MRC/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
Popul Health Metr. 2011 Aug 5;9:46. doi: 10.1186/1478-7954-9-46.
Verbal autopsy (VA) has often been used for point estimates of cause-specific mortality, but seldom to characterize long-term changes in epidemic patterns. Monitoring emerging causes of death involves practitioners' developing perceptions of diseases and demands consistent methods and practices. Here we retrospectively analyze HIV-related mortality in South Africa, using physician and modeled interpretation.
Between 1992 and 2005, 94% of 6,153 deaths which occurred in the Agincourt subdistrict had VAs completed, and coded by two physicians and the InterVA model. The physician causes of death were consolidated into a single consensus underlying cause per case, with an additional physician arbitrating where different diagnoses persisted. HIV-related mortality rates and proportions of deaths coded as HIV-related by individual physicians, physician consensus, and the InterVA model were compared over time.
Approximately 20% of deaths were HIV-related, ranging from early low levels to tenfold-higher later population rates (2.5 per 1,000 person-years). Rates were higher among children under 5 years and adults 20 to 64 years. Adult mortality shifted to older ages as the epidemic progressed, with a noticeable number of HIV-related deaths in the over-65 year age group latterly. Early InterVA results suggested slightly higher initial HIV-related mortality than physician consensus found. Overall, physician consensus and InterVA results characterized the epidemic very similarly. Individual physicians showed marked interobserver variation, with consensus findings generally reflecting slightly lower proportions of HIV-related deaths. Aggregated findings for first versus second physician did not differ appreciably.
VA effectively detected a very significant epidemic of HIV-related mortality. Using either physicians or InterVA gave closely comparable findings regarding the epidemic. The consistency between two physician coders per case (from a pool of 14) suggests that double coding may be unnecessary, although the consensus rate of HIV-related mortality was approximately 8% lower than by individual physicians. Consistency within and between individual physicians, individual perceptions of epidemic dynamics, and the inherent consistency of models are important considerations here. The ability of the InterVA model to track a more than tenfold increase in HIV-related mortality over time suggests that finely tuned "local" versions of models for VA interpretation are not necessary.
口头尸检（VA）常用于特定病因死亡率的点估计，但很少用于描述流行模式的长期变化。监测新出现的死因需要从业者对疾病形成认识，并要求采用一致的方法和实践。在此，我们使用医生的诊断和模型解读对南非与艾滋病相关的死亡率进行回顾性分析。
1992年至2005年间，阿金库尔分区发生的6153例死亡中有94%完成了口头尸检，并由两名医生和InterVA模型进行编码。医生判定的死因被汇总为每个病例单一的共识根本死因，对于存在不同诊断的情况，由另一名医生进行仲裁。比较了不同时间由个别医生、医生共识以及InterVA模型编码的与艾滋病相关的死亡率和死亡比例。
约20%的死亡与艾滋病相关，从早期的低水平到后期人群发生率高出十倍（每1000人年2.5例）。5岁以下儿童和20至64岁成年人中的发生率更高。随着疫情的发展，成人死亡率转向年龄更大的人群，65岁以上年龄组后期出现了显著数量的与艾滋病相关的死亡。早期InterVA结果显示，最初与艾滋病相关的死亡率略高于医生共识得出的结果。总体而言，医生共识和InterVA结果对疫情的描述非常相似。个别医生之间存在明显的观察者间差异，共识结果通常反映出与艾滋病相关的死亡比例略低。第一位医生与第二位医生的汇总结果没有明显差异。
口头尸检有效地检测到了与艾滋病相关的死亡率的非常显著的流行情况。使用医生诊断或InterVA在疫情方面得出了非常可比的结果。每个病例两名医生编码员（从14名中选取）之间的一致性表明，双重编码可能没有必要，尽管与艾滋病相关的死亡率的共识率比个别医生的结果约低8%。个别医生内部和之间的一致性、对疫情动态的个人认知以及模型的内在一致性在此都是重要的考虑因素。InterVA模型能够追踪与艾滋病相关的死亡率随时间增加超过十倍，这表明不需要针对口头尸检解读进行精细调整的“本地”版本模型。
