Development and psychometric evaluation of a sexual health care knowledge scale for oncology nurses

Objective: The purpose of this study was to develop a sexual health care knowledge scale for oncology nurses and to evaluate its psychometric properties using Rasch analysis and the known-groups technique. Background: Although sexual oncology has become a popular topic and sexual health care is now promoted, there has been a lack of instruments supported by psychometric evaluations to measure nurses' knowledge of sexual health issues. Methods: The initial 72 items were compiled to form the Sexual Health Care Scale - Knowledge (SHCS-K) for oncology nurses using a literature review and analysis of existing research tools. After a specialist panel verified content validity, the questionnaire was shortened to 58 items. The data were analyzed using a Rasch model to investigate the items with respect to unidimensionality of fit and difficulty and reliability distribution. Discriminant validity was examined using the known-groups technique. Results: Two items did not fit with the Rasch model. Person and item separation-index ratios were 3.33 and 9.45, respectively, which confirmed that the SHCS-K functioned well. The reliability was good, at 0.99. Significant differences in marital status, levels of education, and participation in SHC training were observed between groups. The final version of the questionnaire consisted of 55 items, with a total score range of 0-55. Conclusions: The SHCS-K was found to be a valid and reliable measure for evaluating levels of sexual health care knowledge among this sample of oncology nurses.