Table 1.

General Characteristics of Participants (n = 1,029,101) (Unit: N/M, %/SD, KRW)

	Introduction of DRG				p‐Value
	Before (n = 422,153)		After (n = 606,948)
Outcome variable (any outpatient visits within 30 days)
Outpatient visit within 30 days
Total	384,609	(91.1)	558,499	(92.0)	<.0001
Before hospitalization	276,825	(65.6)	375,425	(61.9)	<.0001
After discharge from hospital	354,693	(84.0)	537,509	(88.6)	<.0001
Number of outpatient visit within 30 days (before and after hospitalization)
Total	3.46	±2.58	3.92	±2.66	<.0001
Before hospitalization	0.91	±0.91	0.82	±0.85	<.0001
After discharge from hospital	2.55	±2.40	3.10	±2.46	<.0001
Outpatient medical expenditure within 30 daysa
Total	100,161	95,837	94,926	72,459	<.0001
Before hospitalization	62,285	72,318	51,723	60,164	<.0001
After discharge from hospital	37,876	61,719	43,203	39,380	<.0001
Presurgery examination before hospitalization
Volume
Basic examination(blood test, EKG, chest X‐ray)	8.65	±9.40	7.70	±8.93	<.0001
Other examination	5.36	±6.37	4.22	±5.27	<.0001
Costs
Basic examination(blood test, EKG, chest X‐ray)	13,159	14,609	11,348	13,531	<.0001
Other examination	25,122	33,695	21,110	28,040	<.0001
Patients characteristics
Sex
Male	256,987	(60.9)	362,200	(59.7)	<.0001
Female	165,166	(39.1)	244,748	(40.3)
Age	38.18	±19.24	40.43	±16.90	<.0001
CCI
0	218,258	(51.7)	302,940	(49.9)	<.0001
1	85,486	(20.3)	132,490	(21.8)
2	61,797	(14.6)	99,167	(16.3)
≥3	56,612	(13.4)	72,351	(11.9)
LOS	3.47	±2.28	2.89	±1.50	<.0001
Route of hospitalization
ER	738	(0.2)	3,006	(0.5)	<.0001
Outpatient clinic	421,415	(99.8)	603,942	(99.5)
Type of surgery
Tonsillectomy and adenoidectomy	67,002	(15.9)	44,357	(7.3)	<.0001
Inguinal and femoral hernia operation	50,659	(12.0)	38,164	(6.3)
Hemorrhoidectomy	304,492	(72.1)	524,427	(86.4)

^a1$ = 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.

CCI, Charlson comorbidity index; EKG, electrocardiogram; LOS, length of stay.