Imputation Methods for a Bathtub Hazard Model with Right-Censored and Interval-Censored Data
In this study, we extended a two-parameter bathtub hazard model that exhibits either an increasing or a bathtub-shaped failure rate depending on its shape parameter. The model was expanded to include covariates in the presence of right- and interval-censored data. To handle interval-censored data, we employed two imputation techniques: midpoint and random imputation. A simulation study was conducted to evaluate and compare the performance of these imputation methods using standard error (SE) and root mean square error (RMSE) values. The findings indicated that rando