Measurement Invariance of the Adolescent Quality of Life-Mental Health Scale (AQOL-MHS) across Gender, Age and Treatment Context

The Adolescent Quality of Life-Mental Health Scale (AQOL-MHS) was designed to measure quality of life in clinical samples of Latino adolescents aged 12–18 years, but has also been used in community samples. The original measure included three factors: Emotional Regulation (ER), Self-Concept (SC) and Social Context (SoC). The goals of this study are to replicate the factor structure using confirmatory factor analysis (CFA), shorten the instrument and test the degree of measurement invariance across gender, age, and type of sample. Participants for the analyses (N = 354) came from two populations in the San Juan Metropolitan Area: (1) adolescents from randomly selected households, using a multi-stage probability sampling design (n = 295), and (2) adolescents receiving treatment at mental health clinics (n = 59). We first carried out a conceptual item analysis for item reduction purposes and then assessed dimensional, configural, metric and scalar invariance for each factor using the Mplus software system. The original 3-factor structure was replicated with comparable model fit in each treatment context. Metric invariance was attained for all three scales across groups. Either full or partial scalar invariance was also observed with DIF in a total of 6 items. Invariance testing supports the use of the abridged 21 item version of the AQOL-MHS to compare diverse individuals with little bias using observed scores, but for refined estimates the ideal scoring will be from a latent variable model.