Determinants of Compliance with Anticoagulation: A Case-Control Study
Section snippets
Study Design
We conducted this study in the Anticoagulation Therapy Unit (ATU) at Massachusetts General Hospital, a large urban teaching hospital. Cases were patients who had demonstrated such severe noncompliance with chronic anticoagulation therapy that it was no longer considered safe. Controls were compliant patients attending the ATU. In-depth telephone surveys were completed with all patients. The study was approved by the Human Subjects Committee of the Institutional Review Board at Massachusetts
Demographic Features
The mean age of noncompliant cases was 53.7 years, significantly younger than the mean age of 68.7 years among controls (P <0.0001)(Table 1). The striking effect of age on compliance is displayed in the Fig. 1 in which the entire sample is divided into six groups based on quintiles of age among the controls. Because the majority of noncompliant cases were clustered in the youngest quintile, we split this group into two deciles. Using the oldest group as a reference category, noncompliant cases
Discussion
Warfarin can be a highly effective preventive therapy but careful patient compliance with medication dose and prothrombin time testing is essential to optimizing its impact. Poor compliance with anticoagulants has been documented in randomized trials1, 2and is a frequently cited concern of physicians.[11]Nonetheless, ours was the first study to explore patient features associated with noncompliance with anticoagulation.
In general, previous compliance studies have focused on rates of medication
Acknowledgements
We gratefully acknowledge the assistance of Mary A. Sheehan, RN, Robert A. Hughes, MD, and the staff of the Anticoagulation Therapy Unit at Massachusetts General Hospital.
The research reported in this paper was supported in part by a grant from the Eliot B. Shoolman Fund, Massachusetts General Hospital, Boston, Massachusetts. Dr. Arnsten was a fellow of the Harvard General Internal Medicine Fellowship Program, U.S. Department of Health and Human Services National Research Services Award Grant
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