Results
According to our criteria, a total of 30,589 patients (56.4% women) representing 8.4% of all Medicare patients had diabetes. These patients made 392,831 outpatient visits to physicians during 1994, for an average of 12.8 visits per person. A diagnosis of diabetes was recorded for 42.7% of all outpatient visits by patients with diabetes.
Urban patients made more ambulatory visits overall than their rural counterparts, although there was no significant difference in the number of visits for diabetes. Patients living in small remote rural communities made significantly fewer ambulatory visits than patients living in any other place. The overall illness severity mirrored the number of ambulatory visits: 55.1% of urban patients and those living in large remote areas had 4 or more major chronic conditions; 51.3% of the group living in the small remote rural areas had the same burden of disease (P <.01).
Geographic location had a profound effect on where patients received their care. Urban patients received virtually all their outpatient care in their local urban areas (97.9%). Patients living in large rural communities also received most of their outpatient care in their own community. When patients in these communities did travel for care, they usually went to an urban community.
The small rural communities were much less self-sufficient, with almost half of all outpatient visits occurring outside the local community. Patients from small towns adjacent to cities went to urban areas. Patients from the remote small communities were more likely to get care in large rural communities; a substantial number, however, went to urban areas.
Generalists provided most of the care for patients with diabetes Table 1. Family physicians and general internists accounted for 62.4% of all visits coded for diabetes. The smaller and more remote the area, the higher the proportion of visits to family physicians. Endocrinologists, who handle more than 11% of the outpatient diabetic visits of the urban elderly, were seen for only 3% of the diabetic visits of those living in small remote communities . Urban patients were much more likely to consult an endocrinologist than their rural counterparts; 16.3% of urban patients visited an endocrinologist at least once during the year, compared with 6.9% of rural patients.
Adherence to Guidelines
The majority of patients had their cholesterol and glycated hemoglobin measured and their eyes examined at least once during the study year Table 2, although only 27.5% of patients had all 3 determinations performed. Urban patients were significantly more likely to have their glycated hemoglobin and cholesterol levels measured than rural patients, although the differences were small. Most patients who had glycated hemoglobin measured had either 1 or 2 such tests during the study year, with 31.3% of patients receiving 2 glycated hemoglobin determinations during the year.
Patients living in large remote rural communities were significantly more likely to have received all 3 of the core diabetes quality measures than patients in any of the other areas. By contrast, patients living in large rural communities adjacent to metropolitan areas were much less likely to have a glycated hemoglobin determination or an eye examination. Small rural towns had essentially identical screening rates, independent of their proximity to an urban area.
The specialty of the physicians was not associated with differences in adherence to screening guidelines, with one exception. Patients who saw an endocrinologist at least once during the year were much more likely to have received a glycated hemoglobin determination. Of patients who saw an endocrinologist, 77.9% received this test versus 51.0% of the patients with diabetes who had not seen an endocrinologist. The proportion of eye examinations and cholesterol measurements were also higher for patients who consulted an endocrinologist, although the differences are not as large as for glycated hemoglobin tests.
We used logistic regression to test the independent effect of patient residence on the likelihood of receiving the recommended tests.*Table w1 Patient residence is associated with significant differences in the likelihood that a patient received a glycated hemoglobin test. Patients living in large rural communities adjacent to metropolitan areas were significantly less likely to have a glycated hemoglobin determination than patients living in all other locations, even after controlling for sociodemographic factors, illness severity, and physician specialty. By contrast, patients living in large remote areas were much more likely to have received the test. Patients living in small remote rural areas received the test at a rate similar to that of patients living in urban areas, all other factors being equal. The single variable with the greatest independent effect was whether the patient saw an endocrinologist during the year.