Ebner 1983.

Methods	Design: RCT Number of centres: NA Treatment duration: 8 weeks Flare design: No Wash‐out period: Yes (1 week) Time point of assessments: BL, 1, 2, 3, 4, 6, 8 weeks
Participants	Inclusion criteria: 1. Definite AS, defined as having 4 of the 5 following clinical criteria or one of these criteria and characteristic X‐ray findings: a) pain and stiffness in lumbar and dorsal lumbar junction existing for more than 3 months with no improvement at rest, b) pain and stiffness in thoracic region for more than 3 months, c) restricted mobility in lumbar vertebral column, d) restricted chest expansion, and e) clinical history or objective symptoms of an iritis sequels; 2. Active disease (marked pain in the vertebral column and at least one of the following: increased muscular tension in the back, restricted range of motion in any part of the vertebral column, an accelerated ESR). Exclusion criteria: 1. Treatment with corticosteroids or an experimental anti‐inflammatory drug within 4 weeks of onset of the study; 2. Treatment with gold or anti‐malarials within 3 months of onset of the study; 3. Concomitant treatment with anticoagulants; 4. Severe cardiorespiratory insufficiency; 5. Laboratory findings indicating hepatic or renal disease; 6. Signs of significant disease of the gastrointestinal tract; 7. Clinically significant eye disease, bone marrow suppression or vasculitis; 8. A history of severe allergic reactions either to indomethacin or to derivatives of anthralinic acid; 9. Hemoglobin < 10, hematocrit < 30, WBC < 4500/mm³. Classification: NA Meclofenamate sodium (300 mg): Number of participants: 49 Number of completers: 39 Age (median): 35 (range 16 to 67) Male (%): 90 Symptom duration: NA Disease duration (median): 8 (range 0.5 to 28) years HLA‐B27 positive (%): NA Indomethacin (150 mg): Number of participants: 49 Number of completers: 41 Age (median): 34 (range 20 to 70) Male (%): 83 Symptom duration: NA Disease duration (median): 7 (range 0.5 to 50) years HLA‐B27 positive (%): NA
Interventions	Meclofenamate sodium (300 mg) vs Indomethacin (150 mg) Co‐medication: Patients were requested to avoid taking any other analgesic or anti‐inflammatory drugs during the study. The physician could prescribe a muscle relaxant, if this was necessary.
Outcomes	Extracted outcomes: 1. Pain on Likert scale (BL, percentage change from BL after treatment) (scale 0 to 4, higher is worse) Meclofenamate sodium 300 mg: 2.27 (N = 48), ‐53.3% (N = 48) Indomethacin 150 mg: 2.25 (N = 46), ‐58.7% (N = 46) (P = not significant between groups) 2. Withdrawals due to adverse events 3. Patient's global assessment of disease activity (BL, percentage change from BL after treatment) (scale 0 to 5, higher is worse) Meclofenamate sodium 300 mg: 2.58 (N = 48), ‐32.2% (N = 48) Indomethacin 150 mg: 2.57 (N = 46), ‐41.6% (N = 46) (P = not significant between groups) 4. Duration of morning stiffness (BL, percentage change from BL after treatment) (median in minutes, higher is worse) Meclofenamate sodium 300 mg: 25 (N = 48), ‐60.0% (N = 48) (P < 0.01 versus baseline) Indomethacin 150 mg: 30 (N = 46), ‐70.0% (N = 46) (P < 0.01 versus BL, P = not significant between groups) 5. Chest expansion (BL, percentage change from BL after treatment) (in cm, higher is better) Meclofenamate sodium 300 mg: 4.39 (N = 48), +22.1% (N = 48) (P < 0.01 versus BL) Indomethacin 150 mg: 4.13 (N = 46), +29.1% (N = 46) (P < 0.01 versus BL, P = not significant between groups) 6. Schober's test (BL, percentage change from BL after treatment) (in cm, higher is better) Meclofenamate sodium 300 mg: 2.23 (N = 48), +52.5% (N = 48) (P < 0.01 versus BL) Indomethacin 150 mg: 2.03 (N = 46), +51.2% (N = 46) (P < 0.01 versus BL, P = not significant between groups) 7. Number of any adverse events 8. Number of adverse events per organ system
Notes	Outcomes that were not included in the meta‐analysis, because no measure of variance (SD, SE or CI) was reported for these outcomes: pain on Likert scale, patient's global assessment of disease activity, duration of morning stiffness, chest expansion, Schober's test. Available results are described in this table. Funding source: Not reported.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"All patients in each participating center were randomly assigned to treatment with either…" Probably done, but no further information was provided on sequence generation.
Allocation concealment (selection bias)	Unclear risk	No information provided on allocation concealment.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	"Following a single‐blind baseline period on placebo, patients received either meclofenamate sodium or indometacin for 8 weeks under parallel double‐blind conditions." Comment: Probably done, but no further information was provided on blinding of participants.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	"double‐blind conditions" Probably done, but no further information was provided on blinding of outcome assessors.
Incomplete outcome data (attrition bias) All outcomes	Low risk	"Patients were evaluated for efficacy if they received medication for more than one week and if premedication had been terminated as required in the protocol." "The rate of patients who withdrew from the study was similar in the 2 treatment groups."
Selective reporting (reporting bias)	Low risk	All pre‐specified outcomes according to the methods section, are reported in the results section.
Other bias	Low risk	No other bias detected.