A Microsimulation Model to Estimate Errors in Cross Sectional Estimates of Disability-Adjusted Life Expectancy

PALLONI, ALBERTO; AYUSO, MERCEDES; GUILLÉN, MONTSERRAT; MONTEVERDE, MALENA; WHITE, ROBERT

Philadelphia

Congreso; Population Association of America Annual Meeting; 2005

Population Association of America

We evaluate the accuracy of alternative methods to assess disability-adjusted life expectancies among elderly people. We pose a three-state model (healthy(H), disabled(D), dead(DD)) with four transitions (H to D, D to DD, H to DD, and D to H) and use Montecarlo simulations to generate individual trajectories. The rates in the simulations reflect the experience of the US population (HRS). We apply three methods to estimate disability-adjusted life expectancy, each using only partially observed information: (a) Sullivan?s calculations; (b) increment-decrement tables; (c) a new procedure to estimate transition probabilities H to D from observed prevalence and overall mortality. We compare resulting estimates with the true values embedded in simulations under conditions departing from assumptions invoked by the methods, including functional forms, lack of stationarity, mortality differentials between disability status, and intensity of the transition D to H. Finally, we assess the impact of these errors for elderly care costs calculations.