Preference-weighted health status associated with substance use-disorders treatment

Cost-effectiveness analyses using preference-weighted health status as the measure of effectiveness allow for the direct comparison of cost-effectiveness ratios for physical and mental health interventions. However, these analyses are not commonly used for substance use-disorders interventions. We conducted a methodological evaluation of the relationship between preference-weighted health status and 6-month substance use-disorders treatment outcomes.

The design was an observational study of clients receiving substance use-disorders treatment. Fifteen high-volume treatment centers within a regional managed behavioral health care organization participated. There were 165 subjects (117 men, 48 women) diagnosed with current Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, substance dependence in the analysis. Baseline and 6-month data included substance-use quantity, frequency, and diagnostic criteria and preference-weighted Medical Outcomes Study Short Form-36 scores based on visual analog scale (VAS) and standard gamble (SG) conversion formulas.

Controlling for sociodemographic variables, VAS change for early remission at 6 months was 0.107 (p = .0002) (reference category continued dependence). SG change for early remission at 6 months was 0.041 (p < .0004). Using heavy drinkers as the reference category, VAS preference-weighted change was 0.062 (p = .10) for abstinent and 0.112 (p = .01) for moderate drinkers. SG preference-weighted change was 0.027 (p = .08) for abstinent and 0.046 (p = .01) for moderate drinkers.

These findings support the construct validity of preference-weighted health status in substance use-disorders treatment. Direct comparisons of the cost-effectiveness of substance use-disorders treatment with other mental or physical health interventions are critical during times of limited health care resources.