Modeling Viral Load Using Mixed Effects Regression Models and Generalized Estimating Equations
Abstract
Properly implemented antiretroviral therapy (ART) program has significant impact on the lives of people living with HIV. This program is affected by various socioeconomic factors in Namibia that derails its effectiveness. This study applies linear mixed effects and generalized estimating equation (GEE) models to analyze factors that affect viral load in a cohort of 154 people living with HIV on ART in Karas Region, Namibia. The patients were followed up at the Luderitz Hospital from January 2015 to December 2017. The data were analyzed using R software version 4.4.1. The results from both models showed that male patients were associated with increased log viral load compared to females, while patient’s baseline weight was inversely related with log viral load. Overall, the directions of estimates were similar between the two models. But the linear mixed effects model produced estimates with smaller standard errors compared to the GEE model. In addition, based on the linear mixed effects model, it was shown that there was high variation of log viral load between patients as time passed. We recommend applying the linear mixed effects model when analyzing ART panel data.
| Original language | en |
| Pages (from-to) | 177-192 |
| Publication status | Published - 2025 |