Table 2

Mean Saturday outpatient volume and billings before and after the introduction of the Saturday incentive programme

	Percentage of Saturday outpatient volume Over total outpatient volume					Percentage of Saturday outpatient billings Over total outpatient billings
	Before		After		p Value	Before		After		p Value
Variables	Mean	SD	Mean	SD	p Value	Mean	SD	Mean	SD	p Value
Region
Group A	13.49	±3.62	13.09	±3.07	0.0489	14.05	±3.83	15.10	±3.59	0.0746
Group B	13.88	±3.08	13.63	±2.63		14.36	±3.29	15.59	±3.11
Group C	13.46	±3.13	13.28	±2.63		13.93	±3.40	15.22	±3.17
Group D	12.62	±2.73	12.37	±2.43		12.66	±2.97	13.78	±2.87
Major treatment area
Internal medicine	13.42	±3.21	13.14	±2.71	0.0896	13.94	±3.48	15.08	±3.25	0.0001
Family medicine	14.00	±3.23	13.86	±2.81		14.24	±3.37	15.73	±3.21
Grade: antibiotic prescription rate
1	13.41	±3.27	13.15	±2.79	0.8537	13.90	±3.50	15.08	±3.32	0.8977
2	13.48	±3.09	13.31	±2.60		13.97	±3.37	15.26	±3.13
3	13.71	±3.07	13.45	±2.60		14.16	±3.32	15.38	±3.11
4	13.64	±3.40	13.32	±2.86		14.06	±3.54	15.24	±3.30
5	13.78	±3.15	13.53	±2.68		14.21	±3.42	15.45	±3.18
Grade: injectable drug prescription rate
1	13.47	±3.51	13.21	±2.95	0.9758	13.99	±3.72	15.26	±3.45	0.9855
2	13.59	±3.24	13.33	±2.73		14.15	±3.53	15.33	±3.32
3	13.52	±3.26	13.30	±2.78		14.02	±3.50	15.23	±3.31
4	13.52	±3.17	13.27	±2.70		13.94	±3.35	15.15	±3.16
5	13.53	±3.07	13.24	±2.65		13.84	±3.30	15.06	±3.07
Grade: kinds of prescribed drugs
1	13.21	±3.46	12.99	±3.07	0.8134	13.61	±3.75	14.70	±3.73	0.1341
2	13.49	±3.37	13.28	±2.84		13.93	±3.61	15.25	±3.31
3	13.62	±3.17	13.41	±2.68		14.12	±3.38	15.41	±3.17
4	13.68	±3.18	13.38	±2.67		14.20	±3.40	15.39	±3.13
5	13.42	±3.08	13.13	±2.63		13.84	±3.31	14.92	±3.13
Age of GP (years)
≤39	13.76	±3.30	13.62	±2.88	0.6081	14.19	±3.63	15.18	±3.44	0.6440
40 to 49	13.72	±3.20	13.48	±2.73		14.22	±3.47	15.41	±3.28
50 to 59	13.59	±3.20	13.35	±2.67		14.05	±3.40	15.31	±3.15
60 to 69	12.77	±3.32	12.47	±2.87		13.20	±3.48	14.42	±3.34
≥70	12.42	±3.37	11.87	±2.82		12.61	±3.54	13.65	±3.28
Months in operation
Up to 5	13.69	±3.38	13.38	±2.92	0.6423	14.32	±3.79	15.28	±3.55	0.0413
6 to 10	13.60	±3.31	13.38	±2.85		14.08	±3.53	15.29	±3.38
11 to 15	13.73	±3.17	13.53	±2.65		14.15	±3.35	15.46	±3.13
16 to 20	13.50	±3.16	13.23	±2.69		13.93	±3.35	15.12	±3.17
21+	12.94	±3.14	12.61	±2.61		13.36	±3.34	14.61	±3.09
Number of nurses
0	13.60	±3.25	13.32	±2.78	0.1121	14.08	±3.48	15.34	±3.25	0.0249
1	13.66	±3.21	13.39	±2.67		14.22	±3.44	15.38	±3.17
2 to 5	12.94	±3.10	12.87	±2.65		13.18	±3.33	14.24	±3.26
6+	12.14	±2.76	12.36	±2.64		11.98	±2.81	12.42	±2.96
Outpatient volume (per month)
≤999	13.45	±3.77	13.16	±3.21	0.7139	13.90	±4.18	15.01	±3.91	0.5191
1000 to 1999	13.66	±3.25	13.40	±2.76		14.18	±3.48	15.38	±3.29
≥2000	13.41	±3.04	13.19	±2.59		13.82	±3.22	15.07	±3.01
Total outpatient billings (KRW10 000 per month)
≤1.999	13.73	±3.55	13.41	±3.04	0.2584	14.18	±3.80	15.48	±3.54	0.0371
2.000 to 2.999	13.74	±3.20	13.47	±2.66		14.27	±3.41	15.54	±3.11
≥3.000	13.26	±3.05	13.07	±2.62		13.70	±3.30	14.80	±3.16
Total	13.53	±3.24	13.28	±2.75		14.00	±3.47	15.21	±3.26

GP, general practitioner.