Validation of scales measuring self-efficacy and outcome expectancy in evidence-based practice.

BACKGROUND: Evidence-based practice (EBP) is embraced internationally as an ideal approach to improve patient outcomes and provide cost-effective care. However, despite the support for and apparent benefits of EBP, it has been shown to be complex and difficult to incorporate in the clinical setting. Research exploring implementation of EBP has highlighted many internal and external barriers including clinicians' lack of knowledge and confidence to integrate EBP into their day-to-day work. Nurses in particular often feel ill-equipped with little confidence to find, appraise and implement evidence. AIMS: This study aimed to undertake preliminary testing of the psychometric properties of tools that measure nurses' self-efficacy and outcome expectancy in regard to EBP.
METHODS: A survey design was used in which nurses who had either completed an EBP unit or were randomly selected from a major tertiary referral hospital in Brisbane, Australia, were sent two newly developed tools: (1) Self-Efficacy in EBP (SE-EBP) scale and (2) Outcome Expectancy for EBP (OE-EBP) scale.
RESULTS: Principal Axis Factoring found three factors with eigenvalues above 1 for the SE-EBP explaining 73% of the variance and one factor for the OE-EBP scale explaining 82% of the variance. Cronbach's alpha for SE-EBP, three SE-EBP factors and OE-EBP were all >0.91 suggesting some item redundancy. The SE-EBP was able to distinguish between those with no prior exposure to EBP and those who completed an introductory EBP unit.
CONCLUSIONS: While further investigation of the validity of these tools is needed, preliminary testing indicates that the SE-EBP and OE-EBP scales are valid and reliable instruments for measuring health professionals' confidence in the process and the outcomes of basing their practice on evidence.