Quality of Life Assessment in Danish Heroin Assisted Treatment Patients: Validity of the SF-36 Survey

Quality of life assessment is a crucial component of evaluating the treatment of substance use disorders such as opioid addiction. This study assessed the structural and external validity of the short form (SF-36) Health Survey in patients enrolled in the Danish Heroin Assisted Treatment Program (HAT). Exploratory and confirmation factor analysis was performed on 541 patients enrolled in the supervised injected HAT program who completed the SF-36 questionnaire at enrollment and with planned follow-ups. To investigate external validity, we correlated SF-36 factors with hospital contact prior to enrollment in HAT. Exploratory and confirmatory factor analysis demonstrated acceptable levels of statistical fit for the standard eight-factor model and provided evidence that quality of life can reliably be measured over time in this sample. SF-36 factors were correlated with the amount of prior somatic hospital contact but not psychiatric hospital contact. A stepwise regression approach revealed that the general health factor and the physical functioning factor were preferentially employed to predict the amount of prior somatic hospital contact. Our findings support the validity of the SF-36 Health Survey as a measure of the quality of life in people undergoing Heroin Assisted Treatment. The fact that the factors structure of the SF-36 was stable over repeated measurements implies that it can be used as a measure of change in this population. Future studies should consider a longitudinal design and attempt to predict future hospital contact using quality-of-life measures in patients with opioid addiction.