Methods	DESIGN: Single-centre RCT.
	LENGTH OF FOLLOW-UP: 6 and 12 months.
	DATA ANALYSIS: Stated that an intention to treat (ITT) protocol was used in which participants were analysed in their originally assigned trial conditions irrespective of the number of sessions attended. However, this definition of ITT does not explicitly include attrition and no explanation was provided as to how missing data were included in the analysis for outcomes reported at 6 months and 12 months follow up (analyses over the whole 12-month follow up period could account for missing data as they were based on more flexible general estimating equations)
	ATTRITION RATE:
	Completed 6 month follow up: Group 1 = 226/251 (90%); Group 2 = 243/271 (89. 7%); difference between groups: P = 0.89
	Completed 12 month follow up: Group 1 = 219/251 (87.3%); Group 2 = 241/271 (88. 9%); difference between groups: P = 0.56
	UNIT OF DATA ANALYSIS: Individuals, as randomised.
	SAMPLE SIZE CALCULATION: Based on previous research which identified approximately 25% consistent condom use, the authors projected a clinically meaningful effect size of a 50% increase in consistent condom use in Group 1. Estimating 20% attrition over the 12-month follow up period and setting the type I error rate at 0.05 for a 2-tailed test with power=0.80 required enrolling 250 participants per study group to detect the specified effect size. For STI incidence, the authors stated that sample size and statistical power were limited for each assessment interval, so STI incidence was determined only for the entire 12 month follow up period
	EQUIVALENT STUDY GROUPS AT BASELINE: Stated that at baseline significant differences were observed for several variables associated with HIV-related sexual behaviours and were included as covariates in subsequent (=adjusted) analyses; no differences were observed for socio-demographic characteristics, the primary outcome measure, or other outcome measures
	PROCESS EVALUATION: Not reported in detail, but stated that nearly 98% of activities in each study condition were implemented with fidelity, 95.2% of participants completed all intervention sessions and 94.5% of participants completed all general health promotion sessions. Participants’ mean±SD ratings of session content and delivery, recorded on a 5-point scale, were comparably high for both Group 1 (4.82±0.11) and Group 2 (4.76±0.09)
Participants	NUMBER RANDOMISED: 522
	AGE, mean (SD): Group 1 = 15.99 (1.25) years; Group 2 = 15.97 (1.21) years
	SOCIO-ECONOMIC STATUS (*indicates an error in the % value reported in the primary publication; the correct value is given here):
	Did not complete 10th grade, n (%): Group 1 = 115 (45.8); Group 2 = 132 (48.7)
	Recipient of public assistance, n (%): Group 1 = 45 (17.9); Group 2 = 50 (18.5)
	Living in single-parent home, n (%): Group 1 = 146 (58.2*); Group 2 = 162 (59.8*)
	Living with someone other than a parent, n (%): Group 1 = 54 (21.5); Group 2 = 47 (17.3)
	Employed, n (%): Group 1 = 40 (15.9*); Group 2 = 53 (19.6*).
	Has children, n (%): Group 1: 60 (23.9); 63 (23.2).
	ETHINCITY/RACE: All African American.
	LOCATION: USA; Birmingham, Alabama, area.
	PREVIOUS STI (* indicates a slight difference in the reported and correct calculated percentages; the correct value is given here):
	Chlamydia, n (%): Group 1 = 48 (19.1*); Group 2 = 43 (15.9).
	Gonorrhoea, n (%): Group 1 = 14 (5.6); Group 2=13 (4.8).
	Trichomonas, n (%): Group 1 = 33 (13.1*); Group 2 = 33 (12.2*)
	SEXUAL RISK BEHAVIOUR (information in square brackets was not explicitly stated; assumed by review author ands):
	Mean (SD) % condom use in past 30 days: Group 1 = 79.23 (38); Group 2 = 77.47 (38)
	Mean (SD) % condom use in past 6 months: Group 1 = 72.44 (37); Group 2 = 70.38 (38)
	[Mean (SD) no. of] unprotected vaginal sex [acts] in past 30 days, n (%): Group 1 = 1. 12 (2.84); Group 2 = 0.84 (2.01)
	[Mean (SD) no. of] unprotected vaginal sex [acts] in past 6 months, n (%): Group 1 = 4.81 (16.01); Group 2 = 4.23 (10.25)
	Put condom on partner in past 6 months, 1 to 5 scale [mean (SD)]: Group 1 = 1.49 (1. 01); Group 2= 1.46 (0.98)
	Condom use skills (assessed by interviewer), scale scores [mean (SD)]: Group 1 = 2.91 (1.30): Group 2 = 3.03 (1.18)
	OTHER SEXUAL RISK OUTCOMES (*indicates an error in the % value reported in the primary publication; the correct value is given here):
	Consistent condom use in past 30 days: Group 1 = 60 (24.0*); Group 2 = 75 (27.7*)
	Consistent condom use in past 6 months, n (%): Group 1 = 101 (40.2*); Group 2=119 (43.9*)
	Condom use during last sex, n (%): Group 1 = 74 (29.5*); Group 2 = 79 (29.2*)
	Vaginal intercourse in the preceding 6 months was stated as a trial inclusion criterion
Interventions	GROUP 1: HIV prevention intervention (n = 251)
	YEAR STARTED: December 1996 to April 1999.
	PROVIDER(S): A trained female health educator and 2 female peer educators, all African American
	SETTING(S): Family medicine clinic.
	TYPE: Four group sessions each attended by 10 to 12 participants providing information/ education and practical skills development. The sessions covered ethnic gender and ethnic pride; HIV risk reduction strategies, sex refusal and safer sex negotiation and healthy relationships. The practical skills components involved practising safer sex negotiation, including sex refusal and developing condom skills as modelled by the peer educators
	DURATION: Four 4-hour sessions implemented weekly on consecutive Saturdays
	THEORETICAL BASIS: Social cognitive theory and the theory of gender and power
	STIs COVERED: HIV
	GROUP 2: General health promotion group (n = 271)
	YEAR STARTED: As Group 1.
	PROVIDER(S): Not reported; assumed as Group 1.
	SETTING(S): Not reported; assumed as Group 1.
	TYPE: Information/education. Four group sessions each attended by 10 to 12 participants; 2 of the sessions emphasised nutrition and 2 emphasised exercise
	DURATION: As Group 1.
	THEORETICAL BASIS: None reported.
	STIs COVERED: None.
Outcomes	PRIMARY:
	Self-reported consistent condom use (during every episode of vaginal intercourse), expressed as the total number of vaginal intercourse episodes divided by the total number of times a male condom was used, with a score of 1 representing consistent condom use
	SECONDARY:
	Condom use at last vaginal intercourse; percentage of condom-protected vaginal intercourse acts in the preceding 30 days and 6 months; number of unprotected vaginal intercourse acts in the preceding 30 days and 6 months; whether participants had a new vaginal sex partner in the preceding 30 days; and self-reported pregnancy
	Frequency with which participants applied condoms on their sex partners in the preceding 6 months, on a 5-point scale from ‘never’ to ‘every time’
	Frequency of vaginal sex acts in the previous 6 months.
	Incidence of chlamydia, trichomonas and gonorrhoea (HIV test not conducted due to expected low incidence)
	HIV knowledge; psychosocial mediators of condom behaviour (condom attitudes; condom barriers; condom self-efficacy; condom use skills; frequency of communication with partner about HIV preventive practices)
Notes	COST DATA: Reported only that participants were compensated $25 for travel and child care to attend intervention sessions and complete assessments
Risk of bias
Bias	Authors’ judgement	Support for judgement
Adequate sequence generation?	Low risk	Stated that prior to enrolment, an investigator used a random-numbers table to generate the allocation sequence
Allocation concealment?	Low risk	Stated that allocation concealment procedures were defined by protocol and compliant with published recommendations; as participants completed baseline assessments, sealed opaque envelopes were used to execute the assignments
Blinding? All outcomes	Low risk	Stated that face-to-face interviewers who assessed participants’ sexual behaviours were blind to group assignment. Not reported whether clinicians who diagnosed STIs based on participant-provided swabs were also blinded
Incomplete outcome data addressed? All outcomes	Low risk	Stated that no differences were observed in baseline variables for either group in participants retained in the trial compared with those unavailable for follow up. Although the GEE regression model used for analysing data over the 12 months post-baseline can account for missing data, the number ofvalues missing was not reported. For STI incidence, the authors stated that missing data for some covariates may affect the precision of effect estimates, but the co-variates in question were not stated However, attrition rates were balanced between study groups and reasons for attrition were given (which did not differ between groups)
Free of selective reporting?	Low risk	All outcomes presented in the methods section were also reported in the results section. Note that incidence of chlamydia, trichomonas and gonorrhoea was reported as an outcome although not explicitly stated as such in the methods section
Free of other bias?	High risk	Although adjusted for in the analysis, the trial groups were not equivalent at baseline on certain sexual behaviours