Psychometric Properties of the Medical Outcomes Study Social Support Survey (MOS-SSS) in Peruvian adults diagnosed with chronic non-communicable diseases

Chronic non-communicable diseases (NCDs) impose a high health and social burden in Peru, significantly impacting patients' quality of life. In this context, perceived social support acts as a protective factor that contributes to stress adaptation, improves treatment adherence, and promotes healthy behaviors. The objective was to analyze the psychometric properties of the Medical Outcomes Study Social Support Survey (MOS-SSS) in a sample of Peruvian adults with NCDs. Specifically, the factor structure, reliability, and convergent validity of the MOS-SSS were evaluated. 200 Peruvian adults with NCDs (66% women, 34% men) participated. The MOS-SSS and the Quality-of-Life Index (QLI) were administered. Descriptive analyses, confirmatory factor analysis (CFA), reliability analyses (Cronbach's alpha and omega), and convergent validity analyses were performed. The MOS demonstrated adequate psychometric properties, with high reliability ( α and ω > .90 ), robust structural validity under a bifactor model with one general factor and four specific factors (CFI = .93, TLI = .91, SRMR = .04, RMSEA = .09 [90%IC: .07 y .10]), and evidence of essential unidimensionality (ECV = .87, ω_h = .95 ). Furthermore, a positive and significant association between perceived social support and quality of life was confirmed ( β = .58 ). It is concluded that the MOS-SSS Questionnaire is an instrument with evidence of validity and reliability for assessing perceived social support in Peruvian patients with NCDs, facilitating its use as a screening measure, as well as in health research and interventions to strengthen support networks and improve quality of life in this population.