Crosby Richard, Bounse Sarah
College of Public Health, University of Kentucky, 121 Washington Avenue, Lexington, KY 40506-0003, USA.
Sex Health. 2012 Mar;9(1):10-7. doi: 10.1071/SH11036.
After performing a review of prospective cohort evaluations, a focussed assessment of the current knowledge base and methodology pertaining to condom effectiveness against sexually transmissible infections, including HIV, was also conducted. Key observations included the point that studies of condom effectiveness are inherently complex and the potential forms of study bias all generally favour the null hypothesis. Perhaps the most challenging obstacle to rigor in these studies lies in determining which events of condom-protected sex occurred before infection as opposed to after infection when, in fact, infection occurs. This problem leads to misclassification bias; however, other sources of misclassification bias are common. Greater attention to the selection of a recall period, improved precision of self-reported measures, and accounting for condom use errors and problems are critical steps that must occur to promote rigor in these studies. Despite multiple shortcomings, prospective studies of condom effectiveness provide a reasonably favourable evaluation. Subsequent studies, however, should be designed to greatly reduce the error variance that predisposes condom effectiveness studies to type 2 errors that mask the potential value of condoms.
在对前瞻性队列评估进行审查之后，还对当前有关避孕套预防包括艾滋病毒在内的性传播感染有效性的知识库和方法进行了重点评估。主要观察结果包括，避孕套有效性研究本质上很复杂，而且研究偏差的潜在形式通常都有利于零假设。这些研究中严谨性面临的最具挑战性的障碍可能在于，确定哪些有避孕套保护的性行为发生在感染之前，而不是在实际发生感染之后。这个问题会导致错误分类偏差；然而，其他错误分类偏差来源也很常见。更加关注回忆期的选择、提高自我报告措施的精确度以及考虑避孕套使用错误和问题，是提高这些研究严谨性必须采取的关键步骤。尽管存在多种缺陷，但避孕套有效性的前瞻性研究提供了较为有利的评估。然而，后续研究应设计得能大幅减少误差方差，这种误差方差使避孕套有效性研究容易出现II类错误，从而掩盖了避孕套的潜在价值。
