Cross-cultural adaptation, internal consistency, test-retest reliability and feasibility of the German version of the evidence-based practice inventory

BACKGROUND: A psychometrically robust measurement instrument is prerequisite to tailor and monitor interventions aiming to improve evidence-based practice (EBP). The recently developed “Evidence-based Practice Inventory” (EBPI) questionnaire (five dimensions) provides a sound inventory for a comprehensive assessment of adherence to EBP, and identification of barriers and facilitators for EBP. The aims of this study were to establish a German language version of the EBPI and to examine the instrument’s reliability in a diverse sample of healthcare professionals. METHODS: The English version of the EBPI was translated, adopted and subsequently test-retest reliability of the German language EBPI was examined in a nationwide online survey. Participants working in Germany were invited to complete the questionnaire twice. For each EBPI dimension, internal consistency reliability (Cronbach’s alpha) and the relative test-retest reliability (intraclass correlation coefficient, ICC) were calculated. The standard error of measurement, limits of agreement and minimal detectable change values were estimated to quantify measurement error. RESULTS: A German language version of the EBPI was established. In the online survey, the EBPI was initially completed by 889 healthcare professionals. At follow-up, 344 individuals (39%) completed the questionnaire (74% female; mean work experience: 13.6 years). The ICCs for the five dimensions varied between 0.78 and 0.86. The standard error of measurement varied between 6.5 and 8.8% of the respective dimension scale range, and the limits of agreement between 24 and 37%. For internal consistency reliability, alpha varied between 0.64 and 0.90. There were neither floor nor ceiling effects, nor any other relevant feasibility issues. CONCLUSIONS: The German language EBPI can be used to assess EBP adherence of healthcare professionals in clinical practice, and to identify barriers and facilitators for an EBP conform behaviour. Results on test-retest reliability indicate that the EBPI produces reliable scores when used for group comparisons, but the questionnaire seems insufficiently reliable for individual measurements over time. Methods of item response theory or Rasch measurement theory should be used for further evaluation and revision of the EBPI, informed by the results of this study. TRIAL REGISTRATION: German Clinical Trials Register (DRKS00013792). Registered 19 January 2018. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12913-019-4273-0) contains supplementary material, which is available to authorized users.