Evaluating the Longitudinal Item and Category Stability of the SF-36 Full and Summary Scales Using Rasch Analysis
Reinie Cordier; Ted Brown; Lindy Clemson; Julie Byles; Benjamin D. Wright
INTRODUCTION: The Medical Outcome Study Short Form 36 (SF-36) is widely used for measuring Health-Related Quality of Life (HRQoL) and has undergone rigorous psychometric evaluation using Classic Test Theory (CTT). However, Item Response Theory-based evaluation of the SF-36 has been limited with an overwhelming focus on individual scales and cross-sectional data. PURPOSE: This study aimed to examine the longitudinal item and category stability of the SF-36 using Rasch analysis. METHOD: Using data from the 1921-1926 cohort of the Australian Longitudinal Study on Women's Health, responses of the SF-36 from six waves of data collection were analysed. Rasch analysis using Winsteps version 3.92.0 was performed on all 36 items of the SF-36 and items that constitute the physical health and mental health scales. RESULTS: Rasch analysis revealed issues with the SF-36 not detected using classical m...
Reinie Cordier, Ted Brown, Lindy Clemson, Julie Byles, & Benjamin D. Wright (2018). Evaluating the Longitudinal Item and Category Stability of the SF-36 Full and Summary Scales Using Rasch Analysis. BioMed Research International, 2018, 1-30. https://doi.org/10.1155/2018/1013453