Tiruneh Firew, Chewaka Lalisa, Abdissa Dinaol
Department of Midwifery, College of Health Science, Mizan Tepi University, Mizan Teferi, SNNPR, Ethiopia.
Department of Nursing, College of Health Science, Mizan Tepi University, Mizan Teferi, SNNPR, Ethiopia.
HIV AIDS (Auckl). 2021 Jan 22;13:73-79. doi: 10.2147/HIV.S283059. eCollection 2021.
In much epidemiological HIV research, patients are often followed over a period of time to predict their survival on the basis of repeatedly measured CD4 status. To predict survival, statistical models of the association between mortality and longitudinal CD4 measurement have been conducted widely using time-varying Cox models. However, in the presence of repeated measure, this approach leads to biased estimates. In view of the limitation of time-varying Cox models, in the present study, we considered joint modeling to predict the association of longitudinal CD4 measurement and time to death among patients initiated on ART.
A retrospective cohort study was employed for five years from 2009 to 2014 on a randomly selected 358 samples. Data were collected from patients' ART and pre-ART follow-up registration book, database and other clinical records. Data were analyzed using joint latent class modeling of repeated CD4 measurement and time-to-event (HIV death).
We have studied a total of 358 HIV-positive patients. The median and interquartile ranges of the age of patients were 30.31 years and 13.82, respectively. Males constitute the larger proportion, 51.68%. The square root of CD4 count has declined on average over time. This has been indicated with the negative sign of the coefficient for the time effect. The deterioration of health of individuals is severe in class 1, it has been observed with a worse decline in CD4 cell counts over time in this class than other classes (= -0.488). Women had a larger risk rate than men (=-2.475, -value=0.013). Besides, the CD4 counts measurement of patients has been revealed to decrease as age increases (= -0.016, =0.008).
The finding indicated that the square root CD4 cell measurement dropped over time in the three classes. This clearly suggested deterioration in the health of individuals. Women were found to have a higher hazard rate than men.
在许多艾滋病病毒流行病学研究中，通常会对患者进行一段时间的随访，以便根据反复测量的CD4状态预测其生存情况。为了预测生存情况，使用时变Cox模型广泛开展了死亡率与纵向CD4测量之间关联的统计模型研究。然而，在存在重复测量的情况下，这种方法会导致估计有偏差。鉴于时变Cox模型的局限性，在本研究中，我们考虑采用联合建模来预测接受抗逆转录病毒治疗（ART）患者的纵向CD4测量与死亡时间之间的关联。
采用回顾性队列研究，对2009年至2014年随机选取的358个样本进行了为期五年的研究。数据收集自患者的抗逆转录病毒治疗及治疗前随访登记册、数据库和其他临床记录。使用重复CD4测量和事件发生时间（艾滋病病毒死亡）的联合潜在类别模型对数据进行分析。
我们共研究了358名艾滋病病毒阳性患者。患者年龄的中位数和四分位间距分别为30.31岁和13.82岁。男性占比更大，为51.68%。CD4细胞计数的平方根随时间平均下降。这已通过时间效应系数的负号得到体现。在第1类中个体健康状况恶化严重，观察发现该类中CD4细胞计数随时间的下降比其他类别更严重（=-0.488）。女性的风险率高于男性（=-2.475，P值=0.013）。此外，已发现患者的CD4细胞计数测量值随年龄增加而降低（=-0.016，=0.008）。
研究结果表明，在这三类中CD4细胞测量值随时间下降。这清楚地表明个体健康状况恶化。发现女性的危险率高于男性。
