A Pilot Study to Evaluate Effectiveness of INR Self-Testing in Elderly Patients

OBJECTIVE: To determine if international normalized ratio (INR) patient self-testing (PST) resulted in an increased time in therapeutic range (TTR) in an elderly population when compared with clinic testing over a six-month period. DESIGN: A pilot study and retrospective chart review from August 2010 to August 2014. SETTING: Ambulatory, anticoagulation clinic with two locations in Sun City West and Peoria, Arizona. PARTICIPANTS: Of 91 patients, the data of 20 patients who were 65 years of age or older and had at least six months of pre- and post-PST INR data were extracted and analyzed. OUTCOMES: The primary outcome evaluated improvement of TTR during post-PST in elderly patients compared with clinic management over a six-month period. Secondary outcomes assessed patients' satisfaction with PST and identified barriers to PST. RESULTS: The post-PST mean TTR significantly increased to 73% from 63.6% for the first six months of PST (P = 0.04). Participants were satisfied with PST, with an average score ranging from 4.6 to 5 on a Likert scale of 1 to 5 on 10 satisfaction survey questions. Cost was identified as the most common barrier to PST, with 43% of patients not participating in PST because of financial burden. CONCLUSION: With appropriate screening and training, PST is associated with improved TTRs and higher patient satisfaction in elderly patients when compared with clinic testing. Barriers identified to PST include cost, the complex process, and noncompliance.