The quality of evidence is downgraded by study limitations (unclear allocation concealment), by inconsistency (variability in results), and by imprecise results (wide confidence intervals).
A Cochrane review [Abstract] 1 included 11 studies with a total of 895 subjects comparing sulfasalazine with placebo. The age ranged from 26.9 to 45.7 and the duration of disease ranged from 3.8 to 21.9 years. None of the included studies assessed bath ankylosing spondylitis disease activity index (BASDAI), bath ankylosing spondylitis function index (BASFI), bath ankylosing spondylitis metrology index (BASMI), or radiographic progression. Different parameters were used to assess pain. Results for back pain measured on a 0 to 100 mm visual analogue scale (VAS) are shown in table T1. Pooled data showed that sulfasalazine did significantly ease morning stiffness measure on a 0 to 100 mm VAS (MD -13.89, 95% CI -22.54 to -5.24; 2 studies, n=108) and reduce erythrocyte sedimentation rate (MD -4.79 mm/hr, 95% CI -8.80 to -0.78; 8 studies, n=560), even though the slight difference does not have much clinical significance. Only two studies analyzed the effect of sulfasalazine on peripheral arthritis: one study presented data of the subgroup with peripheral arthritis (N = 15) and found no statistically significant difference between the sulfasalazine and placebo group. The other study separately analyzed the results of participants with peripheral arthritis (N = 77) and found more peripheral responses in the sulfasalazine group than in the placebo group.
Significantly higher rate of withdrawals due to adverse effects was found in the sulfasalazine group (table T1). The most frequent side effects with sulfasalazine were nausea, heartburn, epigastric distress, skin reactions, lightheadedness, and headache. A serious adverse reaction was reported in one patient taking sulfasalazine.
| Outcome | Participants (studies) | Assumed risk - placebo | Corresponding risk - sulfasalazine (95% CI) | Relative effect (95% CI) |
|---|---|---|---|---|
| 1) 100 mm visual analogue scale, 0 = no pain, 100 = severe; 2) median follow-up 26 weeks; 3) mean follow-up 36 weeks | ||||
| Back pain1,2 | 454 (6 studies) | Mean back pain in the control groups was49.5 mm | 2.96 mm lower(6.33 lower to 0.41 higher) | - |
| Withdrawals due to adverse events2 | 895 (11 studies) | 94 per 1000 | 134 per 1000(98 to 182) | RR 1.43 (1.04 to 1.94) |
| Serious adverse events3 | 264 (1 study) | 0 per 1000 | 1 per 1000 (0 to 0) | Peto OR 7.5 (0.15 to 378.16) |
Primary/Secondary Keywords