Abstract:
ABSTRACT
Background: Renal failure is one among the slowly progressive diseases of kidney function
characterized generally by low glomerular filtration (GRF). The replacement therapy of renal
failure by hemodialysis involves the removal of excessive toxic fluids and toxic metabolic end
products from the body. One continuous and five categorical predictors were included in the
analysis. The mean baseline age of renal failure patients was 36.64 years. Out of 269 renal failure
patients 118(43.87%) were female and 150(55.76%) were hypertensive. Joint models typically
combine linear mixed effects models for repeated measurements and Cox models for censored
survival outcomes. Thus, the aim of this study was to present joint modelling on longitudinal
glomerular filtration rate measurement and time-to-death of renal failure patients treated under
hemodialysis.
Methods: Hospital based retrospective study was conducted among renal failure patients
attending hemodialysis between 2016 and 2018 at Saint Paulo’s Hospital Millennium Medical
College, Addis Ababa, Ethiopia. The longitudinal eGFR and the time to event (i.e. death) data with
the separate modeling approach and the joint modeling approach was fitted. A total of 269 renal
failure patients screened who were under hemodialysis follow-up at Saint Paulo’s Hospital
Millennium Medical College.
Results: The results for separate and joint models were quite similar to each other but not
identical. However, the estimates of the association parameters in the joint analysis were
significantly different from zero, providing evidence of association between the two sub-models.
The relationship between kidney function as measured by eGFR and the hazard for death was
negatively significant. Thus, death is less likely to occur in patients with higher eGFR.
Conclusions: When evaluating the overall performance of both the separate and joint models in
terms of model parsimony, goodness of fit, smaller total AIC, and the statistical significance of
both the association parameters, the joint model performs better. Thus, authors concluded that the
joint model was preferred for simultaneous analyses of repeated measurement and survival data.
Key words: Hemodialysis, Chronic Kidney Disease, Joint Model, Longitudinal Data, Survival
Data Cox PH model.