Difference of Responses Among Face to Face, Telephone, and Online Survey: A Pilot Study in Measuring Willingness to Pay Per Qaly of Three Health Conditions

Abstract

This study examines responses to Willingness to pay (WTP) questions across face to face, telephone, and online modes of administration. The three modes of survey data sets used in this study and delivered to different sample group for a total of 90 respondents conveniently. Dichotomous bidding followed by open-ended questions was employed to examine respondents' WTP for three scenarios. Descriptive statistics were applied to explain demographic and characteristics as well as the WTP values. The Chi-Square test and Kruskal-Wallis test were used to evaluate the differences responses between modes of administration. Demographic variables including sex, age, household income, expense, number of dependents showed no significantly different between the samples. Across all three modes, participants' response rate was higher, higher interpretation rate, and more costs of survey in face to face sample, but no statistically different. There was no difference in WTP maximum of life saving scenario among three modes of administration. Online elicitation can be more successful in generating valid responses than paper-based surveys, especially for sensitive issues. It may be possible to extend our findings to other valuation methods, and further work should consider the stability of choice preference elicitation techniques across different administration modes.