Incremental cost evaluation study of INR self-monitoring versus laboratorial control or monitoring in health care centres, in Portugal.

Abstract

Oral anticoagulant therapy with vitamin K blockers has been increasing in the last few years and its effectiveness is directly related to maintaining INR values within the target range. The objective of this study is to evaluate the cost-effectiveness of INR auto-monitoring versus monitoring in a laboratory or a health care centre, in Portugal.The study was conducted from a social perspective and considered only the direct costs. A Markov model was developed that considered the evolution of a hypothetical patient cohort, in annual cycles, with a time horizon of 5 years. For each patient, prothrombin time monitoring was predicted in three different ways: auto-monitoring, laboratory monitoring, and monitoring in a health care centre. The parameters analyzed were life-years gained and QALYs.The auto-monitoring option had a cost-effectiveness per QALY of 542euro/QALY (4.71 QALYs and 4.74 life-years). Health centre monitoring showed a costeffectiveness of 526euro/QALY (4.66 QALYs and 4.70 life-years) and the laboratory option had a cost-effectiveness of 704euro/QALY (4.64 QALYs and 4.68 life-years).Results showed that auto-monitoring is the option that presents more benefits. Results for both auto-monitoring and monitoring in a health care centre are better than monitoring in a laboratory.