aDivision of Infectious Diseases, Department of Medicine bDepartment of Epidemiology, Gillings School of Global Public Health cDivision of Women's Primary Healthcare, Department of Obstetrics and Gynecology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
AIDS. 2013 Oct;27 Suppl 1:S45-53. doi: 10.1097/QAD.0000000000000037.
To examine different scenarios through which confounding by condom use may lead to inaccurate conclusions about the effect of hormonal contraception on HIV acquisition in women.
Scenario analyses were conducted to evaluate the impact of coarse adjustment for condom use and condom misreporting on adjusted relative risk estimates for HIV acquisition in injectable hormonal contraception (IHC) users vs. nonusers.
Analyses crudely accounting for condom use through a binary variable result in biased hormonal contraception-related risk estimates if condoms are used during follow-up periods in which any unprotected sex is reported and condom use differs by hormonal contraception use. We found that over-reporting of condom use is plausible in at least one recent study, as demonstrated by high pregnancy rates given, reported IHC and condom use. Over-reporting of condom use also biases estimates, typically leading to underestimation of IHC-related risk if over-reporting is the same among IHC and non-hormonal contraception users, and overestimation of IHC-related risk if condom misreporting is differential by IHC use. The impact of misreported condom use is most pronounced in study populations with high condom uptake.
Discrepant findings in hormonal contraception-HIV-related research may result from inadequate measurement or adjustment for confounding by condom use. Future studies should precisely account for condom use in statistical analyses. Studies should aim to quantify the degree of condom use misreporting, by comparing reported condom use to pregnancy, HIV or other sexually transmitted infection rates, and if possible, testing stored genital swabs for prostate-specific antigen or Y chromosome.
通过分析不同的情况，探讨 condom use（避孕套使用）混杂可能导致关于激素避孕对女性 HIV 感染影响的不准确结论。
进行情景分析，以评估对 condom use（避孕套使用）进行粗略调整和 condom misreporting（避孕套报告错误）对接受注射型激素避孕（IHC）和不接受 IHC 的女性 HIV 感染调整后相对风险估计的影响。
如果在报告任何无保护性行为且 condom use（避孕套使用）因激素避孕使用而异的随访期间使用 condom（避孕套），通过二元变量粗略考虑 condom use（避孕套使用）会导致与激素避孕相关的风险估计偏倚。我们发现，至少在一项最近的研究中， condom use（避孕套使用）的高报告率是合理的，因为考虑到报告的 IHC 和 condom use（避孕套使用），怀孕率很高。 condom use（避孕套使用）的高报告率也会导致估计值偏倚，如果 IHC 和非激素避孕使用者的 condom use（避孕套使用）报告错误相同，则会低估 IHC 相关风险，如果 condom misreporting（避孕套报告错误）因 IHC 使用而异，则会高估 IHC 相关风险。 condom use（避孕套使用）报告错误的影响在 condom 使用率高的研究人群中最为明显。
激素避孕与 HIV 相关研究中的不一致发现可能是由于 condom use（避孕套使用）混杂的测量或调整不足所致。未来的研究应在统计分析中准确考虑 condom use（避孕套使用）。研究应旨在通过将报告的 condom use（避孕套使用）与怀孕、HIV 或其他性传播感染率进行比较，尽可能对储存的生殖器拭子进行前列腺特异性抗原或 Y 染色体检测，来量化 condom use misreporting（避孕套报告错误）的程度。
