Wilson 2009.

Methods	Setting: 2 STI clinics in Brooklyn, NY, US. One was a non‐Department of Health clinic for STI and the other a Department of Health STI clinic Enrolment: index patients enrolled between January 2002 and December 2004 Follow‐up: index patient was interviewed at 1 and 6 months after baseline. Testing of index patient for re‐infection with Neisseria gonorrhoeae and Chlamydia trachomatis at 6 months after baseline
Participants	600 index patients (245 women and 355 men), with chlamydia or gonorrhoea, were randomised Inclusion criteria Microbiological confirmed diagnosis of C. trachomatis or N. gonorrhoeae within the previous 2 weeks Aged 18 years or older Able to complete an interview in English or Spanish Sexually active in the 2 months prior to enrolment Residing in New York City area for the evaluation period Exclusion criteria No criteria specified
Interventions	Patient referral with 2 counselling sessions (4 weeks apart) (n = 304) The first session was designed to occur in the clinic at the time of STI diagnosis. This was a one‐on‐one counselling session with health educator discussing risk behaviour, identification of eligible sexual partners, development of a notification plan, role‐play exercises and completion of a signed behavioural contract to notify partners. Index patients received support material including written pamphlet on PN and referral slips to give to partner with information on where to access free confidential STI testing and treatment. The second session was designed to take place by telephone or in person, 4 weeks after initial session. Review of progress and any remaining barriers to notification process were discussed Simple patient referral (n = 296) Index patient met with health educator at the time of STI diagnosis. The health educator asked the index patient if there were any questions related to the clinic visit, diagnosis, treatment or prevention. A brief discussion period followed. Index patient was given referral slips to give to partner with information on where to access free confidential STI testing and treatment
Outcomes	Primary outcome PN (self report by index patient during interview 1 month after baseline) Harms ‐ arguments or instances of physical violence (self report by index patient during interview 1 month after baseline) Secondary outcomes Re‐infection of index patient at 6 months (urine test) Sexual behavioural changes over last 90 days ‐ number of partners, type of intercourse, condom use (self report by index patient during interview 6 months after baseline)
Notes	Ethical approval by institutional review board at participating sites and at the CDC Author was contacted and they were unable to account for reasons for unequal distribution of STIs at baseline Authors could not provide exact numbers of partners for outcomes. Distribution of harms between 2 groups and detail on protocol obtained from authors. The randomisation process was implemented throughout recruitment as described in the study
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Stratified block randomisation algorithm, with stratifications by site of recruitment and gender within site. Computerised random number generator
Allocation concealment (selection bias)	Unclear risk	The principal investigator pre‐assigned sequential study identification numbers according to the random number generated sequence. Participants were assigned study identification numbers sequentially as they enrolled in the study. There was no explicit mention of safeguards to concealment such as opaque sealed envelopes, or signing consent before randomisation
Incomplete outcome data (attrition bias) All outcomes	Low risk	263/296 (88%) in simple patient referral group completed 1 and 6 month after baseline interview and had a valid urine test result. In the patient referral group with 2 counselling sessions, 253/304(83%) completed 1 and 6 month after baseline and had a valid urine test result
Selective reporting (reporting bias)	High risk	Protocol obtained from trial registries Outcome in protocol: Primary outcomes in protocol was PN and re‐infection of index patient at 6 months Outcome in actual study: Primary outcomes in actual study are PN and harms In the protocol, 3 intervention arms were described, in the actual study only 2 arms were reported
Other bias	Low risk	No other bias identified
Blinding of participants and personnel (performance bias) All outcomes	High risk	No blinding of participant or personnel
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Blinding of study interviewers was performed. The study interviewers were not employees of the study clinics neither did they engage in any health education activities. Study interviewers were not informed of participant group assignment. Laboratory personnel were blinded

CDC: Centers for Disease Control and Prevention; DIS: disease intervention specialist; DNA: deoxyribonucleic acid; EPT: expedited partner therapy; FPC: family planning clinic; GUM: genitourinary medicine; HIV: human immunodeficiency virus; ITT: intention to treat; NGU: non‐gonococcal urethritis; PCR: polymerase chain reaction; PID: pelvic inflammatory disease; PN: partner notification; RNA: ribonucleic acid; STI: sexually transmitted infection; WHO: World Health Organization.