Serjeant 1985

Methods	Double‐blind, placebo‐controlled cross‐over trial, with two 14‐day treatment periods. Allocation concealment and method of randomisation was unclear.
Participants	11 males with stuttering priapism and homozygous sickle cell (SS) disease were randomised. 9 completed the trial, 1 participant defaulted after baseline and 1 participant had a painful crisis which aborted the priapism before any tablets were taken. Participants came from the sickle cell clinic of the University Hospital of the West Indies, Kingston, Jamaica.
Interventions	Stilboestrol 5 mg daily versus placebo.
Outcomes	Reduction in frequency of stuttering priapism. Return of priapism.
Notes
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	Described as double blind.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not described if outcome assessors were blinded.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	1 participant defaulted, and in two participants the attacks of stuttering priapism ceased spontaneously during the baseline observation period. There was a fourth participant who initially did not take the placebo because a painful crisis aborted the stuttering priapism prior to taking the assigned tablet. In this participant (identified as patient 9) attacks of priapism recurred 2 weeks later and data on a second baseline period were collected. The paper did not discuss an ITT analysis.
Selective reporting (reporting bias)	Low risk	No protocol available therefore outcomes reported in the results section against the methods section of the paper; no discrepancies found.
Other bias	Low risk	None identified.

BP: blood pressure ITT: intention‐to‐treat SCD: sickle cell disease