Background: We investigated whether having a regular health care provider for diabetes was related to the intensity of care, use of preventive services, or glycemic control in a well-defined population of adults with diabetes.
Methods: Adults with diabetes who were continuously enrolled in a health maintenance organization (HMO) for 1 year were identified by diagnostic and pharmacy databases (estimated sensitivity = 0.91, positive predictive value = 0.94). In a stratified random sample, 1828 patients were sent a survey by mail that had a corrected response rate of 85.6%. Further data on utilization of services and glycosylated hemoglobin values were obtained from administrative databases and linked to survey responses.
Results: HMO members who reported having a regular health care provider (RP) for their diabetes (N = 1243) were comparable with those (N = 144) who denied having such a provider (NRP) in age, race, sex, comorbidity, and years of education, but had longer-duration diabetes (10.9 years vs 8.3 years; P = .002). After adjusting for age, sex, education level, duration of diabetes, and type of HMO clinic (owned vs contracted), RP subjects were more likely than NRPs (all P < .001) to follow a special diet for patients with diabetes (55% vs 33%), regularly monitor glucose levels at home (68% vs 47%), have greater frequency of glycosylated hemoglobin (Hb A1c) testing (65% vs 38%), have more foot examinations (42% vs 17%), have recommended cholesterol checks (77% vs 63%), and have had a recent preventive examination (86% vs 68%). Smaller differences favoring having a regular provider were noted for insulin use (48% vs 33%, odds ratio [OR] = 1.71, P = .013), for an influenza immunization within 1 year (65% vs 51%, P = .029), and for dilated retinal examinations (64% vs 51%, P < .027). No differences between groups were noted for dental checkups (69% vs 67%, P = .724) or likelihood of endocrinology referral (17% vs 10%, P = .104). Mean Hb A1c level was 8.2% (normal is < 6.1%) in the RP group and 8.6% in the NRP group (P = .182). Twelve percent of RPs and 24% of NRPs had an Hb A1c level of greater than 10% (chi 2 = 3.7, OR = 0.48, P = .05) after adjusting for age, sex, duration of diabetes, and education level.
Conclusions: After adjustment for case mix, patients with diabetes who identified a regular primary health care provider for their diabetes were more likely to receive most recommended elements of diabetes care and to have better glycemic control than patients without such a provider. This effect was partially, but not completely, mediated by a higher number of clinic visits for those with a regular health care provider. Innovators seeking to improve diabetes care should be mindful of the relationship between having a regular primary health care provider and the quality of diabetes care.