Age Distribution Modelling of HIV/AIDS Mortality in Kalyana Karnataka Region of Karnataka State: A Doubly Truncated Normal Approach

Abstract This study investigates the age-at-death distribution of HIV/AIDS mortality data in the Kalyana Karnataka region using a doubly truncated normal distribution. Age data were grouped into 15 intervals, and midpoint values were weighted by observed frequencies to reconstruct a full sample. Due to the natural bounds of human lifespan, a doubly truncated normal model—bounded between ages 0 and 89—was deemed appropriate. The maximum likelihood estimation (MLE) of distribution parameters (mean and standard deviation) was performed using numerical. The estimated parameters indicated a central tendency and dispersion in the observed mortality age distribution, with the fitted density aligning closely with the empirical histogram. This modelling approach effectively accounts for truncation in the data and offers improved interpretability for age-related mortality patterns. The results can assist in understanding HIV/AIDS mortality structure and support health policy planning.