Wright 1977.

Study characteristics
Methods	Single‐center, cross‐over RCT Order of colchicine and placebo courses was determined by a randomization scheme, with a total of 59 courses (28 courses of colchicine and 31 courses of placebo) Location: USA
Participants	9 adults with a history of frequent FMF attacks Age: 18–54 years Gender: 4 women, 5 men
Interventions	Intervention: oral colchicine 3.6 mg for the first day (0.6 mg every hour for 4 hours; then every 2 hours for 4 hours), 1.2 mg for the following 2 days Control: matching placebo
Outcomes	Frequency of attacks Interval time between attacks Adverse events Outcomes measured at 10 months
Notes	The outcome data could not be distinguished between each phase.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "The order of colchicine and placebo courses was determined by a randomization scheme," and the randomization followed the method reported by Bradley Efron in 1971 named "Forcing a sequential experiment to be balanced."
Allocation concealment (selection bias)	Unclear risk	The exact method of allocation concealment was unclear.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "The tablets were bottled, coded, and dispensed by the Pharmaceutical Development Service at the National Institutes of Health."
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Whether outcome assessment was blinded was unclear.
Incomplete outcome data (attrition bias) All outcomes	High risk	5 participants completed the study and 3 dropped out Quote: "Two of these patients had been attack‐free on chronic colchicine therapy before entering the trial, and they found that having attacks again was too disruptive to their lives to complete the trial. The other patient became discouraged and dropped out after four consecutive courses failed to alter his FMF attacks (three of the courses were placebo)."
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.