Predicting 5- and 10-Year Mortality Risk in Older Adults with Diabetes Mellitus

OBJECTIVE: Several diabetes clinical practice guidelines suggest that treatment goals may be modified in older adults based on comorbidities, complications and life expectancy. The long-term benefits of treatment intensification may not outweigh short-term risks for patients with limited life expectancy. Due to the uncertainty of determining life expectancy for individual patients, we sought to develop and validate prognostic indices for mortality in older adults with diabetes.

RESEARCH DESIGN AND METHODS: We used a prevalence sample of Veterans with diabetes who were aged ≥65 years on January 1, 2006 (n=275,190). Administrative data were queried for potential predictors that included patient demographics, comorbidities and procedure codes, lab values and anthropomorphic measurements, medication history, and previous health services utilization. Logistic least absolute shrinkage and selection operator (LASSO) regressions were employed to identify variables independently associated with mortality. The resulting odds ratios were then weighted to create prognostic indices of mortality over 5 and 10 years.

RESULTS: Thirty-three predictors of mortality were identified: four demographic variables, prescriptions for insulin or sulfonylureas, five biomarkers, previous outpatient and inpatient utilization, and twenty comorbidities/procedures. The prognostic indices showed good discrimination, with c-statistics of 0.74 and 0.76 for 5 and 10-year mortality, respectively. The indices also demonstrated excellent agreement between observed outcome and predictions, with calibration slopes of 1.01 for both 5 and 10-year mortality.

CONCLUSIONS: Prognostic indices obtained from administrative data can predict 5- and 10-year mortality in older adults with diabetes. Such a tool may enable clinicians and patients to develop individualized treatment goals that balance risks and benefits of treatment intensification.