Willingness to pay to prevent chemotherapy-induced nausea and vomiting.

Abstract

6068 Background: This study assessed willingness to pay (WTP) to avoid chemotherapy induced nausea and vomiting (CINV) among 303 cancer patients. Methods: WTP was assessed using results from a conjoint survey. Patients viewed 25 scenarios each involving 2 descriptions of CINV and indicated which they preferred. Each scenario represented a combination of levels from 8 CINV related attributes. Importance scores assessing attribute contribution to selection and WTP values were calculated using preference coefficients from a series of probit models. Results: Patients were 79% Caucasian and 16% African American. Mean age was 59.4 years (range=26-86). 40% had breast cancer, 35% lung cancer, and 25% colorectal cancer. 68% were on HEC/MEC, 22% had been on HEC/MEC in the last 6 months, and 10% were chemotherapy naïve. Important scores for attributes were cost: 0.21, chance nausea: 0.07, length nausea: 0.15, severity nausea: 0.16, chance vomiting: 0.02, frequency vomiting: 0.07, length vomiting: 0.18, and dehydration: 0.15, indicating cost was the strongest driver of patient choice and choice was driven more by a desire to avoid nausea than vomiting. Patients were willing to pay to avoid > 30% chance of nausea (WTP to avoid 50%: $42.61; WTP to avoid 70%: $49.57), > 1 day of nausea (2-5 days: $62.80; 5+ days: $107.50), vomiting > 1-2 times/day (3-5 times/day: $45.52; 5+ times/day: $52.10), and vomiting longer than a half-day (1 day: $20.12; 2-5 days: $133.05) with p-values from 0.0004 to <.0001. Patients with income $40,000+ were willing to pay more than others to avoid more than 1 day of nausea (2-5 days: difference=$93.23; 5+ days: difference=$107.43) and nausea that impaired self-care ($42.62) with p-values from 0.01 to <0.0001. Breast cancer patients were willing to pay less to avoid a 25% chance of vomiting versus lung (difference=$49.95; p=0.0083) and colorectal cancer patients (difference=$50.80; p=0.0166), respectively. WTP also varied by disease stage, ECOG performance status, HEC/MEC group, and whether patients had worked while on chemotherapy. Conclusions: The study identifies a significant WTP to avoid nausea and vomiting and substantial group differences in WTP that could be incorporated into the management of CINV.