Psychometric evaluation of the Persian version of the shared decision‑making questionnaire in patients undergoing emergency surgery

Accurate assessment of shared decision-making (SDM) is essential in emergency surgery, yet no culturally adapted and validated instrument is available in Iran. This study aimed to translate, culturally adapt, and assess the psychometric properties of the Persian SDM-Q-9 among patients undergoing emergency surgery. This methodological cross-sectional study followed a forward–backward translation procedure to adapt the SDM-Q-9 into Persian. Face and content validity were established prior to construct validation. Data were collected from 575 patients undergoing emergency surgery and randomly split into two independent subsamples for exploratory factor analysis (EFA; n = 287) and confirmatory factor analysis (CFA; n = 288). Internal consistency was assessed using Cronbach’s alpha, McDonald’s omega, and composite reliability (CR). Convergent validity was examined using average variance extracted (AVE). The data were suitable for factor analysis (Kaiser–Meyer–Olkin [KMO] = 0.923; Bartlett’s test of sphericity: χ² = 3433.445, df = 36, p < 0.001). EFA using Maximum Likelihood (ML) extraction with Promax rotation supported a single-factor structure explaining 58.60% of the total variance, with all factor loadings exceeding 0.70. CFA of the independent validation subsample initially showed inadequate fit for the one-factor model. After reviewing modification indices and item content, three theoretically justified residual correlations were retained. The resulting model showed good fit (χ²/df = 2.78, Comparative Fit Index [CFI] = 0.962, Tucker–Lewis Index [TLI] = 0.944, Root Mean Square Error of Approximation [RMSEA] = 0.059, and Standardized Root Mean Square Residual [SRMR] = 0.052). Factor loadings ranged from 0.67 to 0.84, supporting a predominantly unidimensional structure. The scale demonstrated strong internal consistency (Cronbach’s alpha = 0.921, McDonald’s omega = 0.926, and CR = 0.924). Convergent validity was supported by an AVE of 0.576. The Persian SDM-Q-9 demonstrated satisfactory validity and strong reliability for assessing patient-perceived shared decision-making in emergency surgical settings in Iran. Its predominantly unidimensional structure supports its use, although the localized residual associations identified in CFA warrant replication in independent, multicenter samples.