TUESDAY, March 15 (HealthDay News) -- There is an inverse relationship between the regional frequency of diagnoses for chronic conditions and the case-fatality rate among fee-for-service Medicare beneficiaries, according to a study published in the March 16 issue of the Journal of the American Medical Association.
H. Gilbert Welch, M.D., M.P.H., from the U.S. Department of Veterans Affairs Medical Center in White River Junction, Vt., and colleagues determined the association between frequency of diagnoses for nine chronic conditions in different geographic areas of the United States and case-fatality rate among 5,153,877 fee-for-service Medicare beneficiaries in 2007. Diagnoses occurred in 306 hospital referral regions (HRRs), which were divided into quintiles based on diagnosis frequency.
The investigators found that the diagnosis frequency of chronic conditions varied across HRRs from 0.58 in Grand Junction, Colo., to 1.23 in Miami, Fla., per Medicare beneficiary. Among patients diagnosed with zero, one, two, or three chronic diseases, the corresponding case-fatality rates were 16, 45, 93, and 154 per 1,000. Case fatality rates decreased progressively with an increase in regional diagnosis frequency. For diagnosis of one chronic condition, the case fatality rate varied from 51 per 1,000 in the lowest quintile to 38 per 1,000 in the highest quintile (relative rate, 0.74). Corresponding variation for diagnosis of three conditions was 168 and 137 per 1,000 (relative rate, 0.81).
"Among patient subgroups with a given number of chronic conditions, there was a consistent stepwise decrement in case fatality as diagnosis frequency increased," the authors write.