Survival Analysis of Glaucoma Patients Until Blindness: The Case of University of Gondar Comprehensive Specialized Hospital, Gondar, Ethiopia

Abstract

The objective of the study was to identify the best-fitted survival regression model and to find factors that accelerate the time of blindness of glaucoma patients in University of Gondar Comprehensive Specialized Hospital. Material and Methods: Secondary data was taken from the patient’s card, collected from January 2014-April 2018 in the hospital. In this study 401 glacoma patients’ record was considered. Kaplan-Meier survival analysis, Semiparametric and Parametric AFT model were applied to identify factors that lead blindness of glaucoma patients. Results: From the total 401 glaucoma patients 23.69% was blind. From the total sample 38.41% and 61.59% were female and male glaucoma patients, respectively. The median time of blindness for the two eyes or one eye was 16 months after confirmation of glaucoma disease. In the multivariable Weibull accelerated failure-time model it has found that age group (18-43) (TR =1.29233, CI: 1.039576 to 1.606536), advanced stage of glaucoma (TR =1.281674, CI: 1.096103 to 1.498662), duration of diagnosis 1-5 years (TR = 1.944649, CI: 1.332738 to 2.83751) and duration of diagnosis >= 6 years (TR = 2.683586, CI: 1.367533 to 5.26615) were significantly associated with the time to blindness. Conclusion: The multivariable Weibull model revealed that age, duration of diagnosis and stage of glaucoma were major factors that affect the survival probability of glaucoma patients. Finally, based on the results of the study we can conclude that the Weibull regression model was the best fitted parametric accelerated failure-time model for identifying the major factors related to glaucoma patients.