BMC Public Health 2007, 7:349 http://www.biomedcentral.com/1471-2458/7/349 those given to women alone. INAs had more success invit- ing people they knew, compared with people they had just met. Invitations given by the INA accompanied by their spouse or another INA were not associated with a different response rate than those given by the INA alone (not shown). In both countries, invitations delivered after a public endorsement of CVCT were associated with a higher response rate. This association was not significant for Zambia, but remained of interest with an exploratory p-value < 0.10. Predictor variables with significant univariate effects (p < .05 in either country) were examined in the context of multi-predictor HLM analysis. Because years cohabiting, number of children, age of the man, and age of the woman were all highly correlated with each other (all r's ≥ 60), only the age of the man was included in order to minimize potential multicollinearity. None of the INA- level predictors achieved statistical significance in the uni- variate analysis, so these variables were excluded from the multi-predictor models. Table 4 presents the results of the multi-predictor analysis and confirms that invitations given in the INA home, workplace, and (in Zambia only) the couples' home remained independent predictors of CVCT. Similarly, invitations to couples and public endorsement remained predictive in the multivariate model. Invitations to family and to friends and social or professional contacts were independently predictive of success in Zambia but did not remain significant in Rwanda when controlled for the other variables measured. Discussion Strategies that attempt to modify behaviour remain the cornerstone of HIV prevention efforts [29]. Couples' VCT can provide life-saving benefits, reduce HIV transmission, sexually transmitted infections, and unintended pregnan- cies among couples [7,9,30-40]. There is now a growing consensus that CVCT should be widely disseminated, but many cultural and logistical obstacles remain [6]. This study confirms that influential members of the commu- nity are willing and able to promote CVCT in Africa. Although there were differences in the impact of CVCT promotion between Kigali, Rwanda and Lusaka, Zambia, the predictors of success were similar. We recruited and trained a broad range of Influence Net- work Agents to promote CVCT through one-on-one con- tacts and written invitations. Our previous work successfully used paid Community Workers (CWs) as full- time promoters of CVCT. When CW outreach was discon- tinued due to achievement of research enrollment targets, attendance at CVCT sites declined [4,5]. The INA model was implemented in order to increase community aware- ness of CVCT and ensure sustainability. INAs self-identified with one of four main categories in this study, but many INAs wore more than one 'hat' and used a variety of networks, including friends, family, pro- fessional contacts, and social settings to promote CVCT. Table 4: Summary of effects from multi-predictor HLM analyses for predicting CVCT response rates- Rwanda and Zambia Couple/Invitation Level Predictors Age of man Location of invitation* Couple Home vs. Community INA Home vs. Community Workplace vs. Community Person(s) invited Couple vs. Woman Man vs. Woman Relationship to INA Family member vs. Just met Social acquaint. vs. Just met Public endorsement *Workplace = Clinic and Workplace Community = Church, Market, Social Gathering, and Other OR 1.013 1.262 3.398 1.788 1.638 1.213 1.760 1.070 1.756 Rwanda 95% CI 1.006 – 1.024 0.902 – 1.764 2.150 – 5.368 1.209 – 2.644 1.253 – 2.142 0.940 – 1.566 0.844 – 3.672 0.842 – 1.358 1.140 – 2.708 p 0.015 0.200 < .001 0.004 0.001 0.137 0.131 0.581 0.011 OR 1.017 1.596 3.267 1.671 1.733 1.059 1.698 1.810 1.705 Zambia 95% CI 1.007 – 1.025 1.135 – 2.243 2.174 – 4.909 1.143 – 2.443 1.363 – 2.202 0.841 – 1.334 1.110 – 2.599 1.395 – 2.347 1.075 – 2.704 p < .001 0.008 < .001 0.008 < .001 0.623 0.015 < .001 0.023 Page 7 of 10 (page number not for citation purposes)