PCN70 COST-EFFECTIVENESS OF ADHERENCE AND PERSISTENCE INTERVENTIONS FOR ADJUVANT TAMOXIFEN THERAPY

Abstract

Adjuvant tamoxifen therapy reduces the risk of breast cancer recurrence and mortality. Poor adherence and persistence to therapy adversely impact patient outcomes. This study evaluates the cost-effectiveness of adherence and persistence interventions for patients on adjuvant tamoxifen therapy as compared to usual care from a payer’s perspective. A five-state Markov model was developed to evaluate four hypothetical interventions. The Restart-Stopped intervention targets women who have discontinued tamoxifen and increases the proportion that restart therapy. The Never-Stop intervention targets all women on therapy and decreases discontinuation. The High-to-High intervention focuses on maintaining the current adherence level among women with high adherence (proportion of days covered ≥80%). The Low-to-High intervention focuses only on women with low adherence, and increases the proportion who become highly adherent. Annual cycles and a five-year time horizon were used. Model inputs were obtained from the literature. Relative improvement in adherence or persistence was varied and the associated program cost was estimated for assessing incremental cost-effectiveness at a willingness-to-pay (WTP) threshold of $100,000/QALY. Cost and benefits across all interventions were compared at a 5% relative increase in adherence or decrease in discontinuation over the 5-year time horizon. The Restart-Stopped intervention was cost-effective at a per-patient per-year (PPPY) cost of $445 and saved 4 lives/1,000. The Never-Stop intervention was cost-effective at $177 PPPY and saved 5 lives/1,000. The High-to-High intervention was cost-effective at $290 PPPY and saved 6 lives/1,000. Lastly, the Low-to-High intervention was cost-effective at $545 PPY and saved 4 lives/1,000. At a 5% effectiveness level, persistence interventions focusing on decreasing discontinuation and adherence interventions targeting patients with high-adherence resulted in more lives saved and met the willingness to pay threshold at a lower cost. Interventions targeting persistence have the greatest potential to improve life expectancy with greater cost-effectiveness.