title: Factors determining patients' intentions to use point-of-care testing medical devices for self-monitoring: the case of international normalized ratio self-testing.
abstract: OBJECTIVE
  To identify factors that determine patients' intentions to use point-of-care medical devices, ie, portable coagulometer devices for self-testing of the international normalized ratio (INR) required for ongoing monitoring of blood-coagulation intensity among patients on long-term oral anticoagulation therapy with vitamin K antagonists, eg, warfarin.
  
  
  METHODS
  A cross-sectional study that applied the technology-acceptance model through a self-completed questionnaire, which was administered to a convenience sample of 125 outpatients attending outpatient anticoagulation services at a district general hospital in London, UK. Data were analyzed using descriptive statistics, factor analyses, and structural equation modeling.
  
  
  RESULTS
  The participants were mainly male (64%) and aged ≥ 71 years (60%). All these patients were attending the hospital outpatient anticoagulation clinic for INR testing; only two patients were currently using INR self-testing, 84% of patients had no knowledge about INR self-testing using a portable coagulometer device, and 96% of patients were never offered the option of the INR self-testing. A significant structural equation model explaining 79% of the variance in patients' intentions to use INR self-testing was observed. The significant predictors that directly affected patients' intention to use INR self-testing were the perception of technology (β = 0.92, P < 0.001), trust in doctor (β = -0.24, P = 0.028), and affordability (β = 0.15, P = 0.016). In addition, the perception of technology was significantly affected by trust in doctor (β = 0.43, P = 0.002), age (β = -0.32, P < 0.001), and affordability (β = 0.23, P = 0.013); thereby, the intention to use INR self-testing was indirectly affected by trust in doctor (β = 0.40), age (β = -0.29), and affordability (β = 0.21) via the perception of technology.
  
  
  CONCLUSIONS
  Patients' intentions to use portable coagulometers for INR self-testing are affected by patients' perceptions about the INR testing device, the cost of device, trust in doctors/clinicians, and the age of the patient, which need to be considered prior to any intervention involving INR self-testing by patients. Manufacturers should focus on increasing the affordability of INR testing devices for patients' self-testing and on the potential role of medical practitioners in supporting use of these medical devices as patients move from hospital to home testing.
authors.affiliation: Multidisciplinary Assessment of Technology Centre for Healthcare, Brunel University London, Uxbridge, Middlesex, UK.
authors.forename: Syed Ghulam Sarwar
authors.initials: SG
authors.lastname: Shah
authors.forename: Julie
authors.initials: J
authors.lastname: Barnett
authors.forename: Jasna
authors.initials: J
authors.lastname: Kuljis
authors.forename: Kate
authors.initials: K
authors.lastname: Hone
authors.forename: Richard
authors.initials: R
authors.lastname: Kaczmarski
keywords: INR self-testing; affordability; home testing; oral anticoagulation; structural equation modeling; technology-acceptance model; trust in doctor