Patients' satisfaction associated with portable coagulometers for warfarin monitoring: a cross-sectional study

The use of point-of-care (POC) coagulometers for monitoring patients on vitamin K antagonist (VKA) treatment makes international normalised ratio (INR) results immediately available. The aim of this study was to compare patients' satisfaction with VKA treatment in two settings characterised by distinct ways of monitoring: POC INR versus laboratory INR.

We recruited adult patients on long-term warfarin treatment (July 2017-February 2018) from the Anticoagulation Clinics at five district health centres (namely Cospicua, Floriana, Mosta, Qormi, Rabat-POC INR) and at Mater Dei Hospital (Msida - Laboratory INR) in Malta. We administered two psychometric questionnaires: the Duke Anticoagulation Satisfaction Scale (DASS) (range 25-175, lower scores corresponding to higher satisfaction) and the Perception of Anticoagulation Treatment Questionnaire (PACT-Q2) (range 0-100, higher scores corresponding to higher satisfaction).

We analysed 313 questionnaires (POC INR n=159, laboratory INR n=154). In the POC INR cohort, median age was 72 years and 59.1% were males; in the laboratory INR cohort, median age was 70.5 years and 46.1% were males. The POC INR cohort obtained significantly lower overall DASS score (p<0.001) and significantly higher PACT-Q2 scores (p<0.001 for the subscale "convenience"; p=0.039 for the subscale "anticoagulant treatment satisfaction") than the laboratory INR cohort. In multiple regression analysis, the use of POC coagulometers was significantly associated with the overall DASS score (p=0.013) and the PACT-Q2 convenience score (p=0.012).

Patients on warfarin treatment were generally satisfied. Patients monitored with the POC INR with a dedicated time slot reported less inconvenience and burdens and better psychological impact than patients monitored with the traditional laboratory INR.