Solomon 1988.

Methods	Setting: Eastern Clinic of the Baltimore City Health Department, MD, US Enrolment: index patients were enrolled between May 1984 and January 1985 Follow up: index patients returned to clinic 14 days after treatment
Participants	902 index patients, with a positive Gram stain for gonorrhoea, were randomised Inclusion criteria Male with positive Gram stain for gonococci Exclusion criteria Not criteria specified
Interventions	All index patients received a DIS contact tracing interview and treatment from a nurse. At the time of test of cure examination an 18‐item, oral test to assess the videotape's impact on knowledge and beliefs of the index patient was performed Patient referral and videotape (n = 456) Index patient was interviewed by DIS to get the contact details of their partners, and was given contact cards and was invited to view a video‐tape promoting PN Simple patient referral (n = 446) Index patient was interviewed by DIS to get the contact details of their partners, and was given contact cards
Outcomes	Number of index patients returning for a "test of cure" evaluation (clinic records) Number of partners presented for care (contact cards returned) Knowledge of the index patient (18‐item, true‐false, oral test) Time taken until partner presented at clinic (clinical records)
Notes	Ethical approval details not given
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No details were given except that the research assistant assigned patients at random to group 1 (watching the videotape) and group 2 (not watching the videotape)
Allocation concealment (selection bias)	Unclear risk	No mention of allocation concealment
Incomplete outcome data (attrition bias) All outcomes	Low risk	Outcome data available for all partners of index patients
Selective reporting (reporting bias)	Low risk	Outcomes reported in methods section were reported in results section. Trial registries not searched
Other bias	Unclear risk	Baseline comparability unclear
Blinding of participants and personnel (performance bias) All outcomes	High risk	Participant and personnel not blinded
Blinding of outcome assessment (detection bias) All outcomes	Low risk	If a partner came to the clinic with a referral card, a clerk noted the participant number on registration. The clerk was blinded to what experimental study the colour coding belonged to. The research assistant, who performed the oral test at the test of cure evaluation, was blinded to whether participant saw the video tape or not