Association of willingness to pay with severity of chronic obstructive pulmonary disease, health status and other preference measures

SETTING: Willingness to pay (WTP) is a method frequently used to measure the benefits of health interventions in monetary terms. OBJECTIVE: To assess the construct validity of the WTP method in patients with chronic obstructive pulmonary disease (COPD). DESIGN: Fifty-nine COPD patients (34 men, mean age 57 years) were asked about their maximum WTP for a theoretical cure for COPD. In addition, they reported utility scores using standard gamble, time trade-off, a multi-attribute utility instrument, and a rating scale. They also responded to the Short Form 36 (SF-36) questionnaire, dyspnea measures and had comprehensive pulmonary function tests. RESULTS: The participants reported a median WTP of Norwegian kroner 200 000 (US $24 096) for a theoretical cure for COPD without side-effects. The associations of WTP with utility scores, dimensions of health status, dyspnea measures and lung function tests were low. CONCLUSION: The findings of this study question the validity of the WTP method in patients with chronic obstructive pulmonary disease.