Cultural adaptation to Quechua and psychometric properties of the Family APGAR Scale in Peruvian adults in the San Martín Region

Objective: To adapt the Family APGAR (Adaptability, Partnership, Growth, Affection, Resolve) score to the Quechua language spoken in San Martín and evaluate its structural validity, reliability, convergent validity, and differential item functioning (DIF) among adults in the Peruvian Amazon. Methods: After forward and backward translation (Spanish-Quechua of San Martín-Spanish), the Family APGAR underwent cultural adaptation through expert review and a focus group from the target population. In a non-probabilistic sample of 402 Quechua-speaking adults from San Martín, Peru, confirmatory factor analysis was conducted to assess factorial structure. Reliability was estimated using Cronbach's alpha and McDonald's omega coefficients. Differential item functioning was examined using purified MIMIC (Multiple Indicators Multiple Causes) models. Results: The unidimensional model showed adequate fit (comparative fit index = 0.993; Tucker-Lewis index = 0.987; standardized root mean square residual = 0.044; root mean square error of approximation = 0.074), acceptable reliability (α = 0.78; ω = 0.79), and satisfactory convergent validity (average variance extracted = 0.52). Limited differential item functioning was identified: P4 showed differential item functioning by residence (β = 0.193; pBH < .001) and P3 by marital status (β = -0.117; pBH = .039), while no robust age-related differential item functioning was observed. Conclusions: The Quechua version of the Family APGAR showed a unidimensional structure with adequate validity and reliability. Overall psychometric performance was satisfactory, although the identified item-level differential item functioning should be considered when interpreting scores across sociodemographic groups.