Preventable hospitalization among elderly Medicare beneficiaries with type 2 diabetes

To examine the impact of comorbid conditions on preventable hospitalizations among Medicare beneficiaries aged > or =65 years with type 2 diabetes.

Data were drawn from the 1999 Medicare Standard Analytic Files, a 5% nationally representative random sample of Medicare beneficiaries. The analysis sample included 193,556 Medicare beneficiaries aged > or =65 years with type 2 diabetes (ICD-9-CM codes 250.xx) who were enrolled in fee-for-service Medicare. Preventable hospitalization was assessed by measuring ambulatory care-sensitive conditions, an accepted measure of hospitalizations that could have been prevented with appropriate outpatient care. Multivariable analyses controlled for demographics; mortality; renal, ophthalmic, or neurological manifestations of diabetes; type of physician providing the outpatient care; and per capita community-level indicators of income and hospital beds.

Ninety-six percent of beneficiaries in the sample had a comorbidity, and 46% had five or more comorbidities. Among beneficiaries with type 2 diabetes, cardiovascular-related comorbidities were common and accounted for increased odds of preventable hospitalization, controlling for other factors. The likelihood of a preventable hospitalization increased in the presence of a claim for comorbid congestive heart failure, cardiomyopathy, coronary atherosclerosis, hypertension, or cardiac dysrythmias. Noncardiovascular comorbidities associated with a greater likelihood of preventable hospitalization included chronic obstructive pulmonary disease, asthma and lower respiratory disorders, Alzheimer's disease/dementia, personality/anxiety disorders, depression, and osteoporosis. Our data suggest that nearly 7% of all hospitalizations could be avoided.

These findings support the need for improved outpatient care strategies to reduce the impact of comorbidity on unnecessary hospitalization in patients aged > or =65 years with type 2 diabetes.