Design and psychometric properties of the quality of life questionnaire for veterans with combat related post-traumatic stress disorder

Combat-related post-traumatic stress disorder (combat-related PTSD) is a chronic and debilitating severe mental condition in people with experience of war events, which has a deeply negative impact on their quality of life. This study aimed to design and assess the psychometric properties of quality of life questionnaire (QOL-Q) for Iran-Iraq war veterans with combat-related PTSD. This study employed an explanatory sequential mixed methods design, which was conducted in Tehran duration 2016. In the qualitative phase, the quality of life concept was determined by using content analysis via a conventional approach. To gather data, semi-structured interviews were performed with individuals including 31 veterans with combat-related PTSD and 3 health monitoring physicians, as well as group discussions held with a group of 12 patients’ spouses. Based on the results obtained, questionnaire items were developed. In the quantitative phase, the psychometric properties of the questionnaire were conducted. The face and content validity was determined using both quantitative and qualitative methods. The construct validity was determined with the exploratory factor analysis and convergent validity using the 36-item quality of life questionnaire. The reliability was approved with the measurement of internal consistency using Cronbach's alpha coefficient and split-half, and the stability assessed using a test-retest method. Data analysis was performed with MAXQDA 10 software for qualitative data and SPSS 18 software for quantitative data. Explaining the concept of quality of life led to the formation of eight main categories and three themes under the headings “Disease outcomes”, “Health” and “Effective factors in compatibility”, and on the basis of this, an initial questionnaire with 73 items was developed. In the psychometric phase, after assessing the face and content validity, the number of items was reduced to 46. Construct validity through exploratory factor analysis led to the removal of 16 items and identification of 4 factors. Convergent validity with the 36-item QOL-Q with     r= 0.41was considered to be at an acceptable level (P<0.001). Reliability through a test-retest with r =0.93, and the split-half with r=0.776, confirmed Cronbach's alpha a=0.67. The final questionnaire with 30 items and four subscales including psychosocial, psychosomatic, self-esteem and religious attitude was presented. According to the questionnaire design, based on the concept of quality of life by veterans with post-traumatic stress caused by war experience, as well as suitable and acceptable validity and reliability, this questionnaire is qualified and empowered to use in different settings, for measuring quality of life in this group of patients, as well as their families. Results can be used to improve their treatment and care.