Mena 1977.

Methods	Design: RCT Number of centres: NA Treatment duration: 6 weeks Flare design: Yes Wash‐out period: No Time point of assessments: BL, 2, 4, 6 weeks
Participants	Inclusion criteria: 1. At least two Rome clinical criteria of the disease; 2. Abnormal or ankylosed sacroiliac joints by radiographic criteria; 3. Suffering an exacerbation of their disease, defined as a clear increase in spinal or sacroiliac pain and one or more of the following: a) muscle spasm in the back, b) decreased range of motion of some part of the spine, c) elevation of the ESR. Exclusion criteria: 1. Age below 19 years; 2. Involvement of more than two peripheral joints not including the shoulders or hips; 3. Probability of pregnancy during the trial; 4. Hypersensitivity to the experimental drugs; 5. Other rheumatoid variants, positive rheumatoid factor or serious concomitant diseases. Classification: Rome criteria Flurbiprofen (150 to 200 mg): Number of participants: 12 Number of completers: 9 Age: NA Male (%): 75 Symptom duration: NA Disease duration: NA HLA‐B27 positive (%): "HLA‐B27 antigen was tested in 8 patients and only one was negative" Phenylbutazone (300 to 400 mg): Number of participants: 15 Number of completers: 13 Age: NA Male (%): 80 Symptom duration: NA Disease duration: NA HLA‐B27 positive (%): "HLA‐B27 antigen was tested in 8 patients and only one was negative"
Interventions	Flurbiprofen (150 to 200 mg) vs Phenylbutazone (300 to 400 mg) Co‐medication: Co‐medication was allowed, but the use of any other analgesia or anti‐inflammatory drug was discouraged.
Outcomes	Extracted outcomes: 1. Pain on Likert scale (BL, mean change after 6 weeks) (scale 0 to 4, higher is worse) Flurbiprofen 150 to 200 mg: 2.3 (N = 12), ‐0.8 (N = 9) (P < 0.05 versus BL) Phenylbutazone 300 to 400 mg: 1.9 (N = 15), ‐0.7 (N = 13) (P < 0.05 versus BL) 2. Withdrawals due to adverse events 3. Duration of morning stiffness (BL, mean change after 6 weeks) (in hours, higher is worse) Flurbiprofen 150 to 200 mg: 4.6 (N = 12), ‐4.3 (N = 9) (P = not significant versus BL) Phenylbutazone 300 to 400 mg: 1.2 (N = 15), +0.5 (N = 13) (P = not significant versus BL) 4. ESR (BL, mean change after 6 weeks) (in mm/hr, higher is worse) Flurbiprofen 150 to 200 mg: 24.0 (N = 12), +5.6 (N = 9) (P = not significant versus BL) Phenylbutazone 300 to 400 mg: 28.0 (N = 15), ‐6.7 (N = 13) (P < 0.05 versus BL) 5. Chest expansion (BL, mean change after 6 weeks) (in cm, higher is better) Flurbiprofen 150 to 200 mg: 2.5 (N = 12), +0.5 (N = 9) (P < 0.05 versus BL) Phenylbutazone 300 to 400 mg: 3.2 (N = 15), +0.1 (N = 13) (P = not significant versus BL) 6. Occiput‐to‐wall distance (BL, mean change after 6 weeks) (in cm, higher is worse) Flurbiprofen 150 to 200 mg: 7.6 (N = 12), ‐1.1 (N = 9) (P < 0.05 versus BL) Phenylbutazone 300 to 400 mg: 6.6 (N = 15), ‐1.4 (N = 13) (P < 0.02 versus BL) 7. Schober's test (BL, mean change after 6 weeks) (in cm, higher is better) Flurbiprofen 150 to 200 mg: 12.3 (N = 12), +0.0 (N = 9) (P = not significant versus BL) Phenylbutazone 300 to 400 mg: 12.6 (N = 15), +0.5 (N = 13) (P < 0.05 versus BL) 8. Number of any adverse events 9. 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, duration of morning stiffness, ESR, occiput‐to‐wall distance, Schober's test. Available results are described in this table. Funding source: The Upjohn Company provided a grant to support this study.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"Twelve patients were randomly assigned to a flurbiprofen group and 15 to a phenylbutazone group." No 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	Low risk	"The drugs were available in a blister package. Each blister contained one 50 mg tablet of flurbiprofen or one 100 mg tablet of phenylbutazone and a placebo tablet identical to the other drug."
Blinding of outcome assessment (detection bias) All outcomes	Low risk	"The contents of the tablets were not known to the patient or the investigator."
Incomplete outcome data (attrition bias) All outcomes	Low risk	Attrition is equal and low (< 25%) in both groups.
Selective reporting (reporting bias)	Low risk	All outcomes stated in the methods were reported.
Other bias	Low risk	No other bias was detected.