Ettinger 1984.

Methods	Randomized double‐blind placebo‐controlled cross‐over study
Participants	25 patients with Raynaud's Mean age 36.7 ± 2.5 years, range 21 to 60 Mean disease duration 9.5 ± 1.4 years 6 primary Raynaud's phenomenon 16 secondary Raynaud's phenomenon
Interventions	Nifedipine Dazoxiben Placebo
Outcomes	Participant diary used to record Raynaud's phenomenon with number, duration, severity, pain, overall response to treatment, and side effects
Notes	Intervention with 3 arms; number of participants with placebo divided by 2 to avoid double‐counting
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Information insufficient for judgement of low or high risk of bias
Allocation concealment (selection bias)	Unclear risk	Information insufficient for judgement of low or high risk of bias
Blinding of participants and personnel (performance bias) All outcomes	Low risk	"Double‐blind" study
Blinding of outcome assessment (detection bias) All outcomes	Low risk	"Double‐blind" study
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	19/25 completing the study
Selective reporting (reporting bias)	Low risk	All outcome data reported
Other bias	Unclear risk	Information insufficient for judgement of low or high risk of bias