Table 4.

Generalized Estimating Equations Model-based Significance Tests and Effect Size Estimates for the Intervention Effect on Self-Reported Sexual Behavior and psychological variables over the 12-Month Follow-up Period; University students in Eastern Cape Province, South Africa

Outcome	N	Estimatea (95% CI)	Z	P valueb	Cohen’s d c
Frequency of unprotected vaginal intercourse in the past 3 months	172	0.28 (0.08, 0.97)	−2.01	.045	0.31
Frequency of condom use in the past 3 monthsd	95	2.82 (1.18, 6.74)	2.34	.020	0.49
Frequency of vaginal intercourse in the past 3 months	171	1.22 (0.77, 1.95)	0.84	.400	−0.13
Percentage report multiple sexual partners	171	1.04 (0.96, 1.13)	0.97	.334	−0.15
Condom-use outcome expectancies	173	0.15 (0.04, 0.26)	2.57	.010	0.40
Self-efficacy to use condoms	173	0.12 (0.01, 0.24)	2.05	.040	0.32
HIV risk-reduction knowledge	173	1.08 (0.64, 1.51)	4.85	<.0001	0.79
Condom-use knowledge	173	0.14 (0.01, 0.27)	2.04	.041	0.31

^aEstimate is the event rate ratio (intervention or health control) for frequency of unprotected vaginal intercourse, the odds ratio for multinomial outcome frequency of condom use, the rate ratio for multiple partners incidence, and the mean difference for psychological variables.

^bP value is the two-tailed significance probability.

^cCohen’s d is a measure of effect size in standard deviation units.

^dFrequency of condom use was rated on a scale from “1” (never) to “5” (always).