RELIABILITY AND VALIDITY OF AN HIV-SPECIFIC HEALTH-RELATED QUALITY-OF-LIFE MEASURE FOR USE WITH INJECTING DRUG-USERS

Objective: To assess the reliability and validity of an HIV-specific q uality of life (QoL) questionnaire for use with injecting drug users ( IDU). Method: One hundred IDU with HIV infection (27 asymptomatic, 48 symptomatic, 25 with AIDS) completed the HIV adaptation of the Medical Outcomes Study questionnaire (MOS-HIV). Validity of the scale was ass essed by comparing the scores on the MOS-HIV with measures of health a nd psychological status. Measures of health status used included Cente rs for Disease Control and Prevention (CDC) stage, CD4 cell count and number of HIV-related illnesses. Psychological status was assessed usi ng the Hospital Anxiety and Depression Scale. Sociodemographic data an d information on illegal drug consumption were also collected. Results : The MOS-HIV showed a good internal reliability on all scales and the factor structure was comparable with that reported from previous stud ies. The psychological scales from the MOS-HIV showed good concurrent validity. For the physical aspects of QoL, however, some scales were p oor at discriminating between different HIV disease stages. One reason for this may have been that factors associated with a history of inje cting drug use had a significant negative impact on QoL, particularly for asymptomatic patients. It was notable that QoL in asymptomatic inf ection was found to be substantially lower than has been reported for gay/bisexual men using the same instruments and was more strongly asso ciated with factors related to drug use rather than to HIV disease sta tus. Conclusion: The MOS-HIV is a reliable and valid measure, but in p atients with a history of injecting drug use some of the scales measur ing the physical aspects of QoL may be relatively insensitive to chang es in health.