The quality of eight health status measures were compared for chronic opioid dependence.

OBJECTIVE

To provide a comparative analysis of the psychometric properties of eight measures of health status among chronic opioid-dependent patients.

STUDY DESIGN AND

SETTING

Longitudinal data were analyzed for 251 patients enrolled in the North American Opiate Medication Initiative randomized controlled trial, conducted in Vancouver, British Columbia and Montreal, Quebec, Canada. Content validity, evidence of floor and ceiling effects, internal consistency, construct validity, and responsiveness were assessed for the Addiction Severity Index (ASI) medical and psychiatric (ASImed and ASIpsych) composite scores, the Maudesley Addiction Profile (MAP) physical and mental health scores (MAP-physical health score [MAP-PHS], MAP-mental health score [MAP-MHS]), the World Health Organization Disability Assessment Schedule-II, the EuroQol Group's EQ-5D index score and visual analog scale, EuroQol visual analog scale (EQ-VAS), and the Short Form SF-6D index score.

RESULTS

ASImed was best able to discriminate among patients with and without chronic conditions. The MAP-PHS and MAP-MHS were not unidimensional. ASImed and ASIpsych had prominent ceiling effects. ASImed, MAP-MHS, MAP-PHS, EQ-VAS, and EQ-5D were all responsive to decreases in illicit drug use.

CONCLUSION

None of the instruments performed uniformly as "best" or "worst." The EQ-5D appeared to be the preferable generic, indirect utility measure. Our results provide an evidence base to inform selection and further development of health status measures in opioid-dependent populations.