Development of Warfarin Safety Monitoring System at Primary Health Care grounded on Chronic Care Model

Abstract

Warfarin, an anticoagulant with a high risk of fatal adverse effects, requires a safety monitoring system in primary health care. This study aimed to investigate the problems of warfarin use, discover factors related to blood clotting and develop a safety monitoring system for warfarin. A mixed method was conducted in two phases. Phase one consisted of home visits for 104 patients using warfarin and aimed to investigate the occurrence of warfarin problems and the percentage of patients who could control their International Normalised Ratio (INR). In phase two, focus groups including all stakeholders were conducted, which aimed to develop a community-based system grounded on the Chronic Care Model (CCM). The system was implemented for a month and evaluated using the qualitative data of the stakeholders' satisfaction. The results revealed that in phase one, 38.5% patients with warfarin at home had missed their treatment appointments. Their warfarin compliance was 91.1±21.3%. 53.5% of patients had unused warfarin at home; 37.4% had inappropriate warfarin storage; 13.1% suffered the side effect of minor bleeding; 17.3% had potential warfarin-herb interactions; and 61.3% experienced drug-warfarin interactions. Two factors significantly affecting the INR and %Time in Therapeutic Range (%TTR) were inappropriate warfarin dosages and taking other medications. %TTR was influenced by warfarin compliance. In phase two, the safety monitoring system and protocol were created using CCM. The developed system comprises six elements that were the joint effort of primary health care personnel and the inter-professional team of the hospital. This promoted the continuity of services from the hospital to the community. After one month of implementation by the health team, all three groups of stakeholders were satisfied with the results. We concluded that the main problems afflicting warfarin patients were missed treatment appointments, receiving extra medicines from other services, inappropriate dosages and non-compliance. The developed system covered patients in primary health care, and all stakeholders were satisfied with its outcomes.