Assessing the reliability of household expenditure data: results of the World Health Survey.
The World Health Survey (WHS) which has been implemented in more than 70 countries with standardized questionnaires opens a great opportunity for research on health care financing issues. This study examines the household expenditures and health expenditure collected in the WHS in terms of reliability, consistency between different ways of data collection within the survey and with other types of household surveys. Data used in this study include 50 WHS and 37 other type of surveys, namely the Living Standard Measurement Survey, Household Budget Survey and Income and Expenditure Survey. The analysis consists of comparison of test-retest results; the aggregated and reported total household expenditure and health expenditure; the expenditures from the WHS and other type of surveys. The results from test-retest are fairly similar in the WHS. For health expenditure the average of reported total is lower than the aggregated total while for household total expenditure the estimate is similar from the two measures. Finally the WHS was found to report lower total household expenditure but higher out-of-pocket expenditure comparing with other types of surveys. The study suggests further efforts to standardize the questions in collecting expenditure data in household surveys for the purpose of cross-country and over time comparison.