Roger A. Rosenblatt, MD, MPH

It is difficult to provide high-quality care to elderly patients with diabetes, and this task may be even more problematic in rural areas.¹ There are fewer physicians in such areas, and chronic conditions may get short shrift from both physicians and patients.² The relative shortage of specialists in rural areas may make it more difficult for physicians and their patients to get some of the specialized services they may need.³ Knowledge about advances in diabetic care may diffuse more slowly to these areas, making it less likely that physicians and patients will be aware of or adhere to published guidelines.

Previous studies have shown that the rural elderly-particularly those living in the smallest and most remote areas-make fewer office visits to physicians.² These same patients are more likely to see family physicians-and less likely to visit specialists-than their urban counterparts.⁴ It is not known whether this is true specifically of patients with diabetes, and the impact of these patterns on adherence to generally accepted guidelines is unknown.

We examined rural-urban differences in the care of persons with diabetes to determine what kinds of locations promote high-quality care. It may be possible to improve diabetes care either through further training of generalists or by providing opportunities for formal consultation with relevant specialists within the communities where these patients live.

Methods

Our study was based on data from the Medicare program for Washington state in 1994. During that year 362,145 Medicare recipients 65 years and older used medical care, did not belong to a capitated plan, had continuous Medicare coverage, received all their medical care in Washington State, and were alive at the end of the year.

For the purposes of our study, a diabetic visit is defined as any visit to a physician in an ambulatory setting where that physician entered any of the following International Classification of Diseases–ninth revision codes as a diagnosis: 250.XX (diabetes), 362.01 and 262.02 (diabetic retinopathy), 357.2 (diabetic polyneuropathy), or 366.41 (diabetic cataract). Patients are considered to have diabetes if they have at least 2 physician encounters for 1 of these codes in an ambulatory setting on separate days.

Patient residence was determined by the residential ZIP Code, and all patients were assigned as being rural or urban based on their residence.⁵ Rural communities were considered to be large if they had hospitals with more than 100 beds. The identity of the physician was determined from the unique physician identification number (UPIN) assigned by Medicare. UPINs were present 99.1% of the time, and specialty could be determined for 99.0% of these physicians.

Quality of Care Measurements

We created a core quality index of items that most authoritative sources agree should be performed regularly in patients with diabetes^6-9 and that can be identified using the Medicare Part B claims file.^10-12 The core quality index included a glycated hemoglobin determination, cholesterol measurement, and an eye examination by either an ophthalmologist or an optometrist. A service was considered to have been performed if a claim for any of the above items-or for a multi-test procedure of which that item is a part-was submitted by any provider during the 1994 study year.

Analytic Approach

We used the ambulatory care group (ACG) case-mix classification system to control for patient comorbidities.^13,14 Confidence intervals were calculated for independent and control variables in the logistic regression. Chi-square tests were used to compare results across different geographic areas. Because of multiple comparisons, we only report differences significant at the .01 level.

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.

A similar pattern prevails when using the core diabetes quality index in a multiple linear regression (not tabled). Study variables explain 18.18% of the variance in the index value. All 4 of the rural residential variables were statistically significant; patients living in remote large rural areas had a greater likelihood of receiving the recommended tests after controlling for potential confounders, while patients living in other types of rural areas were less likely to receive the tests.

Discussion

The quality of outpatient care for elderly persons with diabetes leaves much to be desired.^10-12,15 On a national level, only 21% of patients received a glycated hemoglobin determination in 1994, perhaps the best single summary of diabetic control available to physicians.^10,11 In our study of Washington for the same year, a much higher proportion of patients received this test, suggesting the existence of major regional differences. Yet even in our study, almost half of patients with a diagnosis of diabetes did not receive a glycated hemoglobin determination even though Medicare reimburses separately for this test. Only 27.5% received all 3 of the tests recommended by authoritative national organizations during the study year.

The location of the patients’ community affects their likelihood of receiving the recommended screening tests. Patients living in large rural communities remote from cities were significantly more likely to receive the recommended services than their urban counterparts; patients living in other rural locations were less likely to receive these services.

What might explain these findings? One contributing factor is the relative unavailability of endocrinologists in many rural communities. Rural patients who saw an endocrinologist at least once during the year were almost twice as likely to have had a glycated hemoglobin determination, probably because ordering such a test is part of the routine when endocrinologists see a new patient with diabetes.¹⁶ Only 24.6% of the visits to an endocrinologist occurred within the rural area where the patient lived, since most endocrinologists practice in urban areas. It is likely that this access barrier explains the much lower rate at which rural patients see endocrinologists and contributes to the lower rate of appropriate testing.

But this is not the only factor. There are very few endocrinologists in the state of Washington (69 in our study), and most diabetic care is provided by primary care physicians.¹⁷ The highest rate of guideline adherence occurs in large remote rural communities—communities that have endocrinologists but where the rate at which patients visit these specialists is still less than half of that in urban communities. It may be that large rural towns represent the best of both worlds: vibrant, rapidly growing communities with an adequate supply of both generalist and specialist physicians that serve as regional referral centers for surrounding rural towns.

Limitations

These data are based on the elderly Medicare population in Washington who are not members of managed care organizations. Managed care penetration in 1994 was relatively low (12% of the entire population), but was higher in urban than in rural areas. With the increased attention that managed care pays to adherence to guidelines, it is possible that the true rate of urban compliance is higher than we reported. The rates in rural areas would be little affected by this limitation. Patterns of care may also be different for younger people, irrespective of insurance coverage. Care may also have improved since 1994.

Also, Medicare’s data systems are primarily mechanisms to ensure accurate billing and payment; they were not designed as research tools. However, previous work by Weiner and colleagues¹² shows that the Medicare data were of generally good quality. Finally, our study relied entirely on process of care as a surrogate for medical care quality. Although there is general consensus that the process measures studied here are desirable in the care of patients with diabetes, we do not know whether patients who received these tests had better outcomes.

Conclusions

The results of our study demonstrate that the quality of care received by Medicare patients in Washington in 1994 was better in some important respects than that received in other parts of the country. Although there is still significant room for improvement, the fact that there is marked regional variation suggests that physicians can make meaningful improvements in the quality of care.^18,19 It would be useful to identify specific communities where quality of care indicators were suboptimal and design educational efforts for patients and care providers. Perhaps using Medicare data to provide physician scorecards would improve adherence.

Adherence to quality standards was not uniform across rural communities. Rural communities in counties adjacent to metropolitan areas had significantly lower quality-of-care measures than people living in nearby urban areas. Perhaps there are unmeasured socioeconomic or medical practice factors among these populations that explain this lower level of adherence to established standards, even after correcting for the confounding variables that we were able to measure. It would be worth embarking on a systematic exploration of the clinical, social, and organizational factors that led to this relatively substandard experience that has been noted for other defined populations.²⁰

The fact that the highest-quality care occurs in large remote rural communities may contain some lessons for the optimal organization of health services. These are communities that have moderate-sized hospitals, a balanced mix of generalists and specialists, and population sizes between 10,000 and 50,000 people. There may be advantages to living in areas such as these where patients are not exposed to the potentially deleterious effect of too few physicians or fragmentation of services amidst a surplus of specialists. Future studies are needed to determine if these findings can be generalized to the care of other patients and other conditions.

Acknowledgments

Our work was funded by a grant from the Federal Office of Rural Health Policy, the Robert Wood Johnson Foundation, and the Agency for Health Care Policy and Research.

Related Resources

• American Diabetes Association www.diabetes.org Definitive source of patient-centered information about diabetes and its treatment.
• Canadian Diabetes Association http://www.diabetes.ca/ Information on insulin, nutrition, research, complications of diabetes, juvenile diabetes and other disease-related issues. Resources for patients and physicians.
• National Institute of Diabetes and Digestive Diseases and Kidney Diseases http://www.niddk.nih.gov/ Health education programs and publications on diabetes for patients, Information on clinical trials and research funding opportunities for physicians, faculty and researchers.

It is difficult to provide high-quality care to elderly patients with diabetes, and this task may be even more problematic in rural areas.¹ There are fewer physicians in such areas, and chronic conditions may get short shrift from both physicians and patients.² The relative shortage of specialists in rural areas may make it more difficult for physicians and their patients to get some of the specialized services they may need.³ Knowledge about advances in diabetic care may diffuse more slowly to these areas, making it less likely that physicians and patients will be aware of or adhere to published guidelines.

Previous studies have shown that the rural elderly-particularly those living in the smallest and most remote areas-make fewer office visits to physicians.² These same patients are more likely to see family physicians-and less likely to visit specialists-than their urban counterparts.⁴ It is not known whether this is true specifically of patients with diabetes, and the impact of these patterns on adherence to generally accepted guidelines is unknown.

We examined rural-urban differences in the care of persons with diabetes to determine what kinds of locations promote high-quality care. It may be possible to improve diabetes care either through further training of generalists or by providing opportunities for formal consultation with relevant specialists within the communities where these patients live.

Methods

Our study was based on data from the Medicare program for Washington state in 1994. During that year 362,145 Medicare recipients 65 years and older used medical care, did not belong to a capitated plan, had continuous Medicare coverage, received all their medical care in Washington State, and were alive at the end of the year.

For the purposes of our study, a diabetic visit is defined as any visit to a physician in an ambulatory setting where that physician entered any of the following International Classification of Diseases–ninth revision codes as a diagnosis: 250.XX (diabetes), 362.01 and 262.02 (diabetic retinopathy), 357.2 (diabetic polyneuropathy), or 366.41 (diabetic cataract). Patients are considered to have diabetes if they have at least 2 physician encounters for 1 of these codes in an ambulatory setting on separate days.

Patient residence was determined by the residential ZIP Code, and all patients were assigned as being rural or urban based on their residence.⁵ Rural communities were considered to be large if they had hospitals with more than 100 beds. The identity of the physician was determined from the unique physician identification number (UPIN) assigned by Medicare. UPINs were present 99.1% of the time, and specialty could be determined for 99.0% of these physicians.

Quality of Care Measurements

We created a core quality index of items that most authoritative sources agree should be performed regularly in patients with diabetes^6-9 and that can be identified using the Medicare Part B claims file.^10-12 The core quality index included a glycated hemoglobin determination, cholesterol measurement, and an eye examination by either an ophthalmologist or an optometrist. A service was considered to have been performed if a claim for any of the above items-or for a multi-test procedure of which that item is a part-was submitted by any provider during the 1994 study year.

Analytic Approach

We used the ambulatory care group (ACG) case-mix classification system to control for patient comorbidities.^13,14 Confidence intervals were calculated for independent and control variables in the logistic regression. Chi-square tests were used to compare results across different geographic areas. Because of multiple comparisons, we only report differences significant at the .01 level.

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.

A similar pattern prevails when using the core diabetes quality index in a multiple linear regression (not tabled). Study variables explain 18.18% of the variance in the index value. All 4 of the rural residential variables were statistically significant; patients living in remote large rural areas had a greater likelihood of receiving the recommended tests after controlling for potential confounders, while patients living in other types of rural areas were less likely to receive the tests.

Discussion

The quality of outpatient care for elderly persons with diabetes leaves much to be desired.^10-12,15 On a national level, only 21% of patients received a glycated hemoglobin determination in 1994, perhaps the best single summary of diabetic control available to physicians.^10,11 In our study of Washington for the same year, a much higher proportion of patients received this test, suggesting the existence of major regional differences. Yet even in our study, almost half of patients with a diagnosis of diabetes did not receive a glycated hemoglobin determination even though Medicare reimburses separately for this test. Only 27.5% received all 3 of the tests recommended by authoritative national organizations during the study year.

The location of the patients’ community affects their likelihood of receiving the recommended screening tests. Patients living in large rural communities remote from cities were significantly more likely to receive the recommended services than their urban counterparts; patients living in other rural locations were less likely to receive these services.

What might explain these findings? One contributing factor is the relative unavailability of endocrinologists in many rural communities. Rural patients who saw an endocrinologist at least once during the year were almost twice as likely to have had a glycated hemoglobin determination, probably because ordering such a test is part of the routine when endocrinologists see a new patient with diabetes.¹⁶ Only 24.6% of the visits to an endocrinologist occurred within the rural area where the patient lived, since most endocrinologists practice in urban areas. It is likely that this access barrier explains the much lower rate at which rural patients see endocrinologists and contributes to the lower rate of appropriate testing.

But this is not the only factor. There are very few endocrinologists in the state of Washington (69 in our study), and most diabetic care is provided by primary care physicians.¹⁷ The highest rate of guideline adherence occurs in large remote rural communities—communities that have endocrinologists but where the rate at which patients visit these specialists is still less than half of that in urban communities. It may be that large rural towns represent the best of both worlds: vibrant, rapidly growing communities with an adequate supply of both generalist and specialist physicians that serve as regional referral centers for surrounding rural towns.

Limitations

These data are based on the elderly Medicare population in Washington who are not members of managed care organizations. Managed care penetration in 1994 was relatively low (12% of the entire population), but was higher in urban than in rural areas. With the increased attention that managed care pays to adherence to guidelines, it is possible that the true rate of urban compliance is higher than we reported. The rates in rural areas would be little affected by this limitation. Patterns of care may also be different for younger people, irrespective of insurance coverage. Care may also have improved since 1994.

Also, Medicare’s data systems are primarily mechanisms to ensure accurate billing and payment; they were not designed as research tools. However, previous work by Weiner and colleagues¹² shows that the Medicare data were of generally good quality. Finally, our study relied entirely on process of care as a surrogate for medical care quality. Although there is general consensus that the process measures studied here are desirable in the care of patients with diabetes, we do not know whether patients who received these tests had better outcomes.

Conclusions

The results of our study demonstrate that the quality of care received by Medicare patients in Washington in 1994 was better in some important respects than that received in other parts of the country. Although there is still significant room for improvement, the fact that there is marked regional variation suggests that physicians can make meaningful improvements in the quality of care.^18,19 It would be useful to identify specific communities where quality of care indicators were suboptimal and design educational efforts for patients and care providers. Perhaps using Medicare data to provide physician scorecards would improve adherence.

Adherence to quality standards was not uniform across rural communities. Rural communities in counties adjacent to metropolitan areas had significantly lower quality-of-care measures than people living in nearby urban areas. Perhaps there are unmeasured socioeconomic or medical practice factors among these populations that explain this lower level of adherence to established standards, even after correcting for the confounding variables that we were able to measure. It would be worth embarking on a systematic exploration of the clinical, social, and organizational factors that led to this relatively substandard experience that has been noted for other defined populations.²⁰

The fact that the highest-quality care occurs in large remote rural communities may contain some lessons for the optimal organization of health services. These are communities that have moderate-sized hospitals, a balanced mix of generalists and specialists, and population sizes between 10,000 and 50,000 people. There may be advantages to living in areas such as these where patients are not exposed to the potentially deleterious effect of too few physicians or fragmentation of services amidst a surplus of specialists. Future studies are needed to determine if these findings can be generalized to the care of other patients and other conditions.

Acknowledgments

Our work was funded by a grant from the Federal Office of Rural Health Policy, the Robert Wood Johnson Foundation, and the Agency for Health Care Policy and Research.

Related Resources

• American Diabetes Association www.diabetes.org Definitive source of patient-centered information about diabetes and its treatment.
• Canadian Diabetes Association http://www.diabetes.ca/ Information on insulin, nutrition, research, complications of diabetes, juvenile diabetes and other disease-related issues. Resources for patients and physicians.
• National Institute of Diabetes and Digestive Diseases and Kidney Diseases http://www.niddk.nih.gov/ Health education programs and publications on diabetes for patients, Information on clinical trials and research funding opportunities for physicians, faculty and researchers.

It is difficult to provide high-quality care to elderly patients with diabetes, and this task may be even more problematic in rural areas.¹ There are fewer physicians in such areas, and chronic conditions may get short shrift from both physicians and patients.² The relative shortage of specialists in rural areas may make it more difficult for physicians and their patients to get some of the specialized services they may need.³ Knowledge about advances in diabetic care may diffuse more slowly to these areas, making it less likely that physicians and patients will be aware of or adhere to published guidelines.

Previous studies have shown that the rural elderly-particularly those living in the smallest and most remote areas-make fewer office visits to physicians.² These same patients are more likely to see family physicians-and less likely to visit specialists-than their urban counterparts.⁴ It is not known whether this is true specifically of patients with diabetes, and the impact of these patterns on adherence to generally accepted guidelines is unknown.

We examined rural-urban differences in the care of persons with diabetes to determine what kinds of locations promote high-quality care. It may be possible to improve diabetes care either through further training of generalists or by providing opportunities for formal consultation with relevant specialists within the communities where these patients live.

Methods

Our study was based on data from the Medicare program for Washington state in 1994. During that year 362,145 Medicare recipients 65 years and older used medical care, did not belong to a capitated plan, had continuous Medicare coverage, received all their medical care in Washington State, and were alive at the end of the year.

For the purposes of our study, a diabetic visit is defined as any visit to a physician in an ambulatory setting where that physician entered any of the following International Classification of Diseases–ninth revision codes as a diagnosis: 250.XX (diabetes), 362.01 and 262.02 (diabetic retinopathy), 357.2 (diabetic polyneuropathy), or 366.41 (diabetic cataract). Patients are considered to have diabetes if they have at least 2 physician encounters for 1 of these codes in an ambulatory setting on separate days.

Patient residence was determined by the residential ZIP Code, and all patients were assigned as being rural or urban based on their residence.⁵ Rural communities were considered to be large if they had hospitals with more than 100 beds. The identity of the physician was determined from the unique physician identification number (UPIN) assigned by Medicare. UPINs were present 99.1% of the time, and specialty could be determined for 99.0% of these physicians.

Quality of Care Measurements

We created a core quality index of items that most authoritative sources agree should be performed regularly in patients with diabetes^6-9 and that can be identified using the Medicare Part B claims file.^10-12 The core quality index included a glycated hemoglobin determination, cholesterol measurement, and an eye examination by either an ophthalmologist or an optometrist. A service was considered to have been performed if a claim for any of the above items-or for a multi-test procedure of which that item is a part-was submitted by any provider during the 1994 study year.

Analytic Approach

We used the ambulatory care group (ACG) case-mix classification system to control for patient comorbidities.^13,14 Confidence intervals were calculated for independent and control variables in the logistic regression. Chi-square tests were used to compare results across different geographic areas. Because of multiple comparisons, we only report differences significant at the .01 level.

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.

A similar pattern prevails when using the core diabetes quality index in a multiple linear regression (not tabled). Study variables explain 18.18% of the variance in the index value. All 4 of the rural residential variables were statistically significant; patients living in remote large rural areas had a greater likelihood of receiving the recommended tests after controlling for potential confounders, while patients living in other types of rural areas were less likely to receive the tests.

Discussion

The quality of outpatient care for elderly persons with diabetes leaves much to be desired.^10-12,15 On a national level, only 21% of patients received a glycated hemoglobin determination in 1994, perhaps the best single summary of diabetic control available to physicians.^10,11 In our study of Washington for the same year, a much higher proportion of patients received this test, suggesting the existence of major regional differences. Yet even in our study, almost half of patients with a diagnosis of diabetes did not receive a glycated hemoglobin determination even though Medicare reimburses separately for this test. Only 27.5% received all 3 of the tests recommended by authoritative national organizations during the study year.

The location of the patients’ community affects their likelihood of receiving the recommended screening tests. Patients living in large rural communities remote from cities were significantly more likely to receive the recommended services than their urban counterparts; patients living in other rural locations were less likely to receive these services.

What might explain these findings? One contributing factor is the relative unavailability of endocrinologists in many rural communities. Rural patients who saw an endocrinologist at least once during the year were almost twice as likely to have had a glycated hemoglobin determination, probably because ordering such a test is part of the routine when endocrinologists see a new patient with diabetes.¹⁶ Only 24.6% of the visits to an endocrinologist occurred within the rural area where the patient lived, since most endocrinologists practice in urban areas. It is likely that this access barrier explains the much lower rate at which rural patients see endocrinologists and contributes to the lower rate of appropriate testing.

But this is not the only factor. There are very few endocrinologists in the state of Washington (69 in our study), and most diabetic care is provided by primary care physicians.¹⁷ The highest rate of guideline adherence occurs in large remote rural communities—communities that have endocrinologists but where the rate at which patients visit these specialists is still less than half of that in urban communities. It may be that large rural towns represent the best of both worlds: vibrant, rapidly growing communities with an adequate supply of both generalist and specialist physicians that serve as regional referral centers for surrounding rural towns.

Limitations

These data are based on the elderly Medicare population in Washington who are not members of managed care organizations. Managed care penetration in 1994 was relatively low (12% of the entire population), but was higher in urban than in rural areas. With the increased attention that managed care pays to adherence to guidelines, it is possible that the true rate of urban compliance is higher than we reported. The rates in rural areas would be little affected by this limitation. Patterns of care may also be different for younger people, irrespective of insurance coverage. Care may also have improved since 1994.

Also, Medicare’s data systems are primarily mechanisms to ensure accurate billing and payment; they were not designed as research tools. However, previous work by Weiner and colleagues¹² shows that the Medicare data were of generally good quality. Finally, our study relied entirely on process of care as a surrogate for medical care quality. Although there is general consensus that the process measures studied here are desirable in the care of patients with diabetes, we do not know whether patients who received these tests had better outcomes.

Conclusions

The results of our study demonstrate that the quality of care received by Medicare patients in Washington in 1994 was better in some important respects than that received in other parts of the country. Although there is still significant room for improvement, the fact that there is marked regional variation suggests that physicians can make meaningful improvements in the quality of care.^18,19 It would be useful to identify specific communities where quality of care indicators were suboptimal and design educational efforts for patients and care providers. Perhaps using Medicare data to provide physician scorecards would improve adherence.

Adherence to quality standards was not uniform across rural communities. Rural communities in counties adjacent to metropolitan areas had significantly lower quality-of-care measures than people living in nearby urban areas. Perhaps there are unmeasured socioeconomic or medical practice factors among these populations that explain this lower level of adherence to established standards, even after correcting for the confounding variables that we were able to measure. It would be worth embarking on a systematic exploration of the clinical, social, and organizational factors that led to this relatively substandard experience that has been noted for other defined populations.²⁰

The fact that the highest-quality care occurs in large remote rural communities may contain some lessons for the optimal organization of health services. These are communities that have moderate-sized hospitals, a balanced mix of generalists and specialists, and population sizes between 10,000 and 50,000 people. There may be advantages to living in areas such as these where patients are not exposed to the potentially deleterious effect of too few physicians or fragmentation of services amidst a surplus of specialists. Future studies are needed to determine if these findings can be generalized to the care of other patients and other conditions.

Acknowledgments

Our work was funded by a grant from the Federal Office of Rural Health Policy, the Robert Wood Johnson Foundation, and the Agency for Health Care Policy and Research.

Related Resources

• American Diabetes Association www.diabetes.org Definitive source of patient-centered information about diabetes and its treatment.
• Canadian Diabetes Association http://www.diabetes.ca/ Information on insulin, nutrition, research, complications of diabetes, juvenile diabetes and other disease-related issues. Resources for patients and physicians.
• National Institute of Diabetes and Digestive Diseases and Kidney Diseases http://www.niddk.nih.gov/ Health education programs and publications on diabetes for patients, Information on clinical trials and research funding opportunities for physicians, faculty and researchers.