Validity of the PARADISE24 questionnaire in people with substance use disorders: A measure to assess psychosocial difficulties.

OBJECTIVES: Psychosocial difficulties (PSDs) are common in people with substance use disorders (SUDs). The PARADISE24 has been shown to be an adequate tool for measuring PSDs in inpatients with SUDs. The aim of this study is to evaluate the psychometric properties of the PARADISE24 in a sample of patients with SUDs. METHODS: 2637 participants with SUDs completed the PARADISE24 questionnaire during their treatment. The latent structure of the PARADISE24 questionnaire was analyzed in the outpatient sample by means of exploratory and confirmatory factor analysis (EFA and CFA). Metric invariance was then assessed in relation to the inpatient sample using multiple group CFA. Finally, evidences of known-groups validity were checked to test the ability of the questionnaire to differentiate between socio-demographic and clinical groups. RESULTS: The one-factor model presented an adequate fit in both the EFA (CFI = 0.98; TLI = 0.98; RMSEA = 0.07) and the CFA (CFI = 0.98; TLI = 0.98; RMSEA = 0.07) solutions. The reliability of the scale was found to be high (α = 0.93). Strict metric invariance between inpatients and outpatients was achieved (RMSEA = 0.063; TLI = 0.983; CFI = 0.981). The PARADISE24 was able to discriminate between the inpatients and outpatients at both latent (d = 0.98) and observed levels (d = 0.86). CONCLUSIONS: The PARADISE24 is a unidimensional tool that is reliable for assessing and comparing PSDs in both outpatients and inpatients with SUDs. Further research is required for evaluating the ability of the PARADISE24 to quantify longitudinal changes in PSDs.