Firew Tiruneh1, Lalisa Chewaka2, Dinaol Abdissa1,3. 1. Department of Midwifery, College of Health Science, Mizan Tepi University, Mizan Teferi, SNNPR, Ethiopia. 2. Department of Nursing, College of Health Science, Mizan Tepi University, Mizan Teferi, SNNPR, Ethiopia. 3. Department of Nutrition and Reproductive Health, School of Public Health, College of Health Science, Mizan Tepi University, Mizan Teferi, SNNPR, Ethiopia.
Abstract
BACKGROUND: 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. METHODS: 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). RESULTS: 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 (β= -0.488). Women had a larger risk rate than men (β=-2.475, p-value=0.013). Besides, the CD4 counts measurement of patients has been revealed to decrease as age increases (β= -0.016, p=0.008). CONCLUSION: 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.
BACKGROUND: 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. METHODS: 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). RESULTS: 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 (β= -0.488). Women had a larger risk rate than men (β=-2.475, p-value=0.013). Besides, the CD4 counts measurement of patients has been revealed to decrease as age increases (β= -0.016, p=0.008). CONCLUSION: 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.
Authors: Margaret T May; Jorg-Janne Vehreschild; Adam Trickey; Niels Obel; Peter Reiss; Fabrice Bonnet; Murielle Mary-Krause; Hasina Samji; Matthias Cavassini; Michael John Gill; Leah C Shepherd; Heidi M Crane; Antonella d'Arminio Monforte; Greer A Burkholder; Margaret M Johnson; Paz Sobrino-Vegas; Pere Domingo; Robert Zangerle; Amy C Justice; Timothy R Sterling; José M Miró; Jonathan A C Sterne; Andrew Boulle; Christoph Stephan; Jose M Miro; Matthias Cavassini; Geneviève Chêne; Dominique Costagliola; François Dabis; Antonella D'Arminio Monforte; Julia Del Amo; Ard Van Sighem; Gerd Fätkenheuer; John Gill; Jodie Guest; David Hans-Ulrich Haerry; Robert Hogg; Amy Justice; Leah Shepherd; Neils Obel; Heidi Crane; Colette Smith; Peter Reiss; Michael Saag; Tim Sterling; Ramon Teira; Matthew Williams; Robert Zangerle; Jonathan Sterne; Margaret May; Suzanne Ingle; Adam Trickey Journal: Clin Infect Dis Date: 2016-03-29 Impact factor: 9.079