Primary care practices and determinants of optimal anticoagulation management in a collaborative care model

Abstract

Background: In a collaborative care model (CCM) for managing oral anticoagulant therapy, patients are followed at a pharmacist-managed anticoagulation service and, once stabilized, are transferred to their primary care physician. The objective of this study was to describe physicians' clinical practices and the practice characteristics associated with better international normalized ratio (INR) control in a CCM.

Methods: A telephone questionnaire about their practices was administered to 121 physicians exposed to a CCM. The physicians followed 121 patients for a mean of 14.5 weeks. The percentage of time within the exact INR target range was computed and dichotomized (> or = or < median time within target range). Determinants of better INR control were identified using logistic regression models.

Results: The survey revealed that, after discharge from the pharmacist-managed anticoagulation service, patients are followed mainly by physicians and their secretaries. Physicians do not often consult other health professionals. Few report using technological resources to obtain INR results (39.7%), document medical follow-up (6.6%), or detect drug (32.2%) and food (9.9%) interactions. The median percentage of time within the exact INR target range was 84%. Determinants of better INR control include using computerized support to monitor patients (odds ratio [OR] 9.16, 95% CI 1.77-47.4) and detect drug interactions (OR 3.49, 95% CI 1.71-7.10) and consulting specialists (OR 5.92, 95% CI 1.49-32.48).

Conclusions: Primary care physicians are poorly supported by technological and human resources to monitor patients on oral anticoagulant. Even in a CCM, interprofessional collaboration and better technological support may be associated with optimal INR control.