Role of organizational factors in poor blood pressure control in patients with type 2 diabetes: the QuED Study Group--quality of care and outcomes in type 2 diabetes

Abstract

Background: A large body of evidence supports the need for reducing the cardiovascular burden of diabetes. Only indirect and occasional data describe the adequacy of routine management of hypertension in patients with diabetes. The aim of this study was to explore the interplay of some potential key determinants of quality of antihypertensive care, including the settings, physicians' beliefs about blood pressure (BP) control, and patient-related factors.

Methods: We evaluated physicians' beliefs about BP control using questionnaire responses at study entry. A sample of 3449 patients with type 2 diabetes mellitus, of whom 1782 (52%) were considered to have hypertension, was recruited by 212 physicians practicing in 125 diabetes outpatients clinics (DOCs) and 106 general practitioners (GPs). We evaluated the type and number of antihypertensive agents used and the BP values at study entry and after 1 year of follow-up. We used multilevel analysis to investigate correlates of poor BP control (> or =160/90 mm Hg).

Results: Only 16% of GPs and 14% of DOC physicians targeted BP values of less than 130/85 mm Hg. At study entry, 6% of the patients had values below 130/85 mm Hg, whereas 52% showed values of 160/90 mm Hg or greater. Only 12% of subjects were treated with more than 2 drugs at study entry, compared with 16% at the 1-year follow-up (P =.001). Multilevel analysis showed that patients attending DOCs had a more than 2-fold increased risk for inadequate BP control, compared with those treated by GPs. The risk for poor BP control was 2 times higher for patients treated by male physicians compared with those treated by female physicians, and it was halved when the physician responsible for the diabetes care specialized in diabetology or endocrinology.

Conclusion: In a model situation of comorbidity, the overall quality of care depends on structural and organizational factors, which are likely to be more influential than existing guidelines.