mean difference (MD), change scores and
post-treatment scores. When medians, IQRs, ranges or SEs were
reported, we used previously reported formulae to estimate
means and SDs.
17
According to recommendations in the
Cochrane Handbook,
18
we extracted data from the first period
of crossover randomised trials, and in multi-arm trials we
extracted data from all groups and divided the number of parti-
cipants in the control group by the number of comparisons.
For the safety outcomes, we extracted the number of partici-
pants reporting any adverse event, any serious adverse event (as
defined by each trial or events including myocardial infarction
and/or stroke), the number of dropouts due to adverse events
and the number of participants reporting gastrointestinal
adverse reactions. We also extracted the number of participants
taking additional analgesics and the number of tablets consumed
per day. We contacted authors of included trials to clarify any
relevant information or to request additional data in case of
incomplete reporting. Consensus or a third reviewer (MLF) was
used to resolve any disagreement.
The Cochrane Collaboration’s tool was used to assess the risk
of bias of included studies by two independent reviewers (GCM
and MBP).
19
The quality of the evidence from each pooled ana-
lysis was evaluated using the Grade of Recommendations
Assessment, Development and Evaluation (GRADE) approach.
20
The quality of evidence was downgraded by one level according
to the following criteria: limitation of study design (more than a
quarter of studies considered at serious risk of bias), inconsist-
ency of results (substantial heterogeneity, I
2
>50%), imprecision
(pooled sample size <300), indirectness (dissimilar population,
intervention, outcomes and time points) and publication bias
(funnel plot assessment and Egger’s test two-tailed p<0.1).
Consensus was used to resolve any disagreement. The quality of
evidence was then judged as high, moderate, low or very low.
Data synthesis and analysis
Trials were pooled for common outcomes and time points. As
our primary analysis we present overall pooled estimates includ-
ing all available trials, and as a secondary analysis we present
separate pooled effects for neck pain, acute/chronic low back
pain and sciatica. We defined a follow-up period <2 weeks as
immediate-term, and a follow-up between 2 weeks and
3 months as short-term. When more than one time point was
available for the same definition, we extracted data at 1 week
for immediate-term, or at 8 weeks for short-term. Although we
attempted to extract data for medium (>3 months but
<12 months) and long-term (≥12 months) follow-ups, no trials
reported data for these time points.
Pain outcome measures reported in included trials were visual
analogue scales (range, 0–100), or numerical rating scales
(range, 0–10). These two pain measures are highly correlated
and can be used interchangeably when transformed.
21
The dis-
ability scale used in trials was the Roland-Morris Disability
Questionnaire (range, 0–24). Pain and disability scores were con-
verted to a common 0-point (no pain or disability) to 100-point
(worst possible pain or disability) scale to facilitate the interpret-
ation of our results, and because smallest worthwhile effects for
pain and disability in this population are often reported in a 0–
100 scale.
22–24
Quality-of-life measures included the 12-item or
the 36-item Short Form (SF) Health Survey (range, 0–100); no
score conversion was needed for this outcome.
A between-group difference of 10 points (on a 0–100 scale)
for pain, disability and quality-of-life was considered as the smal-
lest worthwhile effect;
22
the mean effect sizes below this thresh-
old were considered clinically unimportant. The smallest
worthwhile effect describes the smallest effect of intervention
(compared with placebo) that patients perceive as important,
and is critical for clinical decision-making.
25
We used
random-effects models to calculate MD or risk ratios (RR) and
95% CIs. We also present the results for the pain intensity ana-
lyses as numbers needed to treat (NNT), using the method pro-
posed by Norman.
26
This expresses the number of patients who
need to be treated with an NSAID rather than placebo, for one
additional person to benefit (based on a clinically important
change of 10 points on a 0–100 pain scale; and allowing for the
proportion of patients who were improved, the same and dete-
riorated in NSAID and placebo groups). All analyses were con-
ducted using Comprehensive Meta-Analysis V.2 (Biostat,
Englewood, New Jersey, USA).
Secondary exploratory analysis
We conducted subgroup analyses to explore the influence of dif-
ferent factors on our estimates of treatment effects. We used
meta-regression to generate the difference in effect sizes (with
95% CI) and p values between subgroups for pain at immediate-
term. Subgroups were defined in terms of risk of bias judge-
ments (low, unclear or high), form of drug administration
(topical, oral or injection) and type of NSAID (COX-2 inhibi-
tors or non-selective NSAIDs). We also investigated the differ-
ence of effect sizes of discontinued drugs (eg, rofecoxib and
valdecoxib) and currently marketed NSAIDs, given the aim of
this review in informing current best practice.
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RESULTS
Initial search and results
Our search resulted in a total of 5208 individual records. After
the screening of titles and abstracts, two independent reviewers
assessed 302 full-text articles. We included 35 randomised trials
after full-text examination with data for 6065 participants with
spinal pain (figure 1).
27–61
Twenty-two trials investigated the
effects of NSAIDs for low back pain, of which 11 included par-
ticipants with acute back pain and 11 (10 published reports)
included participants with chronic low back pain. Eleven trials
investigated participants with sciatica and two included neck
pain only. The median treatment duration in included trials was
7 (IQR, 5–7) days. NSAIDs were mostly administered orally, but
five trials used intravenous or intramuscular injection,
35 37–39 59
and three used a topical formulation, such as a gel, patch or
cream.
51 53 56
Nine trials had a three-arm parallel design and
two were randomised crossover trials. These trials compared
two different drugs, or two different dosages of the same drug
with a matching placebo. Online supplementary table S2 pro-
vides more detail on the characteristics of included trials and
the medications evaluated.
The risk of bias assessment (see online supplementary figure
S1) shows that overall, studies had no serious risk of bias.
However, about half of the trials had at least one bias domain
judged as high risk. A third of included trials reported an appro-
priate method of randomisation, and only four reported suitable
allocation concealment. Nearly all trials were therapist and
assessor-blinded, but 20% of trials had high dropout rates
(>15%). Seven trials did not report relevant outcomes or failed
to report results previously described in their methods and were
judged at high risk of reporting bias. Eleven trials were judged
at high risk for the ‘other’bias domain as they reported that
pharmaceutical companies that funded the trial were involved in
running the study, analysing the data or writing the manuscript.
The risk of bias assessment for each individual trial is shown in
online supplementary figure S2. The inspection of the funnel
plot including all trials reporting data for immediate pain reduc-
tion and the non-significant Egger’s test ( p=0.86) revealed no
publication bias (see online supplementary figure S3).
Therefore, none of our meta-analyses was downgraded for pub-
lication bias according to the GRADE approach. Data extracted
from individual trials and calculations of effect sizes are shown
in online supplementary tables S3 and S4.
Efficacy of NSAIDs for spinal pain
Pooling of all included trials revealed moderate-quality evidence
that NSAIDs reduced pain in the immediate (MD −9.2, 95% CI
−11.1 to −7.3) and short-term (MD −7.7, 95% CI −11.4 to
−4.1) compared with placebo (figure 2). The NNT to achieve a
clinically significant effect of NSAIDs over placebo on pain
reduction in the immediate-term was 5 (95% CI 4 to 6) and 6
(95% CI 4 to 10) in the short-term. The effects of NSAIDs on
disability were slightly smaller than for pain, with effect at
immediate-term follow-up being −8.1 (95% CI −11.6 to −4.6),
and at short-term −6.1 (95% CI −9.5 to −2.8) (figure 3). The
magnitude of the difference in outcomes between the interven-
tion and placebo groups, however, was less than the 10-point
threshold for clinical importance.
There was high-quality evidence of clinically unimportant
effects of NSAIDs compared with placebo for the physical
component of the SF-12 (MD −2.9, 95% CI −3.7 to −2.1),
and no effects over placebo were found for the mental compo-
nent (MD −0.3, 95% CI −1.2 to 0.6). None of the included
studies used the SF-36 to measure quality-of-life. Table 1 pro-
vides more detailed information on the summary of findings
and the GRADE assessment. None of the included trials
reported medium-term or long-term effects of NSAIDs.
Safety of NSAIDs for spinal pain
For the safety analyses, we included up to 21 trials (5153 parti-
cipants) with median treatment duration of 7 (IQR, 5–7) days
(figure 4). No difference in any event rate between NSAIDs and
placebo was found (RR 1.1, 95% CI 1.0 to 1.2). Only two trials
including 635 participants reported serious adverse event data
and again there was no difference between groups (RR 1.5,
95% CI 0.4 to 5.2). Similarly, nine trials with 3283 participants
revealed no difference in the number of dropouts due to
adverse events (RR 1.0, 95% CI 0.6 to 1.6). However, we
found a significantly higher number of participants in the
NSAIDs group reporting gastrointestinal adverse events com-
pared with placebo (RR 2.5, 95% CI 1.2 to 5.2); 28/702 partici-
pants taking NSAIDs had gastrointestinal adverse reactions
compared with 9/465 in the placebo groups. Overall, these
results were based on high-quality evidence according to the
GRADE evaluation.
Use of rescue medication
The use of rescue medication was measured in a variety of ways
in eight trials, such as the number of participants taking add-
itional analgesics and the number of tablets taken per day. Four
trials revealed moderate-quality evidence of no difference in the
number of participants taking an additional analgesic (RR 1.0,
95% CI 0.6 to 1.4). However, pooling of four trials showed
high-quality evidence that participants taking NSAIDs required
less tablets/day of a rescue medication (MD –0.4, 95% CI −0.5
to −0.3), a difference that is arguably not clinically important.
Figure 1 Study selection. CENTRAL, Cochrane Central Register of
Controlled Trials. *Number of citations listed for each database includes
duplicates.
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Secondary exploratory analysis
Results from our meta-regression analyses showed that trials
with low risk of selection bias had larger effects (MD −11.2,
95% CI −13.9 to −8.5) than trials judged at unclear risk (MD
−6.7, 95% CI −8.6 to −4.9). The difference between these sub-
groups (MD −4.2, 95% CI −7.7 to −0.8) was statistically sig-
nificant ( p=0.02). COX-2 inhibitors had larger effects (MD
−13.4, 95% CI −15.7 to −11.1) compared with non-selective
NSAIDs (MD −7.7, 95% CI −9.8 to −5.6). This difference was
Figure 2 Mean differences for pain in placebo-controlled trials on efficacy of non-steroidal anti-inflammatory drugs (NSAIDs) for spinal pain. Pain
is expressed on scale of 0–100. Immediate-term=follow-up ≤2 weeks; short-term=follow-up >2 weeks but ≤3 months; LBP, low back pain. Studies
ordered chronologically within subgroups.
1272 Machado GC, etal. Ann Rheum Dis 2017;76:1269–1278. doi:10.1136/annrheumdis-2016-210597
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also statistically significant (MD −5.7, 95% CI −9.4 to −1.9;
p=0.003), but of questionable clinical relevance. There was no
difference between the effect sizes of discontinued drugs com-
pared with currently marketed NSAIDs (MD 0.3, 95% CI −3.7
to 4.3; p=0.88), although no trials investigating celecoxib were
found (table 2). Different delivery routes resulted in similar
effects compared with a matching placebo: topical (MD −13.2,
95% CI −18.5 to −7.9), oral (MD −8.5, 95% CI −10.4 to
−6.6) and injection (MD −9.5, 95% CI −14.7 to −4.4).
DISCUSSION
Our review of 35 randomised placebo-controlled trials demon-
strates that NSAIDs are effective in reducing pain and disability in
patients with spinal pain, although treatment effects above those
of placebo are small and arguably not clinically important. For
every six patients treated with NSAIDs, rather than placebo, only
one additional patient would benefit considering a between-group
difference of 10 points for clinical importance in the short-term.
Furthermore, when looking at different spinal pain, outcomes or
time points in only 3 of the 14 analyses were the pooled effects
only marginally above our 10-point threshold for clinical rele-
vance. NSAIDs were associated with higher number of patients
reporting gastrointestinal adverse effects in the short-term
follow-up (ie, <14 days). No data on safety at medium-term or
long-term follow-ups were provided by included trials.
The strengths of our review include that it was prospectively
registered and followed the PRISMA recommendations, includ-
ing the use of GRADE to appraise the quality of the evidence.
We were able to identify a significantly larger number of trials
than past reviews,
12 62–70
which have often limited their inclu-
sion criteria to a specific language, population or type of
NSAID. Including more studies (35 randomised placebo-
controlled trials) enabled us to conduct a more thorough evalu-
ation of the effects of NSAIDs for various forms of spinal pain,
and to include a range of forms of drug administration. We have
also provided valuable information on pooled treatment effects
for specific populations, including neck pain, acute/chronic low
back pain and sciatica. Furthermore, we have provided clinically
interpretable estimates on a 0–100 scale, and compared our
effect sizes with a predetermined smallest worthwhile effect of
10 points, which reflects the smallest effect of the intervention
on outcomes compared with placebo that patients would con-
sider meaningful or important.
22
Given physicians often find
the interpretation of effect sizes reported in meta-analysis chal-
lenging,
71
we have also presented our results on pain reduction
as the NNT for a clinically significant effect of NSAIDs over
placebo. Moreover, potential factors that could have influenced
our treatment effects, such as risk of bias judegments, class of
NSAIDs and route of administration, were investigated through
meta-regression analyses. Although COX-2 inhibitors showed
larger effects than non-selective NSAIDs on pain reduction, the
size of the difference is of arguable clinical relevance. COX-2
inhibitors trials included in our review were fairly recent (all
were conducted after 2003) and substantially larger (mean
sample size of 280). They were also more likely to report safety
outcomes than older trials.
Figure 3 Mean differences for disability in placebo-controlled trials on efficacy of non-steroidal anti-inflammatory drugs (NSAIDs) for spinal pain.
Disability is expressed on scale of 0–100. Immediate-term=follow-up ≤2 weeks; short-term=follow-up >2 weeks but ≤3 months; LBP, low back
pain. Studies ordered chronologically within subgroups.
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Our review has some limitations. First, we did not find any
trials investigating the efficacy and safety of celecoxib versus
placebo, a commonly used COX-2 selective drug. Second,
some of the trials included in our meta-analysis used drugs that
are discontinued or are no longer commercialised in major
markets (eg, rofecoxib and valdecoxib), but our
meta-regression revealed that this was not a factor that influ-
enced our estimates; discontinued drugs (MD −8.9, 95% CI
−10.8 to −7.0) had similar effects as currently marketed
NSAIDs (MD −9.3, 95% CI −12.1 to −6.5). Third, there is no
evidence on the long-term effects and safety of NSAIDs, as the
median follow-up time was 1 week in included trials, with
some treatment schedules lasting <1 day. Fourth, our overall
pooled estimates resulted in substantial between-trial hetero-
geneity (I
2
ranged from 59% to 87%), which, however, was
found considerably reduced in the stratified meta-analyses
according to the type of spinal pain (ie, neck pain, acute/
chronic low back pain, or sciatica). Finally, another limitation
of our study is that there were very few trials on neck pain,
and none on whiplash.
Table 1 Summary of findings and quality of evidence assessment
Summary of findings Quality of evidence assessment (GRADE)
Overall Trials Participants I
2
, % MD (95% CI) Study limitation Inconsistency Imprecision Quality
Immediate-term
Pain 23 5217 59 –9.2 (−11.1 to −7.3) None –1 None Moderate
Disability 12 2667 87 −8.1 (−11.6 to −4.6) None –1 None Moderate
Short-term
Pain 9 2611 81 −7.7 (−11.4 to −4.1) None –1 None Moderate
Disability 8 2086 85 −6.1 (−9.5 to −2.8) None –1 None Moderate
Quality-of-life (PC) 4 1330 0 −2.9 (−3.7 to −2.1) None None None High
Quality-of-life (MC) 4 1330 15 −0.3 (−1.2 to 0.6) None None None High
Neck pain
Immediate-term
Pain 2 225 36 −16.3 (−20.6 to −12.0) None None –1 Moderate
Disability 2 225 98 −12.2 (−34.3 to 10.0) None –1–1Low
Acute low back pain
Immediate-term
Pain 5 814 26 −6.4 (−10.3 to −2.5) None None None High
Disability 3 476 43 −7.1 (−12.4 to −1.9) None None None High
Short-term
Pain 1 120 0 −1.0 (−5.9 to 3.9) None None –1 Moderate
Disability 1 120 0 −0.4 (−5.4 to 4.5) None None –1 Moderate
Chronic low back pain
Immediate-term
Pain 9 2537 52 −11.1 (−13.8 to −8.4) None –1 None Moderate
Disability 6 1752 30 −8.4 (−10.6 to −6.3) None None None High
Short-term
Pain 7 2277 60 −9.8 (−12.7 to −7.0) None –1 None Moderate
Disability 6 1752 87 −7.9 (−11.8 to −4.0) None –1 None Moderate
Sciatica
Immediate-term
Pain 7 1641 0 −6.2 (−8.2 to −4.2) None None None High
Disability 1 214 0 1.2 (−3.8 to 6.1) None None –1 Moderate
Short-term
Pain 1 214 0 3.3 (−1.5 to 8.1) None None –1 Moderate
Disability 1 214 0 2.4 (−2.6 to 7.3) None None –1 Moderate
Safety outcomes
All time points
Adverse events (any)* 21 5153 16 1.1 (1.0 to 1.2) None None None High
Adverse events (serious)†2 635 56 1.5 (0.4 to 5.2) None –1 None Moderate
Adverse events (dropout)‡9 3283 38 1.0 (0.6 to 1.6) None None None High
Adverse events (gastro)§ 3 1167 0 2.5 (1.2 to 5.2) None None None High
Negative values favours NSAIDs.
*Number of patients reporting any adverse effect.
†Number of patients reporting any serious adverse effect (as defined by each study).
‡Number of patients withdrawn from study due to adverse effects.
§Number of patients reporting gastrointestinal adverse effects.
MC, mental component; MD, mean differences; NSAIDs, non-steroidal anti-inflammatory drugs; PC, physical component.
1274 Machado GC, etal. Ann Rheum Dis 2017;76:1269–1278. doi:10.1136/annrheumdis-2016-210597
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We provide sound evidence that NSAIDs are effective, but do
not offer clinically important benefits for spinal pain above
those attributable to placebo, given overall pooled estimated dif-
ferences were <10 points. This is crucially important because
we now know paracetamol is ineffective,
67
and opioids only
offer small benefits for spinal pain.
8
Thus, given our results and
evidence from these recent high-quality meta-analyses, it seems
that there are no analgesics with clinically important effects over
placebo for spinal pain. This is a problem, as current guidelines
for spinal pain endorse these three medicines.
5
For instance, the
National Institute for Health and Care Excellence (NICE) guid-
ance on low back pain and sciatica now recommends NSAIDs as
first analgesic option and suggests the use of opioids with para-
cetamol to treat spinal pain. In our review, even when the
effects of NSAIDs were analysed for different spinal pain strata
(ie, neck pain, acute/chronic low back pain or sciatica), only 3
of the 14 analyses revealed effects that were marginally above
our threshold for clinical relevance. The effects observed in
Figure 4 Risk ratio for safety outcome measures in placebo-controlled trials on efficacy of non-steroidal anti-inflammatory drugs (NSAIDs)
compared with placebo. Any adverse event=no. of patients reporting any adverse event; serious adverse events=no. of patients reporting any serious
adverse event (as defined by each study); GI adverse events=no. of patients reporting gastrointestinal adverse events; withdrawals=no. of patients
withdrawn from study because of adverse events. Studies are ordered chronologically within subgroups.
1275
Machado GC, etal. Ann Rheum Dis 2017;76:1269–1278. doi:10.1136/annrheumdis-2016-210597
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trials including participants with neck pain were unexpected,
particularly because these trials investigated topical NSAIDs
only. Our safety analysis revealed that NSAIDs increased the risk
of gastrointestinal adverse effects by 2.5 times compared with
placebo, although safety data were limited to trials that used
non-selective NSAIDs. However, it is established that all
NSAIDs, including COX-2 inhibitors, have been linked to
gastrointestinal harms.
15 72
Our safety results should be inter-
preted with caution given the short duration of exposure to
NSAIDs in included trials.
In summary, compared with placebo, NSAIDs do not provide
a clinically important effect on spinal pain, and six patients
must be treated with NSAIDs for one patient to achieve a clinic-
ally important benefit in the short-term. When this result is
taken together with those from recent reviews on paracetamol
and opioids, it is now clear that the three most widely used, and
guideline-recommended medicines for spinal pain do not
provide clinically important effects over placebo. There is an
urgent need to develop new analgesics for spinal pain.
Twitter Follow Gustavo Machado @gustavocmachado
Contributors All authors made substantial contributions to the study conception
and design or analysis and interpretation of data and were involved in drafting the
manuscript and approved the final version.
Funding GCM and MBP are supported by an Australian Postgraduate Award from
the Department of Education and Training of Australia. CGM is supported by a
Principal Research Fellowship from the National Health and Medical Research
Council. MLF holds a Sydney Medical Foundation Fellowship, Sydney Medical School.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
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Table 2 Secondary exploratory analyses for pain at immediate-term
Variable
Summary of findings Meta-regression
Studies Participants I
2
, % MD (95% CI) MD (95% CI) p Value
Sequence generation
Low 12 2594 65 −11.2 (−13.9 to −8.5)
Unclear 11 2623 13 −6.7 (−8.6 to −4.9) −4.2 (−7.7 to −0.8) 0.02
Allocation concealment
Low 4 680 25 −5.9 (−9.3 to −2.4)
Unclear 19 4537 60 −9.8 (−11.9 to −7.8) −3.6 (−8.4 to 1.2) 0.14
Blinding
Low 22 5037 62 −9.3 (−11.2 to −7.4)
Unclear 1 180 0 −7.1 (−14.8 to 0.6) 2.1 (−7.5 to 11.8) 0.70
Incomplete data
Low 12 2384 72 −9.0 (−12.2 to −5.8)
Unclear 6 1641 0 −7.3 (−9.3 to −5.2) 1.0 (−3.3 to 5.3) 0.65
High 5 1192 32 −11.8 (−15.1 to −8.5) −2.5 (−7.5 to 2.4) 0.31
Selective reporting
Low 18 4592 64 −9.4 (−11.4 to −7.3)
Unclear 4 545 34 −9.0 (−14.3 to −3.7) 0.7 (−5.6 to 6.9) 0.83
High 1 80 0 −6.0 (−15.0 to 3.0) 3.4 (−8.6 to 15.6) 0.59
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Low 2 300 0 −3.5 (−7.7 to 0.7)
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Discontinued drug
Yes 8 1774 0 −8.9 (−10.8 to −7.0)
No 15 3443 71 −9.3 (−12.1 to −6.5) 0.3 (−3.7 to 4.3) 0.88
COX-2, cyclo-oxygenase-2; MD, mean difference; NSAIDs, non-steroidal anti-inflammatory drugs.
1276 Machado GC, etal. Ann Rheum Dis 2017;76:1269–1278. doi:10.1136/annrheumdis-2016-210597
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meta-analysis
spinal pain: a systematic review and
Non-steroidal anti-inflammatory drugs for
Marina B Pinheiro and Manuela L Ferreira
Gustavo C Machado, Chris G Maher, Paulo H Ferreira, Richard O Day,
doi: 10.1136/annrheumdis-2016-210597
2, 2017 2017 76: 1269-1278 originally published online FebruaryAnn Rheum Dis
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