OBJECTIVES:

Achievement and maintenance of stable International Normalized Ratio (INR) in patients using vitamin k antagonists (VKA) remains a challenging task despite 60 years of clinical experience. We therefore aimed to develop a tool to assess Perceptions, Perspectives, Practice and Satisfaction in Patients Taking VKAs.

METHODS:

Following a thorough review of the literature, a thirty-two-item tool with four domains was created. A single-centre, prospective, observational pilot study was conducted among patients enrolled in an Anticoagulation Clinic (ACC) and receiving VKAs. The homogeneity of questions was calculated by the Cronbach’s alpha (α>0.70) coefficient, intraclass correlation coefficient (ICC>0.80) for reproductivity using IBM SPSS version 25.0.

RESULTS:

Two physicians, two academic professionals, and six practicing pharmacists validated the tool. The tool was tested on 30 patients taking VKAs. Internal consistency of each object in each domain was tested in order to test overall reliability. The homogeneity of questions was calculated by the Cronbach’s alpha (α) coefficient for Perceptions, Perspectives, Practice, and Satisfaction domains (0.83, 0.92, 0.79 and 0.88, p<0.001) respectively. The repetitiveness of the responses was also tested with the administration of a questionnaire on day 1 (test arm) and day 20 to patients (re-test arm: wash off for 14 days) and analyzed using intraclass correlation coefficient for each domain (ICC= 0.92, 0.96, 0.91, and 0.92, p>0.001) respectively. The item level content validity index (I-CVI) and scale level content validity index (S-CVI) was found to be 91%.

CONCLUSIONS: A tool for assessing Perceptions, Perspectives, Practice, and Satisfaction in VKA Patients has been developed and validated, and it has been found to be more reliable, reproducible, and has virtuous internal consistency.