Life expectancy estimation with breast cancer: bias of the declining exponential function and an alternative to its use.
| Autor: | Holland RR; Office of Health Promotion Research, Burlington, Vermont 05401-3444, USA. rholland@sover.net, Ellis CA, Geller BM, Plante DA, Secker-Walker RH |
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| Jazyk: | angličtina |
| Zdroj: | Medical decision making : an international journal of the Society for Medical Decision Making [Med Decis Making] 1999 Oct-Dec; Vol. 19 (4), pp. 385-93. |
| DOI: | 10.1177/0272989X9901900406 |
| Abstrakt: | Background: Life expectancy gain (LEG) is an outcome measure commonly estimated with a declining exponential function in a Markov model. The accuracy of such estimates has not been objectively evaluated. Purpose: To compare LEGs from declining exponential function estimates with those calculated from population data, using published screening mammography studies as examples. Method: SEER-based population data are used to compare LEG calculation with declining exponential function estimation and empiric population data in a new model, the "nested" Markov. Results: Analyses of the LEG of mammographic screening based on the declining exponential function significantly overestimate LEGs for younger women and underestimate them for older women. Because of offsetting errors, all-age analyses paradoxically appear accurate. Conclusion: Declining exponential function estimates of LEGs for chronic diseases with low mortality rates and long time horizons are liable to significant bias, especially with limited age cohorts. |
| Databáze: | MEDLINE |
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