Having a larger primary-care workforce was associated with fewer hospitalizations for Medicare beneficiaries—though measurement of the workforce was problematic and differences in mortality rates were not significantly associated with the number of available adult primary-care doctors, according to a study in the Journal of the American Medical Association.
Study examines impact of primary-care workforce size on hospitalization, mortality rates
Researchers from the Dartmouth Medical School, Hanover, N.H., and the University of Toronto used two measures to gauge the primary-care workforce in ZIP code-defined service areas: family physicians and general internists listed in the AMA Masterfile and an estimate of full-time equivalent adult primary-care physicians based on Medicare data for office- and clinic-based claims. After adjusting for age, race, sex and ZIP code median household income, the researchers examined the link between an area's primary-care workforce and the rates of mortality and largely avoidable hospitalization for nine chronic conditions—including cancer, congestive heart failure, dementia, diabetes, kidney failure and severe liver disease—and the presence of multiple conditions.
Using the AMA Masterfile, areas with the largest adult primary-care workforce had almost 6% fewer avoidable—or “ambulatory care sensitive” hospitalizations—than areas with the lowest workforce: 74.9 hospitalizations per 1,000 beneficiaries compared with 79.61. But there was less than a 2% difference in mortality rates: 5.38 deaths per 100 beneficiaries in areas with the largest adult primary-care workforce compared with 5.47 in areas with the smallest. Also, in areas with the larger workforce, $8,722 was spent per Medicare beneficiary compared with $8,765 in the areas with the smallest.
The researchers, however, noted that use of the AMA Masterfile did not accurately measure the adult primary-care workforce as some were not providing fee-for-service care to Medicare beneficiaries or were providing inpatient or specialty care. Further analysis found that “a significant proportion of the physicians delivering primary-care services as per Medicare were not classified as office-based primary care physicians in the AMA Masterfile,” according to the report.
Differences were greater using the FTE estimates from Medicare claims. In areas with the highest adult primary-care FTEs, mortality rates were almost 5.5% lower compared to the areas with the lowest: 5.19 vs. 5.49 deaths per 100 beneficiaries. And the avoidable hospitalization rate was 8.7% lower: 72.53 vs. 79.48 per 1,000 beneficiaries. Spending, however, was 1% higher in areas with more FTE adult primary-care physicians: $8,857 vs. $8,769 per beneficiary.
The researchers calculated that, if all areas had the same number of adult primary doctors in the AMA Masterfile as the areas with the largest workforce, there would be 670 fewer deaths, 159,144 fewer ambulatory care sensitive hospitalizations. If all areas increased to the highest level of primary-care FTEs, they calculated there would be 48,398 fewer deaths and 436,002 fewer hospitalizations.
“Our study offers the cautionary note that having more physicians trained in primary care practicing in an area, by itself, does not ensure substantially lower mortality, fewer hospitalizations, or lower costs,” the report concluded. “Increasing the training capacity of family medicine and internal medicine may have disappointing patient benefits if the resulting physicians are primary care in name only.”
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