Does an economic incentive affect provider behavior? Evidence from a field experiment on different payment mechanisms

Figures & data

Table 1. FFS (K = A, J = 1).

Number	Medical services	Treatment charge	Treatment cost	Physician benefit	Patient benefit
0	0	0	0	0	0
1	A1	5.1	1.2	3.9	1
2	A1, A2	10.2	2.4	7.8	1.5
3	A1, A2, A3	15.3	3.6	11.7	10
4	A1, A2, A3, A4	17.4	4.8	12.6	9.5
5	A1, A2, A3, A4, A5	31.6	6	25.6	9
6	A1, A2, A3, A4, A5, A6	32.8	7.2	25.6	8.5
7	A1, A2, A3, A4, A5, A6, A7	34.28	8.4	25.88	8
8	A1, A2, A3, A4, A5, A6, A7, A8	35.9	9.6	26.3	7.5
9	A1, A2, A3, A4, A5, A6, A7, A8, A9	37.7	10.8	26.9	7
10	A1, A2, A3, A4, A5, A6, A7, A8, A9, A10	40	12	28	6.5

Table 2. Sample of physicians and numbers of collected questionnaires.

Sample hospitals	Participating physicians	Questionnaires collected	Valid return
Jiangsu Province Hospital	22	990	945
Jiangsu Province Hospital of Traditional Chinese Medicine	20	900	900
The Second Affiliated Hospital of Nanjing Medical University	21	945	900
Second Hospital of Jiangsu Province	19	855	810
Nanjing Integrated Traditional Chinese and Western Medicine Hospital	20	900	765
Zhongda Hospital Southeast University	21	945	945
Nanjing First Hospital	22	990	945
Nanjing Drum Tower Hospital The Affiliated Hospital of Nanjing University Medical School	22	990	855
Nanjing Hospital of Chinese Medicine, The Third Hospital of Nanjing University of Chinese Medicine	21	945	900
The Second Hospital of Nanjing	21	945	945
Planned sampling	220	9,900	9,900
Practical sampling	209	9,405	8,910

Table 3. Quantity of medical services provided by physicians under different payment systems.

	Group	Mean	SD	Maximum	Minimum	Sig
Payment systems	FFS	5.4	1.532	10	1	0
	CAP	5.085	1.433	9	1
	DRG	4.702	1.333	10	2
State of health	Good	3.954	1.421	10	1	0
	Intermediate	5.251	0.996	10	2
	Bad	6.054	1.1	9	3
Illness type	A	5.01	1.418	10	1	0.793
	B	5.086	1.482	9	2
	C	5.111	1.478	10	1
	D	5.088	1.472	9	1
	E	5.139	1.493	10	3

Table 4. Influences of FFS and CAP on physicians’ provision of medical services for patients with the same level of health.

	FFS		CAP
	Mean	SD	Mean	SD	Sig
Good	4.268	1.612	4.098	1.494	0.462
Intermediate	5.447	1	5.315	1.056	0.955
Bad	6.485	0.997	5.842	1.108	0.331

Figure 1 Relationship between the average quantity of medical services and the optimal quantity of medical services under FFS.

Figure 2 Relationship between average quantity and optimal quantity of medical services under CAP.

Figure 3 Relationship between average and optimal quantity of medical services under DRGs.

Figure 4 Loss of health benefits to patients with the same level of health.

Table 5. Impacts of patient health status on loss of health benefits under the same payment system.

	Good		Intermediate		Bad
	Mean	SD	Mean	SD	Mean	SD	Sig.
FFS	0.103	0.179	0.087	0.106	0.115	0.102	0.001
CAP	0.057	0.089	0.076	0.113	0.114	0.114	0.000
DRG	0.2	0.398	0.052	0.152	0.059	0.132	0.000

Table 6. Quantity of medical services provided by physicians for patients with different illnesses and with the same health status.

	A		B		C		D		E
Health status	Mean	SD	Mean	SD	Mean	SD	Mean	SD	Mean	SD	Sig
Good	3.447	0.76	3.336	0.785	3.447	0.86	3.342	0.708	3.342	0.745	0.946
Intermediate	4.921	1.049	4.686	0.875	4.894	0.649	4.984	0.764	5.078	0.127	0.817
Bad	5.631	0.882	5.631	1.195	5.947	0.928	5.684	1.36	6.026	1.052	0.305