Confirmatory Validation and Measurement Equivalence of the Eating Loss of Control Scale in Binge Eating and Non-Clinical Samples

Although Loss of Control (LOC) is a transdiagnostic factor in eating pathology, there are few standalone assessments of LOC. The objective of this study was to evaluate the uni-dimensionality and measurement equivalence of the Eating Loss of Control Scale (ELOCS). Confirmatory factor analyses were used to achieve a well-fitting uni-dimensional model in clinical (N = 226) and non-clinical (N = 476) samples. Measurement equivalence was tested in a factor analytic framework, and effect sizes were computed to evaluate the impact of non-equivalence. A well-fitting model was achieved in both samples after the removal of 4 items. The instrument showed configural equivalence but not metric equivalence. Results suggest that the ELOCS is a reliable and valid measure of LOC in clinical and non-clinical samples. However, while the nature of the LOC construct is similar across binge eating and non-clinical participants, comparisons of ELOCS across these groups are affected by measurement non-equivalence. This research also revealed novel insights into the relative sensitivity of model fitting and effect size approaches to investigating measurement equivalence.