Sample characteristics
The predisposing, enabling, and need characteristics along with emergency care utilization are presented in Table 1. Overall, survey respondents were more likely to have just primary/middle schooling, to be married, and to be 65-79 and male (Table 1).
The average age of the respondents was 73.9 (±6.7) years old, with 87.69% of the respondents being female. 54.87% of the respondents were married. For educational attainment, 23.28% of the respondents had no schooling, 60.22% had primary/middle schooling, 12.22% had high schooling, and 4.28% received college education or higher. The annual family incomes ranged from 15.9 million won to 76.1 million won. More specifically, 79.12% of the respondents earned an annual family income of <20 million won, 9.04% earned 20-40 million won, 9.70% earned 40-70 million won, and 2.14% earned 70 million won or more. For area of residence, 65.13% of the respondents resided in non-capital areas while 34.87% resided in capital areas. In response to questions about self-perceived/reported and observed health, 47.21% of the respondents evaluated their health as poor or very poor, and 52.79% evaluated their health as fair, good, or very good. 76.50% of the respondents had no disability while 23.50% reported having a disability. 97.67% of the respondents had chronic diseases while 2.33% had no chronic disease.
Bivariate analysis
Those who were most likely to have used EMS were primarily those who were 65-79, were women, were unmarried/divorced/separated/widowed, had primary/middle schooling, rated their health as fair or good or very good, had no disability, had chronic diseases, lived in the non-capital area, and had a yearly family income of 0-20 million won (Table 2).
In the initial stage of the analyses, variables such as age, sex, education, marital status, income, residence, self‐perceived health status, chronic disease, and disability remained significant predictors of EMS utilization. All tests were conducted at the 5% level of significance.
Multivariate analysis
The odds ratios for EMS utilization, simultaneously adjusted for multiple independent variables, are presented in Table 3. After adjusting for an array of predisposing factors (stage 1), older adults who were most likely to have utilized EMS included those who were unmarried/divorced/separated/widowed and women. Among all the predisposing variables, two variables, sex and marital status (except for age and education), were significantly associated with whether EMS was utilized.
These relationships were reexamined, adjusting for need (stage 2). Those with fair, good, or excellent health status and those who had chronic diseases were more likely to have used EMS than their counterparts.
The need variables had little impact on the subgroup differences in EMS utilization (see Table 3). The differences between demographic subgroups (those ages 65-79 versus adults over 80+, men versus women, and those who had high schooling or more versus middle schooling or less) widened in Stage 2. The predisposing factor (marital status) that exhibited non-significant effects in stage 1 became significant in Stage 2. The predisposing factor (education) which became insignificant in Stage 1 remained insignificant in Stage 2. These findings suggest health status and chronic disease remain important predictors of EMS utilization.
The impact of the enabling factors income and residence was examined in stage 3. Those with an annual family income of more than 70 million won were four and a half times more likely to use EMS than those with an annual family income of less than 70 million won. Those who lived in non-capital areas were one and a half times more likely to use EMS than those who lived in the capital area. Adjusting for the resource variables such as place of residence and income had little impact on the odds ratios of EMS utilization for the predisposing and need factors. The predisposing factor (education) which was significant in Stage 2 became non-significant in Stage 3. The remaining subgroup differences remained about the same once the resource variables were taken into account.
In sum, income and residence did not account for the remaining subgroup differences in using EMS among older Koreans, as observed in stage 3. Nonetheless, they remain significant independent determinants of EMS utilization.
The chi-square-based test for assessing how well the models fit the data resulted in a significant result, i.e., p< 0.0001 (Table 3).