Longitudinal study of change in CD4+ cell counts on HIV-Positive patients at Dalhatu Araf Specialist Hospital, Lafia

Abstract

The aim of this study was the Longitudinal Study of Change in CD4+ Cell Counts on HIV-Positive Patients at Dalhatu Araf Specialist Hospital, Lafia. The study deployed linear mixed effects models to check if the mean response CD4+ cell count varies with time. The study also attempted to test if the mean response varies in the two groups. An attempt to estimate the relationship between the response and observations according to gender. The study revealed that the trajectory of the mean response over time has a very high variability where we see that there is a general rise in the CD4+ cell counts at the initiation of ART. It was further seen that the CD4+ cell counts in male patients is observed to be higher with higher median value after the sixth observation. A linear mixed effect model was used and tested where it was noted that there is evidence of between-individual heterogeneity which further shows that the decision to choose a mixed effects model instead of an only fixed effects model was in order. The model summary showed that the mean CD4+ cell counts at the baseline (OBS1) was averagely good, but at the initiation of ART, there was a significant increase in the mean response where it was further revealed that the pattern of the mean response over time is not flat. In modelling the group effects, we see the difference between the mean CD4 cell count of male versus female is -113.62 CD4 cell count (i. e. 95% CI= -290.64 to 63.39) lower than female, adjusting with time. Finally, the Wald test does not show any significant evidence of interaction between the observations and gender (p=0.2925) which suggests that the mean response based on gender may be parallel.