Table 3.
Impact of the DRG System on Use of Outpatient Care and Presurgery Examination (unit: OR/RR)
| Before and After Hospitalization | Before Hospitalization | After Hospitalization | |
|---|---|---|---|
| Before and after hospitalization (any outpatient visits within 30 days) | |||
| Outpatient visit within 30 days1 | |||
| Time effects (after DRG adoption) | 1.07 | 0.95a | 1.32a |
| Organization effect (mandatory adoption of DRG) | 0.68a | 0.71a | 0.65a |
| Net effect | 1.19 | 1.53a | 1.13 |
| Number of outpatient visit within 30 days2 | |||
| Time effects (after DRG adoption) | 1.04a | 0.99 | 1.05a |
| Organization effect (mandatory adoption of DRG) | 0.83a | 0.99 | 0.76a |
| Net effect | 1.12a | 1.14a | 1.15a |
| Outpatient medical expenditure within 30 days (KRW)b 3 | |||
| Time effects (after DRG adoption) | 0.99 | 0.98 | 1.00 |
| Organization effect (mandatory adoption of DRG) | 0.89a | 0.99 | 0.85a |
| Net effect | 1.17a | 1.12a | 1.07a |
| Presurgery examination | |||
| Volume2 | |||
| Basic examination (blood test, EKG, chest X‐ray) | |||
| Time effects (after DRG adoption) | 1.04 | ||
| Organization effect (mandatory adoption of DRG) | 0.93 | ||
| Net effect | 1.20a | ||
| Other examination(except basic examination) | |||
| Time effects (after DRG adoption) | 0.97 | ||
| Organization effect (mandatory adoption of DRG) | 0.96 | ||
| Net effect | 1.24a | ||
| Costs3 | |||
| Basic examination (blood test, EKG, chest X‐ray) | |||
| Time effects (after DRG adoption) | 1.04a | ||
| Organization effect (mandatory adoption of DRG) | 1.12a | ||
| Net effect | 0.99 | ||
| Other examination (except basic examination) | |||
| Time effects (after DRG adoption) | 0.97 | ||
| Organization effect (mandatory adoption of DRG) | 1.01 | ||
| Net effect | 1.11a | ||
Notes: Results are based on difference‐in‐difference estimates. “Time effect” is the impact of the DRG system before and after mandatory adoption. “Organization effect” is the predicted impact on the hospital with no previous adoption of DRG. “Net effect” is the effect of DRG on a newly adopted hospital minus the effects of DRG on a continuously adopted hospital.
Adjusted for age, sex, Charlson comorbidity index, route of hospitalization, length of stay, type of surgery, type of hospital, ownership status, hospital location, teaching status, case mix index, doctors per 100 beds, nurses per 100 beds, hospital beds, and number of hospitalizations.
Statistically significant, p < .05.
1$ = 1091.4 KRW/1GBP = 1707.71 KRW, adjusted for gross price inflation—that is, as if the gross‐to‐cost ratio had stayed constant since 2011. The results of exponential values are those from the gamma regression coefficients.
OR1, odds ratio: Generalized estimating equation model was used in binary outcome variable.
RR2, relative risk: Poisson regression analysis was used in count variable.
RR3, rate ratio: Generalized estimating equation model with gamma distribution was used in cost variable, and it was interpretable as percentage changes.