Exploring measurement invariance by gender in the profile of mood states depression subscale among cancer survivors
PurposeThe Profile of Mood States Short Form (POMS SF) is a well validated tool commonly used in medical/clinical research. Less attention has been paid to the measurement invariance of the POMS the degree to which the structure and items behave similarly for different groups (e.g. women and men) This study investigated the measurement invariance of the POMS Depression subscale across gender groups in a sample of cancer survivors.MethodsThe POMS Depression subscale has 8 items (Unhappy, Sad, Blue, Hopeless, Discouraged, Miserable, Helpless, and Worthless) Invariance was measured using multigroup confirmatory factor analysis. This study used data from American Cancer Society Studies of Cancer Survivors II, a population based survey of adult cancer survivors (n 9170).ResultsWe found factor structures and factor loadings were invariant for gender groups, but moderate differential item functioning (DIF) in the question containing the word blue.ConclusionWith regard to cancer survivors' gender, we found the Depression subscale of the POMS SF had configural invariance, and partial metric and scalar invariance. This suggests that results should be interpreted with caution, especially when gender is considered important. More broadly, our finding suggests that questions with the word blue may introduce DIF into other measures of depressive mood. More research is needed to replicate these findings in other samples and with other instruments.
Quality of Life Research