Abstract
This study assessed preferences and willingness to pay for a new ICS/LAMA/LABA combination
inhaler among patients with chronic obstructive pulmonary disease (COPD), and for breast
cancer screening using mammography, using a discrete choice experiment (DCE) administered
through face-to-face interviews. To assess preferences and willingness to pay for a new
ICS/LAMA/LABA combination inhaler, the study included COPD patients aged ≥40 years who
had used inhaled medications for at least three months and were covered by the Universal
Health Coverage or Social Security schemes. Preferences and willingness to pay for breast
cancer screening using mammography were examined among women aged 40–70 years with
no history of breast cancer or severe breast disease, who were covered by the Universal Health
Coverage, Social Security, or Civil Servant Medical Benefit schemes. Data were collected across
four regions of Thailand, and DCE responses were analyzed within a random utility framework
using a mixed logit model. The DCE questionnaire for COPD patients included five attributes:
probability of inhaler use errors, number of inhalers, dosing frequency, inhalation effort, and
out-of-pocket cost. A total of 543 patients with COPD completed the DCE questionnaire. Outof-pocket medication cost was the most influential attribute affecting preferences. The highest
willingness to pay was observed for reducing the number of inhalers from three to one (964.33
THB/month). Direct questioning showed that 83.5% of respondents were willing to pay out of
pocket, with 71.0% willing to pay no more than 200 THB per month. Willingness to pay
declined to 54.0%, 23.2%, and 6.2% as monthly costs increased to 400, 800, and 1,600 THB,
respectively. The DCE questionnaire for mammography screening comprised four attributes:
waiting time for an appointment, travel time, service hours, and screening fee. A total of 558
respondents completed the DCE questionnaire. The mammography fee was the most
influential attribute affecting preferences. The highest willingness to pay was for expanded
service hours (1006.29 THB). Direct elicitation showed that 84.6% of respondents were willing
to pay up to 500 THB; willingness declined to 79.5%, 56.0%, and 24.6% at payment thresholds
of 1,000, 2,000, and 3,000 THB, respectively. Additionally, 13.2% reported being unwilling to
pay for or undergo mammography screening. In conclusion, cost was the dominant attribute
driving patient preferences.
