ORIGINAL CONTRIBUTION Development and Validation of a Prognostic Index for 4-Year Mortality in Older Adults

PROGNOSTIC INFORMATION ISvaluable to many of the stake-holders in the US health caresystem. For patients and care-givers, prognostic information is needed to inform clinical decisionmaking.1 For example, patients with limited life ex-pectancy may benefit more from ad-vance care planning and discussions on the goals of care.2,3 Older patients with better than average life expectancymay be more likely to benefit from cancer screening since recent guidelines sug-gest clinicians target screening in the el-derly to those with life expectancies greater than 5 years.4-6 For policymak-ers, prognostic information is essential when comparing the quality of care be-tween different health care organiza-tions, such as hospitals and insurance plans. Accurate risk adjustment levels the playing field by accounting for the differences in health status of the un-derlying populations making fair com-parisons between health care organiza-tions possible. Finally, prognostic information is essential for epidemio-logical studies.7Observational studies re-quire accurate risk adjustment so that baseline differences donot confound the relationship between the risk factor of interest and the outcome. Despite the clinical, policy, and epi-demiological importance of prognostic information, thereare fewprognostic in-dexes thatcaneasilybeused in largeseg-ments of thepopulation.Manyhave fo-cusedon specific segmentsof thepopu-lation such as hospitalized elders8-10 or veterans.11Other indexes have focused onsingledomainsofrisk,suchascomor-bidity12or function.13,14Finally, somein-dexesrequire laboratoryorperformanc