Objectives: We assess the cost-effectiveness of smoking relapse prevention interventions designed to keep quitters from resuming the use of cigarettes. Because relapse prevention is complementary to smoking cessation efforts, the appropriate test of its cost-effectiveness is whether it reduces the incremental cost-effectiveness ratio (ICER) of smoking cessation. The major goal of the study is to carry out such a test.

Methods: Data from a randomized trial that ascertained the effectiveness of alternative modes of smoking relapse prevention are combined with ICER estimates of smoking cessation to assess whether relapse prevention is cost-effective.

Results: The trial produced convincing evidence that relapse prevention yields statistically significant reductions in the proportion of quitters who are smoking at 24 months postquit. The intervention effects are substantial enough to raise the denominator terms of the smoking cessation ICER and, thereby, offset the amount relapse prevention adds to cost numerator terms. In this sense, smoking relapse prevention tends to pay for itself.

Conclusions: Smoking relapse prevention is a highly cost-effective addition to current efforts to curb cigarette consumption. Complementary health interventions of this sort should be assessed by different methods than those commonly found in the cost-effectiveness literature.