P1-S6.46 The long-term impact of the MEMA kwa Vijana adolescent sexual and reproductive health intervention: effects of dose and time since exposure to intervention
Authors: Doyle A M , Weiss H A , Maganja K , McCormack S , Watson-Jones D , Changalucha J , Hayes R J , Ross D A 
Published: July 2011

Background

Despite recent decreases in HIV incidence in many countries in sub-Saharan Africa, there is little evidence that specific behavioural interventions have led to a reduction in HIV among young people. Further and wider-scale decreases in HIV will require better understanding of when behaviour change occurs and why. The MEMA kwa Vijana adolescent sexual and reproductive health intervention has been implemented in rural Mwanza, Tanzania since 1999. A long-term (9 yr) evaluation found that the intervention had improved knowledge, reported attitudes to sex and some sexual risk behaviours but not HIV or HSV2 prevalence. An evaluation of impact in 2001 found strong evidence that receiving more years of the intervention (dose) was associated with a larger impact on some outcomes. We explored whether there was long-term differential intervention impact according to age, marital status, dose of intervention, or time since last exposure to the in-school component of the intervention.

Methods

In 2007, a cross-sectional survey was conducted in the 20 MEMA kwa Vijana trial communities among 13814 young people (15–30 yrs) who had attended years 5–7 at intervention or comparison schools between 1999 and 2002. Only outcomes for which the intervention was shown to have an impact in 2001 or 2007 were included in this subgroup analysis that is, knowledge, reported attitudes, selected reported behaviours (age at first sex; number of partners; condom use). Data were analysed using cluster-level methods for stratified cluster-randomised trials with interaction tests to determine if intervention impact differed according to subgroup.

Results

Taking into account multiplicity of testing, concurrence with a priori hypotheses and consistency within the results no strong effect modifiers emerged. There was some evidence of a dose-response effect. Specifically, impact on pregnancy knowledge increased with increasing high-quality dose of the intervention in both sexes, especially among males (Abstract P1-S6.46 table 1). There was some evidence of an impact of the high-quality dose of intervention on overall sexual attitudes among females. The consistency of these findings suggests that they are highly plausible.

Abstract P1-S6.46 Table 1

Impact of intervention in 2007/8 according to number of years of exposure to in-school intervention (1999–2002)*

OutcomeOverallYears of in-school intervention (‘99-‘02)Test for trend (p value)1 yr2 yrs3+ yrsHIV acquisition knowledge (% with all 3 responses “correct”) Male1.11 (0.99, 1.23)*1.091.121.120.56 Female1.11 (1.00, 1.24)*1.121.111.120.85STD acquisition knowledge (% with all 3 responses “correct”) Male1.18 (1.04, 1.34)**1.191.201.160.70 Female1.24 (0.97, 1.58)*1.221.211.320.32Pregnancy prevention knowledge (% with all 3 responses “correct”) Male1.19 (1.12, 1.26)**1.131.191.250.0001** Female1.17 (1.06, 1.30)**1.121.201.190.03**Attitudes to sex (% with all 3 responses “correct”) Male1.31 (0.97, 1.77)*1.261.331.380.15 Female1.09 (0.67, 1.77)0.781.231.250.008**

Conclusions

The desirable long-term impact of the MEMA kwa Vijana intervention did not vary greatly according to the subgroups examined. From a programme implementation point of view this suggests that the intervention can have an impact on a broad cross-section of young people in rural Mwanza.