Cost-effectiveness of a motivational intervention for alcohol-involved youth in a hospital emergency department

Abstract

Objective: Brief interventions in the emergency department targeting risk-taking youth show promise to reduce alcohol-related injury. This study models the cost-effectiveness of a motivational interviewing-based intervention relative to brief advice to stop alcohol-related risk behaviors (standard care). Average cost-effectiveness ratios were compared between conditions. In addition, a cost-utility analysis examined the incremental cost of motivational interviewing per quality-adjusted life year gained.

Method: Microcosting methods were used to estimate marginal costs of motivational interviewing and standard care as well as two methods of patient screening: standard emergency-department staff questioning and proactive outreach by counseling staff. Average cost-effectiveness ratios were computed for drinking and driving, injuries, vehicular citations, and negative social consequences. Using estimates of the marginal effect of motivational interviewing in reducing drinking and driving, estimates of traffic fatality risk from drinking-and-driving youth, and national life tables, the societal costs per quality-adjusted life year saved by motivational interviewing relative to standard care were also estimated. Alcohol-attributable traffic fatality risks were estimated using national databases.

Results: Intervention costs per participant were $81 for standard care, $170 for motivational interviewing with standard screening, and $173 for motivational interviewing with proactive screening. The cost-effectiveness ratios for motivational interviewing were more favorable than standard care across all study outcomes and better for men than women. The societal cost per quality-adjusted life year of motivational interviewing was $8,795. Sensitivity analyses indicated that results were robust in terms of variability in parameter estimates.

Conclusions: This brief intervention represents a good societal investment compared with other commonly adopted medical interventions.

Figure 1

Process flow chart and time estimates for two screening strategies for alcohol-involved youth in the emergency department (ED). The left-hand side of the flow diagram depicts identification and assessment of alcohol status conducted by hospital staff during routine ED intake (standard screening). The right-hand side of the flow diagram depicts added procedures to proactively scan the ED for youth and solicit information about alcohol involvement (enhanced screening). T = time; sec. = seconds; min. = minute; ETOH+ = alcohol implicated in risk behaviors; DC = discharge.

Figure 2

Motivational interviewing (MI) cost-effectiveness acceptability curve: Probabilistic sensitivity analysis results demonstrating proportion of times the cost per quality-adjusted life year ($/QALY) for MI fell below different thresholds of willingness to pay in a 10,000-simulation Monte Carlo analysis.