1. Effect of prepare Intervention on sexual initiation and condom use among adolescents in Dar es Salaam: Preliminary analysis

2. AIM Dar PREPARE Intervention aimed at examining the effect of the Intervention on; 1. Delaying sexual debut (Incidence of sexual debut/ action planning to delay sex) 2. Practice of safer sexual behavior (Use of condom during last sex/Action plan to use condom)

3. School selection and allocation 38 schools randomly selected t represent urban and semi-urban Dar es salaam Matched by size and location Allocated to the two arms (19 Intervention and 19 control schools )

4. Study Design Control Intervention F1 F2 InterventionBooster 6 months 12 months

5. Analysis Compare baseline socio-demographic and outcome scales by intervention status Examine and test best correlation structure for repeated measures ( use QIC) Examine change in mean scores overtime using extended generalized estimating equation modeling (xtgee)for repeated measures (Use QIC)

6. Use of GEE (xtgee) Repeated measures are positively correlated Correlation decrease by measurement occasion GEE- form of Generalized Linear Mixed Model Excellent for balanced design Change in link function accommodate Count (Poisson) or Binary (binomial) outcome Handle more then two measurement occasions Control for correlation

7. Schematic diagram of follow up rate Baseline 5091 Months 6 (F1) 4783 Months 12 (F2) 4370 Months 12 (F2) 4370 308 lost (6.0%) 413 lost (8.6%)

8. Baseline comparison A total 5091 participants in baseline Participants from control schools were significantly older than those from intervention school (12.39 versus 12.43; p=0.020) More from standard 6 (64.1% versus 61.8%; p=0.025) All other variables comparable (except HAVES, communication with friends and parents)

9. VariableInterventionControl Mean difference P-value Action plan condom use 2.5982.5780.01980.4743 Action plan delayed sex 2.8092.7930.15290.6163 Self-efficacy Communicate with peer 2.2662.2250.04070.0678 Peer communication 1.6461.6060.039440.0946 Communication with friends 1.3841.3380.04650.0007 Communication with parents 1.3381.3050.03350.0328 Self-efficacy to delay sex 2.5912.5960.00460.8614 Self-efficacy to use Condom 2.4392.4790.03960.0930 Social norms condom use 3.3523.4070.05490.0518 Social norm delay sex 3.5163.4870.02970.2780 Attitude delay sex (negative) 2.3212.2970.02390.3343 Attitude delay sex (positive) 3.433 0.00020.9936 Puberty knowledge 1.5041.5030.00050.9445 Myth about condom 2.2312.2440.01270.4939 Haves 3.7713.992-0.22080.0003 Baseline mean scale comparison between Intervention and control schools

10. Sexual activity and initiation Significantly large proportion of intervention group participants were sexually active (10.7% Intervention vs 8.9% control, p=0.026)

11. Incidence of sexual debut among female adolescent by intervention status Female Month 6 Month 12 Intervention N=1052 at risk Control N=1113 at risk 60 new initiation Incidence 11/100 PYAR 52 new initiation Incidence 9.0/100PYAR 75 new initiation Incidence 7/100PYAR 114 new initiation Incidence 9.7/100PYAR RR =1.6, p=0.024 *Assumption: Debut occurred mid follow time

12. Incidence of sexual debut among male adolescent by intervention status Male Month 6 Month 12 Intervention N=1158 at risk Control N=1213 at risk 65 new initiation Incidence 10.9/100 PYAR 78 new initiation Incidence 12.4/100PYAR 87 new initiation Incidence 7.2/100PYAR 126 new initiation Incidence 10.0/100PYAR RR =1.9, p<0.001 *Assumption: Debut occurred mid follow time

13. Change over time in mean scales for action plan to delay sex

14. Change over time in mean scales for action plan to use condom

15. Correlation and covariate structure pwcorr sex0 sex1 sex3 | sex0 sex1 sex3 sex0 | 1.0000 sex1 | 0.7000 1.0000 sex3 | 0.5791 0.8272 1.0000 corr sex0 sex1 sex3, cov | sex0 sex1 sex3 -------------+--------------------------- sex0 |.088426 sex1 |.080242.148585 sex3 |.074042.137103.184882

16. Intervention effect on the mean score : Female INTERVENTION CONTROL Variable OccasionCoefficientP-valueCoefficientP-value Action to delay sex baseline ref Month 6 0.04690.2560.05260.237 Month 12 0.10550.0330.06860.144 Group 0.13450.015 Action to use condom baseline ref Month 6 0.172<0.0010.1916<0.001 Month 12 0.1430.0010.1857<0.001 Group 0.01740.678 Sexual initiation baseline ref Month 6 0.0746<0.0010.0694 <0.001 Month 12 0.148<0.0010.1318 <0.001 Group 0.13610.009 Condom use baseline ref Month 6 0.1727<0.0010.2660<0.001 Month 12 0.2910<0.0010.30700.001 Group 0.01620.463

17. Intervention effect on the mean score : Male INTERVENTIONCONTROL Variable OccasionCoefficientP-valueCoefficientP-value Action to delay sex baseline ref Month 6 0.08390.0040.1049 <0.001 Month 12 0.1497<0.0010.1562 <0.001 Group 0.0030.633 Action to use condom baseline ref Month 6 0.07290.0480.05460.173 Month 12 0.18800.0190.09260.033 Group 0.07400.0876 Sexual initiation baseline ref Month 6 0.06560.0100.02720.530 Month 12 0.12490.0070.00920.843 Group 0.1126 0.043 Condom use baseline ref Month 6 0.3209<0.0010.14840.025 Month 12 0.3694<0.0010.2672<0.001 Group 0.2173 0.004

18. Conclusions The intervention was effective in; Promoting action plan to delay sex for both sex delaying sexual initiation for both male and female adolescents Condom use among male but not among women

19. Further analysis Examine intervention effectiveness in promoting other aspect of safer sex-multiple sexual partners Effective on communication, self efficacy etc Predictors of observed positive outcomes