| Methods |
Double‐blind placebo‐controlled randomized trial
Cross‐over design |
| Participants |
N = 26 patients ‐ 21 women, 5 men
Median age 38 years, range 22 to 61
Patients selected from files of general practitioners in hospital area
All with typical Raynaud's phenomenon
Median duration of symptoms 14 years
12 tobacco users
5 dropouts |
| Interventions |
Cross‐over trial comprising 2 periods of treatment each for 2 weeks
Participants randomly allocated to receive either nifedipine or placebo and crossed over for the second treatment period
Total study duration 4 weeks |
| Outcomes |
Daily record of number of attacks
Most severe attack graded
Days compared with participant expectations
Subjective overall evaluation at completion of treatment |
| Notes |
|
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Unclear risk |
Evidence insufficient for judgement of risk |
| Allocation concealment (selection bias) |
Unclear risk |
Evidence insufficient for judgement of risk |
| Blinding of participants and personnel (performance bias)
All outcomes |
Low risk |
"Double‐blind" ‐ "randomly allocated to receive either 20mg nifedipine or placebo in equivalent numbers" |
| Blinding of outcome assessment (detection bias)
All outcomes |
Low risk |
Participant‐recorded number and severity of attacks and evaluation of treatment efficacy |
| Incomplete outcome data (attrition bias)
All outcomes |
High risk |
5 lost to follow‐up (4 from treatment group for side effects) |
| Selective reporting (reporting bias) |
Unclear risk |
None detected |
| Other bias |
Unclear risk |
No mention of a washout period between cross‐over phases |
