Patient Specific Factors Influencing Adherence to INR Monitoring

The specific reasons underlying nonadherence to monitoring the international normalized ratio (INR) from the patient's perspective have not been formally studied. Understanding why patients do or do not adhere has the potential to reveal useful targets for improving adherence to INR monitoring or alternative treatment strategies. The objective of this study was to gain further insight into INR monitoring nonadherence from the patient's perspective.

This qualitative study was conducted among members of Kaiser Permanente Colorado; patients were characterized as adherent or nonadherent and recruited from the Clinical Pharmacy Anticoagulation and Anemia Service to participate in an individual interview. Qualitative analysis was performed to identify emerging themes using an inductive approach. Demographic data were summarized using descriptive statistics.

Patients were primarily white and employed with a mean age of 61.3 years. Perspectives and experiences were similar for all interviewed patients regardless of classification as adherent or nonadherent. The most common themes were the desire for INR monitoring to be inexpensive, convenient, and accessible; finding reassurance with INR monitoring; and a preference for interacting with the same group of prescribers, pharmacists, and phlebotomists.

The following strategies to improve adherence to INR testing are suggested: (i) assign anticoagulation providers to work with the same patients consistently; (ii) provide formal INR reminders; (iii) avoid harsh language or lecturing patients following missed INR tests; (iv) reinforce the clinical and psychological utility of INR results; and (v) facilitate access to INR testing. Adopting these strategies into clinical practice can support the patient-clinician relationship and empower patients to be more engaged in their health care.