Psychometric properties of the Peruvian version of the Nordic Musculoskeletal Questionnaire (NMQ)

Abstract Background Musculoskeletal problems are frequent in the adult population. The Nordic Musculoskeletal Questionnaire (NMQ) assesses the presence of musculoskeletal symptoms across nine body regions, and its total score represents an index of symptom burden across regions; however, psychometric evidence for its use in Peru is lacking. Objective To translate the NMQ into Peruvian Spanish and evaluate its structural validity, internal consistency, measurement invariance, and validity based on relationships with external variables in a sample of Peruvian adults. Methods A psychometric study was conducted with 1,215 participants. The mean age was 22.7 years (SD = 8.3), and 73.0% were women. The NMQ was translated and back-translated into Peruvian Spanish. Structural validity was evaluated through confirmatory factor analysis using the WLSMV estimator. Internal consistency was estimated using McDonald’s omega and Cronbach’s alpha. Measurement invariance according to sex and age was examined using multigroup CFA and MIMIC models, respectively. Validity based on relationships with external variables was evaluated through correlations with sleep problems, anxiety symptoms, and depressive symptoms. Results The one-factor scoring model showed sufficient structural validity: χ²(27) = 210, CFI = 0.957, TLI = 0.942, SRMR = 0.067, and RMSEA = 0.075 (95% CI: 0.065–0.084). Standardized factor loadings ranged from 0.67 to 0.77. Internal consistency was sufficient (ω = 0.794; α = 0.799). The NMQ symptom-burden index showed moderate positive correlations with sleep problems (ρ = 0.465), anxiety symptoms (ρ = 0.458), and depressive symptoms (ρ = 0.402), all p < .001. Measurement invariance according to sex and age was supported. Conclusion The Peruvian version of the NMQ showed psychometric evidence for its one-factor model, supporting its use for accurately assessing musculoskeletal symptoms in Peruvian adults.