A measure to assess adherence to prescribed home exercise: the Exercise Adherence Rating Scale (EARS)

Abstract

Background: Research shows that between 30 – 70% of people are non-adherent to prescribed exercise. However, there is no gold standard for measuring exercise adherence. Self-report diaries are commonly used, yet inaccurate recall and self-presentation bias may affect the validity of this data. The Exercise Adherence Rating Scale (EARS) is a valid and reliable measure that may provide better assessment of adherence, which may facilitate improved physiotherapy interventions to increase adherence. Methods: 150 patients with chronic low back pain (CLBP) were recruited from London-based hospitals (60% female; mean age 50 years, range 24 – 79 years). EARS items were developed based on literature searches, focus groups and interviews with CLBP patients, physiotherapists and psychologists. Exploratory factor analysis was used to assess the underlying factor structure of the EARS. Intraclass correlation coefficients and item response theory were used to assess reliability. Findings: A 1-factor solution explained 66% of the variance in adherence to exercise. Internal consistency (α = 0.758) and item-response theory methods (>0.7) indicated that reliability was acceptable, and test re-test reliability was high [ICC = 0.97 (0.94 – 0.98)]. The 6-item EARS is scored on a 5-point Likert scale (0-4, completely agree to completely disagree) where a higher score indicates better adherence. Discussion: This research may improve physiotherapy treatment by providing additional information about adherence that could be used to improve patient outcomes. Exercise can reduce pain and disability for people with CLBP. The EARS will allow better assessment of adherence to exercise which may facilitate increased adherence behaviour.