Reliability and validity of the Kurdish version of the patient health questionnaire-15 in a trauma-affected population

BACKGROUND: Somatic symptoms are common among trauma-exposed populations and are often associated with persistent distress and functional impairment, highlighting the need for culturally appropriate assessment tools. OBJECTIVE: This study aimed to translate and culturally adapt the Patient Health Questionnaire-15 (PHQ-15), a screening measure of somatic symptom burden, into Central Kurdish and assess its psychometric properties among survivors of chemical gas exposure. METHODS: A total of 534 survivors were recruited through community and registry sources. After translation and cultural adaptation, item 4 and item 11 were removed due to cultural and gender-specific considerations and limited psychometric performance, resulting in a 13-item version. Factor structure was examined using confirmatory factor analysis (CFA) and exploratory structural equation modeling (ESEM). Measurement invariance across gender and age groups was evaluated using multi-group CFA. Internal consistency was assessed using McDonald’s omega. An exploratory network analysis (EBICglasso) examined conditional associations among symptoms. RESULTS: Both a unidimensional CFA model (CFI = 0.988, RMSEA = 0.054) and a three-factor ESEM model (CFI = 0.992, RMSEA = 0.046) showed good model fit, with the ESEM structure providing a more differentiated representation of pain/fatigue, gastrointestinal, and cardiopulmonary domains. Measurement invariance testing supported full scalar invariance across gender, while partial metric invariance was observed across age groups. Internal consistency was acceptable (ω = 0.70–0.83). Network estimates demonstrated acceptable stability, with correlation stability coefficients of 0.59 for edge strength and 0.52 for bridge strength, and should be interpreted as exploratory. CONCLUSION: The culturally adapted 13-item Kurdish PHQ demonstrates acceptable reliability and initial evidence of construct validity in trauma-exposed survivors of chemical attacks. The instrument may be used as a screening tool for somatic symptom burden in this context, while further validation in broader Kurdish populations is recommended.