BMC Public Health 2007, 7:349 http://www.biomedcentral.com/1471-2458/7/349 than Rwandan INAs (mean 96, S.D. 99), with greater var- iation among Rwandan INAs. Multiple regression analy- ses within each country separately revealed that the number of invitations distributed did not vary signifi- cantly by INA category, gender, age, marital status, or whether the INA had received HIV testing. Although Rwandan INAs distributed fewer invitations, they had a higher response rate. As a result, the average number of couples tested per INA was not significantly different in the two countries (26 in Rwanda, 21 in Zam- bia). The main determinant of INA performance in Rwanda was the number of invitations distributed, as response rates were > = 20% for 22/28 INAs. In Zambia, only 2/33 INAs had response rates > = 20% and only 12/ 33 exceeded response rates of 10%. In Zambia, all INAs distributed a large number of invitations but had fewer invitees present for CVCT services. In both countries, there were a few 'high performing' individuals, who had both high numbers of invitations and a high response rate. Predictors of successful invitations Table 3 summarizes the effects of univariate HLM analyses predicting response rates in each country separately. For categorical variables (e.g., location of invitation, INA cat- egory), dummy-coded vectors were entered as a set with the last category serving as a reference for the other catego- ries. None of the INA-level measures were predictive of successful invitations in either country. Among invited couples, older age in men was marginally predictive of seeking testing in Rwanda, while older age in men and women and longer cohabitation were significant predictors in Zambia. In both countries, invitations deliv- ered in the INA home were strongly predictive of a suc- cessful outcome, and workplace invitations also had a comparatively good yield. In Zambia, invitations deliv- ered at the couples' home were also more likely to result in couples seeking testing compared to the "community" reference group. Invitations delivered to couples were associated with the greatest likelihood of CVCT, and those given to men were more likely to result in testing than Table 3: Summary of univariate effects from HLM analyses for predicting CVCT response rates in Rwanda and Zambia Couple/Invitation Level Predictors Years cohabiting Number of children Age of man Age of woman Place 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 Friend/Social/Professional vs. Just met Public endorsement INA level Predictors Religious vs . Private NGO/CBO vs . Private Health vs. Private Gender (M = 1, F = 0) Age of INA Married (Y = 1, N = 0) INA HIV tested (Y = 1, N = 0) *Workplace = Clinic and Workplace Community = Church, Market, Social Gathering, and Other OR 1.011 0.991 1.01 1.008 1.318 3.546 1.792 1.559 1.324 1.503 1.263 1.535 1.536 0.966 0.867 2.48 1.014 1.135 0.923 Rwanda 95% CI 0.996 – 1.026 0.941 – 1.043 1.009 – 1.011 0.996 – 1.021 0.944 – 1.839 2.281 – 5.524 1.225 – 2.621 1.215 – 1.999 1.053 – 1.665 0.738 – 3.060 1.015 – 1.573 1.067 – 2.207 0.355 – 6.659 0.237 – 4.070 0.247 – 3.048 0.912 – 6.742 0.966 – 1.050 0.403 – 3.198 0.331 – 2.575 p 0.141 0.725 0.057 0.183 0.104 < .001 0.003 0.001 0.017 0.262 0.036 0.021 0.551 0.961 0.817 0.07 0.572 0.803 0.874 OR 1.03 1.005 1.017 1.017 1.432 3.248 1.583 1.918 1.218 1.984 1.917 1.435 1.278 2.09 1.052 0.976 0.996 1.211 0.633 Zambia 95% CI 1.017 – 1.043 0.958 – 1.055 1.008 – 1.026 1.007 – 1.027 1.047 – 1.958 2.212 – 4.769 1.104 – 2.269 1.531 – 2.402 0.983 – 1.510 1.320 – 2.982 1.495 – 2.458 0.942 – 2.185 0.559 – 2.922 0.821 – 5.319 0.438 – 2.520 0.512 – 1.861 0.967 – 1.027 0.535 – 2.742 0.333 – 1.205 p < .001 0.83 < .001 0.002 0.025 < .001 0.013 < .001 0.071 0.001 < .001 0.092 0.549 0.117 0.907 0.94 0.806 0.635 0.157 Page 6 of 10 (page number not for citation purposes)