Estimation of life expectancy, loss-of-life expectancy, and lifetime healthcare expenditures for schizophrenia in Taiwan

By employing a novel semi-parametric extrapolation method, the life expectancies after the first hospitalization for schizophrenia and the associated lifetime healthcare expenditures were both estimated. Based on the linkage between the National Health Insurance Research Database and the National Mortality Registry of Taiwan, we have established a schizophrenic cohort for 2000-2010 and followed up to 2011. Survival function was estimated through Kaplan-Meier's method and extrapolated throughout life. We applied a simple linear regression to the logit-transformed survival ratio between the schizophrenic cohort and the sex-, age-matched referents via Monte Carlo simulation from the national life table. The monthly survival probability was multiplied by the average healthcare expenditures and summed throughout life to estimate the lifelong cost reimbursed by the National Health Insurance. The results showed that patients diagnosed at age 20-29 had the highest expected years of life lost (EYLL), 15 and 9years, in men and women, respectively, with corresponding lifetime healthcare expenditures of USD 48,000 and 53,000. Males generally had higher health cost per life-year than their female counterparts across their lifespan. We applied the same method to the first 6years of the cohort and extrapolated to 12years, which showed that the relative biases for different age strata were less than 5%. We thus concluded that the semi-parametric extrapolation method might provide a timely estimation of lifetime outcomes for health care planning of schizophrenia.