Andersen 1998.

Methods	Setting: general practices in Aarhus, Denmark Enrolment: women who tested positive for Chlamydia trachomatis were randomised ‐ no specific date given Follow‐up: no follow‐up was recorded
Participants	96 women with C. trachomatis were randomised Inclusion criteria Women C. trachomatis positive Exclusion criteria Not specified
Interventions	Patient referral with home sampling (n = 45) Index patients were given a questionnaire about numbers of sexual partners. Index patients were given an envelope with a urine sample home test kit for each partner. The sample was to be sent by the partner to the study laboratory in the provided prepaid envelope Patient referral with office sampling (n = 51) Not stated if index patients completed questionnaire. Index patients were given an envelope containing a contact slip and a request to partner to visit his doctor to request sampling by urethral swab. The doctor was to send a sample in a prepaid envelope to the study laboratory
Outcomes	Partners contacted (partners receiving a urine sample test kit or contact slip delivered by index patient) Partners tested (review of laboratory records) Partners testing positive for chlamydia (review of laboratory records) Time until testing (clinical records
Notes	It is not known how many of the partners who tested positive were treated Ethical approval was obtained but no details given Unclear whether consent was obtained
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Used date of birth "Ninety six women with C trachomatis infection seen in general practices in Aarhus County, Denmark, were randomly divided according to their date of birth into an intervention group (45 patients) and a control group (51 patients)"
Allocation concealment (selection bias)	Unclear risk	Envelopes used for both groups but not stated if they appeared identical. Envelopes for the intervention group contained a 10 mL container that may be palpable
Incomplete outcome data (attrition bias) All outcomes	Low risk	Test outcome for each partner of every index patient who was randomised was available
Selective reporting (reporting bias)	Low risk	Outcomes reported in methods section were reported in results section. Trial registries were not searched
Other bias	Unclear risk	No comparison of baseline characteristics between study arms
Blinding of participants and personnel (performance bias) All outcomes	High risk	Participants and personnel were not blinded
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Samples were sent to the laboratory in provided envelopes. It is not stated whether the laboratory personnel knew which procedure was allocated to which group. For urine sample a PCR was performed, for urethral swab enzyme immune assay and if inconclusive a PCR to confirm