An assessment of factorial structure and health-related quality of life in problem drug users using the Short Form 36 Health Survey

AIMS: To confirm the factorial structure of the Short Form 36 Health Survey (SF-36) in problem drug users and to compare their health-related quality of life (HRQOL) with general Dutch population norms.

METHOD: Data of 394 participants from the Amsterdam Cohort Study among drug users, who had completed once the SF-36 standard form (4 weeks recall) between February and August 2005, were analyzed. The factorial structure of the SF-36 was investigated by confirmatory factor analysis. Subsequently, sum scores of the eight SF-36 health dimensions were converted into z-scores by standardizing them with the mean and standard deviation of the corresponding general Dutch population age and gender group.

RESULTS: The factor structure was acceptable and also comparable with previous findings. Compared with the general population, participants had significantly lower z-scores on all of the eight SF-36 dimensions, with largest deviations in social functioning (M = -1.13) and mental health (M = -1.01), and smallest deviations in bodily pain (M = -0.32).

CONCLUSION: The results corroborate the factorial structure and reliability of the answers of problem drug users to the SF-36. Their HRQOL was low, even though it was assessed irrespective of substance abuse treatment settings.