Computational and Mathematical Methods in Medicine
Volume 2011 (2011), Article ID 857892, 14 pages
doi:10.1155/2011/857892
Research Article

Medical Cost Trajectories and Onsets of Cancer and NonCancer Diseases in US Elderly Population

1Center for Population Health and Aging, Duke University, Durham, NC 27708, USA
2Duke Cancer Institute, Duke University, Durham, NC 27705, USA

Received 4 January 2011; Accepted 3 March 2011

Academic Editor: Thierry Busso

Copyright © 2011 Igor Akushevich et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Time trajectories of medical costs-associated with onset of twelve aging-related cancer and chronic noncancer diseases were analyzed using the National Long-Term Care Survey data linked to Medicare Service Use files. A special procedure for selecting individuals with onset of each disease was developed and used for identification of the date at disease onset. Medical cost trajectories were found to be represented by a parametric model with four easily interpretable parameters reflecting: (i) prediagnosis cost (associated with initial comorbidity), (ii) cost of the disease onset, (iii) population recovery representing reduction of the medical expenses associated with a disease since diagnosis was made, and (iv) acquired comorbidity representing the difference between post- and pre diagnosis medical cost levels. These parameters were evaluated for the entire US population as well as for the subpopulation conditional on age, disability and comorbidity states, and survival (2.5 years after the date of onset). The developed approach results in a family of new forecasting models with covariates.