Abstract
BACKGROUND: While many multi-item measures are available to evaluate an individual's body image, study demands occasionally require the use of very brief measures, including single-items. However, little is known about how single-items perform relative to multi-item counterparts. METHODS: The present study aimed to evaluate the utility of two single-item assessments of appearance satisfaction, i.e. an individual's evaluation of their appearance, using a four-step and seven-step Likert scale and drawing on secondary data from three studies: (1) the Avon Longitudinal Study of Parents and Children (ALSPAC) (N = 5,952, aged 14), (2) a cross-sectional study of older adolescents primarily with probable eating disorder diagnoses (the STORY study) (N = 242, aged 16-25), (3) and a longitudinal study of emergent adults (the COVID study) (N = 201 participants aged 18-30). Thus, the present study aimed to examine the concurrent validity (Body Dissatisfaction Scale, children's mother-reported body dissatisfaction, Body Esteem Scale for Adolescents and Adults - Appearance Subscale), convergent validity (Eating Disorder Examination Questionnaire, Eating Disorder-15, the Patient Health Questionnaire version 4 and 8), and test-retest reliability of single items measuring appearance satisfaction. RESULTS: In study 1, the single-item measure showed good concurrent validity with the Body Dissatisfaction Scale for both boys and girls, and moderate concurrent validity with mother-reported body dissatisfaction for girls only. In study 2, acceptable - yet lower - convergent validity was established in a female population with probable eating disorders, and strong convergent and concurrent validity in a small healthy control population. In study 3, strong significant convergent and concurrent validity were established for the implemented single-item assessment in emerging adults with and without a self-reported eating disorder diagnosis, as well as acceptable test-retest reliability. CONCLUSION: These results provide insights into the utility of two highly similar single-item assessments of appearance satisfaction and give preliminary support for the use of similar measures in research (specifically for female non-eating disorder populations) when necessary.