Validation of the Evidence-based Practice Confidence (EPIC) Scale among Occupational Therapists

Background. Self-efficacy is a key theoretical construct that should be considered when aiming to improve the implementation of evidence-based practice (EBP) among occupational therapists (OTs). Current available tools measuring self-efficacy to implement the steps of EBP in the field of occupational therapy contain a limited number of EBP steps without strong evidence of reliability or validity. Thus, there exists a need for a reliable and valid tool to evaluate EBP selfefficacy among OTs. Objectives. To evaluate the reliability (test-retest, measurement error, minimum detectible change (MDC), and internal consistency), floor and ceiling effects and known groups construct validity of the evidence-based practice confidence (EPIC) scale among OTs. To evaluate construct validity, we tested hypotheses that level of education, education in EBP, EBP knowledge and skill, participation in EBP activities, and participation in research would be positively associated with self-efficacy rated on the EPIC scale. Method. A repeated measures study involving a baseline and a follow-up mail survey was conducted. A random sample of 1077 registered OTs in Ontario, Canada was mailed the EPIC scale and a questionnaire to evaluate construct validity. A second copy of the EPIC scale was mailed on receipt of a completed baseline questionnaire to evaluate test-retest reliability. Results. One hundred and twenty-six OTs completed the EPIC scale and construct validity questionnaire at baseline and 79 completed the EPIC scale at retest. Test-retest reliability (intraclass correlation coefficient (ICC)) was 0.92 (95% confidence interval (CI), 0.88-0.95, n=79). The MDC95 was calculated to be 4.6 %points. Internal consistency, estimated using Cronbach’s α, was 0.91 (95% CI 0.89-0.93, n=126). None of the participants obtained a total score of 0 or 100 %points on the EPIC scale. Participants with a master’s degree had higher ratings on the EPIC scale than those with a bachelor degree or diploma (U=1225, p<0.001). Therapists who reported previous academic training in EBP had higher ratings than those with no EBP training (mean difference=8.3 %points, 95% CI 2.2 to 13.9). Participants with high levels of EBP self-efficacy more frequently conducted online literature searches (U=1319, p=0.04), read or reviewed literature related to their clinical practice (mean difference=8.5 %points, 95% CI 1.8 to 15.3), and used professional literature and research findings in clinical decision-making (mean