Development and psychometric testing of the Research Competency Scale for Nursing Students: An instrument design study

Background: Undergraduate students make up the largest pool for the recruitment of future nurses. The fundament for developing research competency has to be laid at this level of education. Objectives: To evaluate the construct validity, reliability, sensitivity to change and convergent validity of the Research Competency Scale for Nursing Students (RCS-N). Design: A psychometric study with repeated measurements. Setting: Nursing school from Sichuan, China. Participants: 146 undergraduate nursing students. Methods: Construct validity was evaluated with exploratory factor analysis, confirmatory factor analysis (CFA) and item response theory (IRT) analysis. Internal consistency reliability was determined with Cronbach's alpha, and IRT based reliability estimates were also provided. Sensitivity to change was evaluated with repeated measures ANOVA. Convergent validity was analyzed based on the correlation of the RCS-N scores with nursing research class examination scores. Results: Exploratory factor analysis yielded one dominant factor explaining 72.59% of the items' variance. CFA confirmed unidimensionality of the scale and produced appropriate goodness of fit indices after accounting for local dependency by collapsing several items to testlets. IRT analysis demonstrated a good capability of the scale to differentiate between persons with different abilities. Internal consistency was excellent (alpha = 0.98) and IRT based reliability was good to excellent. The participants' RCS-N scores increased significantly from 29.3 before participation in the research methodology class to 62.6 after the class. There was no correlation (r = 0.16, p = 0.051) between the RCS-N result and class test scores. Conclusions: RCS-N is a promising, valid and reliable tool for evaluating the research competency of undergraduate nursing students. The scale can however not replace actual examination of students' knowledge acquired in research methodology courses.