Table 3.
Incidence risk ratio (IRR) and 95 % confidence interval (CI) of inpatient care utilization with four types of status of public and private health insurance in the Korea Health Panel Survey, 2008–2011
| Model I | Model II | Model III | Model IV | |||||
|---|---|---|---|---|---|---|---|---|
| IRR | 95 % CI | IRR | 95 % CI | IRR | 95 % CI | IRR | 95 % CI | |
| Gender (Ref.: Men) | 1 | 1 | 1 | 1 | ||||
| Women | 1.08* | 1.01–1.16 | 1.05 | 0.97–1.12 | 1.07* | 1.00–1.15 | 1.07* | 1.00–1.15 |
| Age (Ref.: 20–29) | 1 | 1 | 1 | 1 | ||||
| 30–39 | 0.81** | 0.70–0.95 | 0.78** | 0.67–0.91 | 0.76** | 0.65–0.89 | 0.76** | 0.65–0.89 |
| 40–49 | 0.67** | 0.57–0.79 | 0.60** | 0.51–0.71 | 0.58** | 0.49–0.68 | 0.58** | 0.49–0.68 |
| 50–59 | 0.85 | 0.72–1.01 | 0.73** | 0.61–0.88 | 0.73** | 0.61–0.87 | 0.73** | 0.61–0.87 |
| 60 or older | 1.31*** | 1.11–1.55 | 1.05 | 0.87–1.26 | 1.05 | 0.87–1.26 | 1.05 | 0.87–1.26 |
| Chronic disease (Ref.: No) | 1 | 1 | 1 | 1 | ||||
| Yes | 2.31*** | 2.14–2.49 | 2.27*** | 2.11–2.45 | 2.18*** | 2.03–2.36 | 2.19*** | 2.03–2.36 |
| Marital status (Ref.: Single) | 1 | 1 | 1 | 1 | ||||
| Married couple | 1.99*** | 1.72–2.31 | 1.98*** | 1.71–2.89 | 2.08*** | 1.80–2.41 | 2.08*** | 1.80–2.41 |
| Divorced or Separated | 2.55*** | 2.05–3.17 | 2.40*** | 1.93–2.98 | 2.25*** | 1.81–2.80 | 2.25*** | 1.81–2.80 |
| Separation by death | 2.00*** | 1.66–2.41 | 1.91*** | 1.58–2.30 | 1.91*** | 1.59–2.31 | 1.91*** | 1.58–2.30 |
| Education (Ref.: College Degree or higher) | 1 | 1 | 1 | |||||
| High School to associate | 1.23*** | 1.12–1.35 | 1.20*** | 1.10–1.32 | 1.20*** | 1.10–1.32 | ||
| Middle School to associate | 1.26*** | 1.11–1.43 | 1.19** | 1.05–1.35 | 1.19** | 1.05–1.35 | ||
| Elementary School or less | 1.36*** | 1.21–1.54 | 1.31*** | 1.16–1.48 | 1.31*** | 1.16–1.48 | ||
| Household income (Ref.: 1st quartile, lowest) | 1 | 1 | 1 | |||||
| 2st quartile | 1.06 | 0.98–1.15 | 1.06 | 0.98–1.15 | 1.06 | 0.98–1.15 | ||
| 3st quartile | 1.09* | 1.01–1.18 | 1.07 | 0.99–1.17 | 1.07 | 0.99–1.17 | ||
| 4st quartile (highest) | 1.15** | 1.06–1.26 | 1.07 | 0.98–1.16 | 1.07 | 0.98–1.17 | ||
| Healthcare covered by NHI (Ref.: Yes) | 1 | |||||||
| No (medical aid) | 2.26*** | 2.01–2.53 | ||||||
| Purchase of PHI (Ref.: No) | 1 | |||||||
| Yes | 1.06 | 0.98–1.15 | ||||||
| NHI status x PHI status (Ref.: Covered by only NHI) | 1 | |||||||
| Covered by only the medical aid | 2.37*** | 2.00–2.75 | ||||||
| Covered by both NHI and PHI | 1.08 | 0.99–1.17 | ||||||
| Covered by both the medical aid and PHI | 2.38*** | 1.97–2.76 | ||||||
Note: NHI National Health Insurance, PHI Private Health Insurance, Dependent variable: used inpatient care during the last year (1); not used inpatient care during the last year (0)
All models are additionally adjusted for age, gender, marital status, and chronic diseases
*p < 0.05
**p < 0.01
***p < 0.001