Economic evaluation of a randomized controlled trial of pharmacist-supervized patient self-testing of warfarin therapy

OBJECTIVES: The increase in numbers of patients requiring oral anti‐coagulation testing in outpatient clinics has focused attention on alternative flexible systems of anti‐coagulation management. One option is pharmacist led patient self‐testing (PST) of international normalised ratio (INR) levels. PST has demonstrated improvements in anti‐coagulation control, but its cost‐effectiveness is inconclusive. This study reports the first cost‐effectiveness evaluation of a randomized controlled trial of an automated direct‐to‐patient expert system, enabling remote and effective management of patients on oral anti‐coagulation therapy. METHODS: We conducted an economic evaluation alongside a randomised controlled trial investigating a pharmacist led PST method. The primary outcome was to determine the cost effectiveness of PST in comparison with usual care (management in a hospital based anti‐coagulation clinic). Long term anti‐coagulation patients were recruited to a 6 month cross over study between PST and routine care in an anti‐coagulation clinic. Economic evaluation was from the healthcare payer perspective. RESULTS: On a per patient basis over a 6 month period, PST resulted in an incremental cost of € 59.08 in comparison with routine care. Patients achieved a significantly higher time in therapeutic range (TTR) during the PST arm in comparison with routine care, (72 ± 19.7% vs. 59 ± 13.5%). Overall cost of managing a patient through pharmacist supervised PST for a 6 month period is € 226.45. Additional analysis of strategies from a societal perspective indicated that PST was the dominant strategy. CONCLUSIONS: Pharmacist led patient self‐testing is a viable method of management. It provides significant increases in anti‐coagulation control for a minimal increase in cost.