International Normalized Ratio values in group versus individual appointments in a pharmacist-managed anticoagulation clinic

Abstract

The clinical effectiveness of a group-visit model versus individual point-of-care visits is compared by International Normalized Ratio (INR) monitoring in a pharmacist-managed anticoagulation clinic. This study was a prospective, randomized, repeated-measures, two-group, intention-to-treat comparison and survey at a pharmacist-managed anticoagulation clinic in a managed-care ambulatory care setting. Patients were eligible for this study if they were taking warfarin therapy for at least 30 days, had a goal INR range, and provided consent. At a routine point-of-care visit, eligible patients were randomly invited to participate in group visits. The number of visits and INR values were documented prospectively for both groups during the 16-week study period. Of the 45 patients who consented and enrolled in group visits, 28 patients participated for the 16-week study period. The control group included 108 patients seen by a pharmacist for individual anticoagulation appointments. No significant difference in the percentage of INR values within the therapeutic range was detected between patients in the group-visit model versus patients receiving individual visits (59% versus 56.6%, respectively; p = 0.536). Seventy-three percent of INR values for patients who attended group visits were within +/- 0.2 of the desired INR range compared with 71.9% of those in the control group ( p = 0.994). In addition, 79% of group-visit patients were within the therapeutic range at their last clinic visit compared with 67% of patients who attended individual appointments (p = 0.225). Group visits were preferred by 51% (n = 38) of patients who completed the satisfaction survey. Of the 92 patients who declined group-visit participation, 36% indicated that the time of day that group visits were offered was inconvenient. There were no thromboembolic or hemorrhagic events documented in either group during the study period. Group visits in a pharmacist-managed anticoagulation clinic may provide a safe and effective alternative to individual appointments.