The aim of this study was to examine the trend in household catastrophic medical expenditure associated factors by continuous tracking of a household included for four years in annual surveys of 5,294 households. Apart from missing values in the final analysis, the study was based on raw data collected by the Korean Health Panel from 2008 to 2011.
Correspondence analysis was used to investigate the trend in the incidence rates of annual catastrophic medical expenditure and generalized estimating equation to examine the factors influencing the incidence of catastrophic medical expenditure.
A high incidence rate of household catastrophic medical expenditure in the year 2008 was determined for the following factors: elderly age of the householder, low education level of the householder, numerous elderly household members, low total annual household income, small per capita insurance number, low subjective health status of household members, and high prevalence of chronic disease in the household (p<0.05). Similar trends were seen for each year. A tendency toward an increase in incidence rates of catastrophic medical expenditure was noted between 2008 and 2011 for all factors, with slight decreases from 2008 to 2009 and from 2009 to 2010, followed by an increase in 2011.
The annual mean incidence rates of household catastrophic medical expenditure were 47.4%, 25.1%, 15.4%, 10.1%, 5.4% and 3.2% in the threshold levels of 5%, 10%, 15%, 20%, 30%, and 40% respectively. The incidence rate of household catastrophic medical expenditure at the 15% threshold point was seen in 15.3% of households in 2008. This number decreased by 1.9% in 2009 to 13.4% of households, but increased again to 15.7% in 2010 and to 17.0% in 2011. The four-year average incidence rate of catastrophic medical expenditure at the higher threshold point was lower in 2008 compared to 2011, and it increased at all threshold points in 2011.
The incidence rate of household catastrophic medical expenditure at the 15% threshold point was higher when the total annual household income was lower, the education level of the householder was lower, the healthcare coverage type was National Health Insurance compared to medical assistance, the householder had disability, the age of the householder was older, the number of household members was smaller, the subjective health status of household members was lower, and the prevalence rate of the chronic disease of the household was higher (p<0.05). Compared to 2008, the incidence rates were 1.154 times higher in 2011 and 1.037 times higher in 2010, but were 0.842 times lower in 2009 (p<0.05).
Therefore, a policy for vulnerable households with older or patient members of chronic diseases should be established.