Kincaid D Lawrence, Babalola Stella, Figueroa Maria Elena
Center for Communication Programs, Department of Health, Behavior and Society, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD.
J Acquir Immune Defic Syndr. 2014 Aug 15;66 Suppl 3:S278-84. doi: 10.1097/QAI.0000000000000242.
Since the 1990s, communication programs in South Africa have promoted HIV prevention, especially condom use. Although HIV prevalence stabilized after 2000, surveys have not clarified how prevention behavior contributed to that change. We present a secondary statistical analysis of the 2005 national South African Human Sciences Research Council survey that reveals how condom use at sexual debut-which normally occurs before infection from unprotected sex-may have contributed to the reduction in HIV infection.
Threats from measured and unobserved confounding variables are addressed through the use of several complementary statistical methods including structural equation modeling with multivariate probit regression and propensity score matching. The latter is used to create statistically comparable groups of those who used and did not use condoms at sexual debut to estimate the number of HIV infections averted attributed to this behavior.
After controlling for 17 socioeconomic variables, awareness of HIV communication programs had a positive, dose-response relationship with self-reported condom use at sexual debut. Those who used condoms at sexual debut were 1.38 times more likely to have remained uninfected. HIV-negative status was 3.6 percentage points higher among those who used condoms at sexual debut, corresponding to an estimated 139,835 infections averted among sexually active adults by 2005. Never using injectable drugs and having 1 trusted partner also predicted HIV-negative status.
We found a relationship between HIV communication awareness and condom use at sexual debut. Condom use at sexual debut, in turn, was associated with lower subsequent HIV risk.
自20世纪90年代以来，南非的宣传项目一直在推动艾滋病病毒预防工作，尤其是避孕套的使用。尽管2000年后艾滋病病毒感染率趋于稳定，但调查尚未明确预防行为是如何促成这一变化的。我们对2005年南非人类科学研究委员会的全国性调查进行了二次统计分析，该分析揭示了首次性行为时使用避孕套（通常发生在因无保护性行为感染之前）可能是如何促使艾滋病病毒感染率下降的。
通过使用几种互补的统计方法来解决测量到的和未观察到的混杂变量的威胁，这些方法包括带有多变量概率回归的结构方程模型和倾向得分匹配。后者用于创建在首次性行为时使用和未使用避孕套的具有统计学可比性的群体，以估计归因于这种行为而避免的艾滋病病毒感染数量。
在控制了17个社会经济变量后，对艾滋病病毒宣传项目的认知与首次性行为时自我报告的避孕套使用呈正的剂量反应关系。在首次性行为时使用避孕套的人未感染的可能性高1.38倍。在首次性行为时使用避孕套的人中，艾滋病病毒阴性状态高出3.6个百分点，这相当于到2005年估计有139,835名性活跃成年人避免了感染。从未使用注射毒品以及有1个可信赖的伴侣也预示着艾滋病病毒阴性状态。
我们发现了艾滋病病毒宣传认知与首次性行为时避孕套使用之间的关系。反过来，首次性行为时使用避孕套与随后较低的艾滋病病毒感染风险相关。
