Raab G M, Fielding K L, Allardice G
MRC Biostatistics Initiative for HIV and AIDS in Scotland, Edinburgh, U.K.
Stat Med. 1994;13(19-20):2009-20. doi: 10.1002/sim.4780131911.
For AIDS cases in Scotland the date of HIV antibody positive diagnosis (HIV test date) is recorded on the AIDS case reports. Data are also available on the total numbers of individuals with HIV positive test reports in Scottish laboratories in each year since testing became available. These data are incorporated into a model of the HIV epidemic described in terms of testing rates by calendar year. The HIV infection curve is modelled as a step function, and the testing rates are allowed to differ between steps. Results are presented for intravenous drug users (IDUs) and for homosexual/bisexual men. The estimated rates of testing for the IDUs (estimates from 19 per cent to 44 per cent per year) are considerably higher than those for homosexual/bisexual men (estimates of 10 per cent to 17 per cent per year). Data on the year of testing for AIDS diagnoses gave relatively little improvement in estimates of the HIV infection curve. However, when this information is combined with data on the total number of HIV positive diagnoses per year, there is a dramatic improvement in the estimate of the HIV infection curve. This is particularly marked for infections in the most recent period and for the estimates of cumulative infections up to the present. However, these improvements are gained at the cost of assumptions of similar testing rates applying to all sections of the HIV infected populations, which will be difficult to check in practice. This suggests that these methods should not be used in isolation but in combination with other evidence about the spread of HIV infection in a population.
对于苏格兰的艾滋病病例，艾滋病病例报告中记录了艾滋病毒抗体阳性诊断日期（艾滋病毒检测日期）。自检测开展以来，每年苏格兰各实验室艾滋病毒检测呈阳性报告的个体总数数据也可获取。这些数据被纳入到一个按日历年检测率描述的艾滋病毒流行模型中。艾滋病毒感染曲线被建模为一个阶梯函数，且不同阶梯的检测率允许有所不同。给出了静脉注射吸毒者（IDU）以及男同性恋者/双性恋男性的结果。IDU的估计检测率（每年估计为19%至44%）显著高于男同性恋者/双性恋男性（每年估计为10%至17%）。艾滋病诊断检测年份的数据在艾滋病毒感染曲线估计方面改善相对较小。然而，当该信息与每年艾滋病毒阳性诊断总数数据相结合时，艾滋病毒感染曲线的估计有显著改善。这在最近时期的感染情况以及截至目前的累积感染估计方面尤为明显。然而，这些改善是以假设适用于所有艾滋病毒感染人群各部分的检测率相似为代价的，而这在实际中很难核实。这表明这些方法不应单独使用，而应与关于人群中艾滋病毒感染传播的其他证据结合使用。
