Determining the cost-effectiveness of a computer-based smoking cessation intervention in primary care

Purpose: To evaluate the incremental effectiveness and cost-effectiveness of a staged-based, computerized smoking cessation intervention relative to standard care in an urban managed care network of primary care physicians. Design: Decision-analytic model based on results of a randomized clinical trial. Methodology: Patient outcomes and cost estimates were derived from clinical trial data. Effectiveness was measured in terms of 7-day point-prevalence abstinence at 6 months post-intervention. Quality-adjusted life years (QALYs) and cost-effectiveness (CE) were calculated, with CE measured as cost per patient per life year saved and per quality-adjusted life years saved. CE estimates were adjusted to account for partial behavior change as measured in terms of progression in stage of readiness to quit. Sensitivity analyses were conducted to evaluate the robustness of key model assumptions. Principal findings: Intervention patients were 1.77 times more likely to be smoke-free at 6 months follow-up than those in standard care (p=.078). The intervention generated an additional 3.24 quitters per year. Annualized incremental costs were $5,570 per primary care practice, and $40.83 per smoker. The mean incremental cost-effectiveness ratio was $1,174 per life year saved ($869 per QALY). When the intervention impact on progression in stage of readiness to quit was also considered, the mean incremental cost-effectiveness ratio declined to $999 per life year saved ($739 per QALY). Conclusions: From a physician's practice perspective, the stage-based computer tailored intervention was cost-effective relative to standard care. Incorporation of partial behavior change into the model further enhanced favorability of the cost-effectiveness ratio.