Postpartum fatigue: assessing and improving the psychometric properties of the Fatigue Severity Scale

A brief, reliable, and valid measure of postpartum fatigue in both clinical and research settings is much needed. This study assessed the psychometric properties of the Fatigue Severity Scale (FSS) among women with unsettled infants and fatigue. Rasch analysis identified an overall ceiling effect for the original FSS, as well as disordered response categories and/or poor fit for 4 items. A modified 5-item version of the FSS (FSS-5R) had improved psychometric properties.