Perkins 1956.

Methods	Allocation of tablets labelled A or B according to random list. It was not clear whether 1 or both eyes were included
Participants	Uveitis participants (n = 164) enrolled at first attendance at uveitis clinic, London, UK. Subgroup analyses presented for participants with a positive toxoplasma antibody dye test and posterior uveitis (n = 29). Varying age group from (1 to 19) years to 60+
Interventions	Pyrimethamine (Daraprim) 25 mg daily for 4 weeks versus inert tablet
Outcomes	No improvement versus improvement in signs of intraocular inflammation at 4 weeks (in 29 people with posterior uveitis and toxoplasma antibodies). Adverse events: depressed leucocyte count (for all uveitis participants only; n = 113 treated and 70 untreated). Ophthalmic assessor unaware of treatment allocation and usually unaware of dye test result. Proportion receiving pyrimethamine (Daraprim) in dye test positive versus negative groups differs, raising the possibility of breaches of allocation concealment
Notes	Date study conducted: Not reported. Funding source: Not reported. Declaration of interest: Not reported. Trial registration: Not reported.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	“...distributed according to a random list.”
Allocation concealment (selection bias)	Unclear risk	No statement relevant to allocation concealment
Blinding of participants and personnel (performance bias) All outcomes	Low risk	“The clinician in charge of the patient does not know which of the two tablets the patient has received.”
Blinding of outcome assessment (detection bias) All outcomes	Low risk	“The person making the assessment did not know whether the patient had received Daraprim or the inert tablets.”
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	“Some patients had to be excluded because of difficulty in follow‐up or interruption of treatment by intercurrent illness.” These participants do not appear to have been counted in the results
Selective reporting (reporting bias)	Low risk	The only outcome report was improvement in symptoms