Goldstein 1974.

Study characteristics
Methods	Single‐center, cross‐over RCT 90 days for each course then switch to alternative; no reported washout period Location: USA
Participants	15 people with FMF and a high frequency of attacks (≥ 1 attack per month for ≥ 1 year), absence of amyloidosis or concurrent disease, without chronic steroid or narcotic usage and no evidence of pregnancy Age: 16–53 years Gender: 8 females, 2 males (participants completed study)
Interventions	Intervention: colchicine 0.6 mg orally 3 times daily for 90 days Control: matching placebo No washout period or assessment of carryover effect was reported
Outcomes	Number of participants experiencing an attack Frequency of attacks Outcomes measured at 3 and 6 months
Notes	The outcome data, except "number of participants experiencing an attack," could not be distinguished between phase I and II of the cross‐over study.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not described.
Allocation concealment (selection bias)	Unclear risk	Not described.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "Double‐blind study". "Neither of the physicians involved in the patients' care was aware of the drug being administered". "A drug crossover was done by the pharmacist after 90 days of treatment, without the knowledge of the patients."
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Double‐blind; however, we do not know whether outcome assessment was blinded.
Incomplete outcome data (attrition bias) All outcomes	High risk	Quote: "Ten of the 15 patients completed the 180‐day study. Five patients had to be eliminated from the study for failure to take the medication regularly or meet the follow‐up requirements, or both." No indication if the 5 participants who dropped out received 1 of the interventions or both, and no ITT analyses were reported.
Selective reporting (reporting bias)	Unclear risk	Protocol could not be reviewed, moreover the methods section did not predefine outcome measurements.
Other bias	High risk	Differences of FMF severity between groups were not described.