Calin 1979.

Methods	Design: CCT Number of centres: NA Treatment duration: 6 months Flare design: Yes Wash‐out period: Yes Time point of assessments: "on 8 occasions during the six‐month period"
Participants	Inclusion criteria: HLA‐B27 positive, and fulfilling the New York criteria. Exclusion criteria: NA Classification: New York criteria Indomethacin (75 to 150 mg): Number of participants: 15 Number of completers: 15 Age (mean): 44.6 Male (%): 80 Symptom duration: NA Disease duration: NA HLA‐B27 positive (%): 100 Sulindac (200 to 400 mg): Number of participants: 15 Number of completers: 12 Age (mean): 32.7 Male (%): 80 Symptom duration: NA Disease duration: NA HLA‐B27 positive (%): 100
Interventions	Indomethacin (75 to 150 mg) vs Sulindac (200 to 400 mg) Co‐medication: NA
Outcomes	Extracted outcomes: 1. Withdrawals due to adverse events 2. Lateral spinal flexion (BL, post‐treatment after 6 months) (in cm, higher is better) Indomethacin 75 to 150 mg: 2.0 (N = 15), 3.8 (N = 15) Sulindac 200 to 400 mg: 3.1 (N = 15), 5.5 (N = 14) 3. Chest expansion (BL, post‐treatment after 6 months) (in cm, higher is better) Indomethacin 75 to 150 mg: 2.7 (N = 15), 3.7 (N = 15) Sulindac 200 to 400 mg: 3.1 (N = 15), 4.5 (N = 14) 4. Intermalleolar distance (BL, post‐treatment after 6 months) (in cm, higher is better) Indomethacin 75 to 150 mg: 89 (N = 15), 103 (N = 15) Sulindac 200 to 400 mg: 90 (N = 15), 114 (N = 14) 5. Schober's test (BL, post‐treatment after 6 months) (in cm, higher is better) Indomethacin 75 to 150 mg: 2.6 (N = 15), 3.9 (N = 15) Sulindac 200 to 400 mg: 2.8 (N = 15), 5.2 (N = 14) 6. Number of any adverse events
Notes	Outcomes that were not included in the meta‐analysis, because no measure of variance (SD, SE or CI) was reported for these outcomes: lateral spinal flexion, chest expansion, intermalleolar distance, Schober's test. Available results are described in this table. For the outcome lateral spinal flexion, "left lateral spinal flexion" was extracted ("right lateral spinal flexion" was also available, there was no difference between left and right). Funding source: Not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	No comment is made by authors that patients were randomised.
Allocation concealment (selection bias)	High risk	No comment is made by the authors that patients were randomised.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	"…plus dummy sulindac tablets…plus dummy indomethacin tablets". Participants appear to have been blinded to treatment allocation.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	"double‐blind". Probably done, but no further information was provided on blinding of outcome assessors.
Incomplete outcome data (attrition bias) All outcomes	Low risk	"The three dropouts were unavailable for follow‐up for reasons not related to tolerance or efficacy." Although uneven number of dropouts in treatment groups (0 vs 3), there appears to be a low risk of attrition bias.
Selective reporting (reporting bias)	High risk	The following pre‐specified outcomes were not reported: pain during night and day, duration of morning stiffness, fatigue, global score by patient and physician, daily functioning, loss of lordosis and occiput‐to‐wall‐distance.
Other bias	Unclear risk	Baseline imbalance and administration of co‐medication cannot be ruled out.