Comparison of Generalized Weibull and Weibull Parametric Models in Survival Analysis of Patients with Hypertension to Acute Renal Failure: Death due to Cardiovascular Disease as a Competing Risk

Hypertension is one of the most prevalent diseases affecting numerous people in different societies. One of the major complications of hypertension is the occurrence of acute renal failure. Therefore, it is important to evaluate the survival rate of patients with hypertension until the onset of acute renal failure and determine the factors affecting it.

This analytical study was conducted using modeling at the Kermanshah University of Medical Science within February 2016-July 2018. The current research examines the survival of patients with hypertension until acute renal failure using the Generalized Weibull Distribution model based on competing risks which included death due to cardiovascular disease. The required information was extracted from the Systolic Blood Pressure Intervention Trial (SPRINT) data file. 

Out of 842 patients, 85 died of cardiovascular diseases, 298 were diagnosed with acute renal failure, and 459 were censored. The mean survival time was 929.49 days and its median value was 1029 days. The Akaike value of the generalized Weibull model was less than the Weibull model. These results indicate that based on the generalized Weibull model, the variables of glomerular filtration rate, the number of antihypertensive drugs used on arrival, chronic kidney disease, albumin/creatinine ratio in urine, and gender were effective on the survival of patients.

As evidenced by the obtained results, the Akaike value of the generalized Weibull model is less than the generalized Weibull model. Therefore, the generalized Weibull model has a better fit, compared to the Weibull model.