Value of Performing a Rasch Analysis on a Reliable and Valid Instrument—Case Study of the SA-SH

Abstract

Background and PurposeThe aim of this study was to explore the potential added value of performing a Rasch analysis on a reliable and valid instrument employed in nursing research and educational interventions, using the Students' Attitudes toward Sexual Health (SA-SH) as an example.MethodsThis study was performed with a polytomous Rasch model.ResultsThe Rasch analysis confirmed the reliability and validity of the SA-SH. Rasch analysis presented information about the item's individual response options and gave the opportunity to judge how well different answers alternated in an item. The Rasch analysis also provided information about the proportion of extremes and the possibility of excluding these.ConclusionsThe Rasch analysis provides added value regarding information that needs to be considered regarding choices of questionnaire literacy compared to item fit. The SA-SH is also valid and reliable when tested with Rasch analysis.