Non-steroidal anti-inflammatory drugs (NSAIDs) for axial spondyloarthritis (ankylosing spondylitis and non-radiographic axial spondyloarthritis).

BACKGROUND: Axial spondyloarthritis (axSpA) comprises ankylosing spondylitis (radiographic axSpA) and non-radiographic (nr-)axSpA and is associated with psoriasis, uveitis and inflammatory bowel disease. Non-steroidal anti-inflammatory drugs (NSAIDs) are recommended as first-line drug treatment.

OBJECTIVES: To determine the benefits and harms of NSAIDs in axSpA.

SEARCH METHODS: We searched CENTRAL, MEDLINE and EMBASE to 18 June 2014.

SELECTION CRITERIA: Randomised controlled trials (RCTs) or quasi-RCTs of NSAIDs versus placebo or any comparator in adults with axSpA and observational cohort studies studying the long term effect (≥ six months) of NSAIDs on radiographic progression or adverse events (AEs). The main comparions were traditional or COX-2 NSAIDs versus placebo. The major outcomes were pain, Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), Bath Ankylosing Spondylitis Metrology Index (BASMI), radiographic progression, number of withdrawals due to AEs and number of serious AEs

DATA COLLECTION AND ANALYSIS: Two review authors independently selected trials for inclusion, assessed the risk of bias, extracted data and assessed the quality of evidence for major outcomes using GRADE.

MAIN RESULTS: We included 39 studies (35 RCTs, two quasi-RCTs and two cohort studies); and 29 RCTs and two quasi-RCTs (n = 4356) in quantitative analyses for the comparisons: traditional NSAIDs versus placebo, cyclo-oxygenase-2 (COX-2) versus placebo, COX-2 versus traditional NSAIDs, NSAIDs versus NSAIDs, naproxen versus other NSAIDs, low versus high dose. Most trials were at unclear risk of selection bias (n = 29), although blinding of participants and personnel was adequate in 24 trials. Twenty-five trials had low risk of attrition bias and 29 trials had low risk of reporting bias. Risk of bias in both cohort studies was high for study participation, and low or unclear for all other criteria. No trials in the meta-analyses assessed patients with nr-axSpA.Traditional NSAIDs were more beneficial than placebo at six weeks. High quality evidence (four trials, N=850) indicates better pain relief with NSAIDs (pain in control group ranged from 57 to 64 on a 100mm visual analogue scale (VAS) and was 16.5 points lower in the NSAID group (95% confidence interval (CI) -20.8 to -12.2), lower scores indicate less pain, NNT 4 (3 to 6)); moderate quality evidence (one trial, n = 190) indicates improved disease activity with NSAIDs (BASDAI in control group was 54.7 on a 100-point scale and was 17.5 points lower in the NSAID group, 95% CI -23.1 to -11.8), lower scores indicate less disease activity, NNT 3 (2 to 4)); and high quality evidence (two trials, n = 356) indicates improved function with NSAIDs (BASFI in control group was 50.0 on a 100-point scale and was 9.1 points lower in the NSAID group (95% CI -13.0 to -5.1), lower scores indicate better functioning, NNT 5 (3 to 8)). High (five trials, n = 1165) and moderate (three trials, n = 671) quality evidence (downgraded due to potential imprecision) indicates that withdrawals due to AEs and number of serious AEs did not differ significantly between placebo (52/1000 and 2/1000) and NSAID (39/1000 and 3/1000) groups after 12 weeks (risk ratio (RR) 0.75, 95% CI 0.46 to 1.21; and RR 1.69, 95% CI 0.36 to 7.97, respectively). BASMI and radiographic progression were not reported.COX-2 NSAIDS were also more efficacious than placebo at six weeks. High quality evidence (two trials, n = 349) indicates better pain relief with COX-2 (pain in control group was 64 points and was 21.7 points lower in the COX-2 group (95% CI -35.9 to -7.4), NNT 3 (2 to 24)); moderate quality evidence (one trial, n = 193) indicates improved disease activity with COX-2 (BASDAI in control groups was 54.7 points and was 22 points lower in the COX-2 group (95% CI -27.4 to -16.6), NNT 2 (1 to 3)); and high quality evidence (two trials, n = 349) showed improved function with COX-2 (BASFI in control group was 50.0 points and was 13.4 points lower in the COX-2 group (95% CI -17.4 to -9.5), NNT 3 (2 to 4)). Low and moderate quality evidence (three trials, n = 669) (downgraded due to potential imprecision and heterogeneity) indicates that withdrawals due to AEs and number of serious AEs did not differ significantly between placebo (11/1000 and 2/1000) and COX-2 (24/1000 and 2/1000) groups after 12 weeks (RR 2.14, 95% CI 0.36 to 12.56; and RR 0.92, 95% CI 0.14 to 6.21, respectively). BASMI and radiographic progression were not reported.There were no significant differences in benefits (pain on VAS: MD -2.62, 95% CI -10.99 to 5.75; three trials, n = 669) or harms (withdrawals due to AEs: RR 1.04, 95% CI 0.60 to 1.82; four trials, n = 995) between NSAID classes. While indomethacin use resulted in significantly more AEs (RR 1.25, 95% CI 1.06 to 1.48; 11 studies, n = 1135), and neurological AEs (RR 2.34, 95% CI 1.32 to 4.14; nine trials, n = 963) than other NSAIDs, these findings were not robust to sensitivity analyses. We found no important differences in harms between naproxen and other NSAIDs (three trials, n = 646), although other NSAIDs appeared more effective for relieving pain (MD 6.80, 95% CI 3.72 to 9.88; two trials, n = 232). We found no clear dose-response effect on benefits or harms (five studies, n = 1136). Single studies suggest NSAIDs may be effective in retarding radiographic progression, especially in certain subgroups of patients, e.g. patients with high CRP, and that this may be best achieved by continuous rather than on-demand use of NSAIDs.

AUTHORS' CONCLUSIONS: High to moderate quality evidence indicates that both traditional and COX-2 NSAIDs are efficacious for treating axSpA, and moderate to low quality evidence indicates harms may not differ from placebo in the short term. Various NSAIDs are equally effective. Continuous NSAID use may reduce radiographic spinal progression, but this requires confirmation.