Table 2. Estimates From Interrupted Time-Series Models of the Impacts of National Negotiation on the Daily Cost, the Monthly Hospital Purchasing Volume and the Monthly Hospital Purchasing Spending for Icotinib and Gefitinib .

Variable	Daily Cost (USD)		Hospital Purchasing Volume (Thousand DDD)		Hospital Purchasing Spending (Million USD)
	β	95% Cl	β	95% Cl	β	95%Cl
Icotinib
Baseline level	64.22c	64.02 to 64.42	40.41c	38.27 to 42.56	2.58c	2.44 to 2.72
Baseline trend	0.04c	0.02 to 0.06	0.89c	0.66 to 1.12	0.06c	0.05 to 0.08
Level change	-14.26c	-16.87 to -11.66	0.81	-5.50 to 7.12	-0.51b	-0.83 to -0.19
Trend change	-1.66c	-2.04 to -1.29	4.87c	4.00 to 5.74	0.02	-0.03 to 0.07
Absolute change	-32.57c	-35.12 to -30.02	54.34c	47.58 to 61.10	-0.26	-0.68 to 0.15
Relative change (%)	-50.08c	-53.80 to -46.36	93.27c	79.24 to 107.31	-6.94	-17.11 to 3.23
Gefitinib
Baseline level	77.96c	77.73 to 78.20	53.24c	48.64 to 57.84	4.12c	3.72 to 4.51
Baseline trend	0.00	-0.02 to 0.02	0.42	-0.08 to 0.92	0.04	0.00 to 0.07
Level change	-32.83c	-37.74 to -27.91	23.23c	13.09 to 33.37	-0.82a	-1.53 to -0.11
Trend change	-0.83b	-1.43 to -0.24	6.89c	5.68 to 8.10	0.16c	0.08 to 0.24
Absolute change	-42.01c	-44.64 to -39.38	99.05c	86.93 to 111.18	0.92a	0.08 to 1.77
Relative change (%)	-53.89c	-57.07 to -50.72	160.50c	126.76 to 194.25	19.16a	0.97 to 37.36

Abbreviation: DDD, defined daily dose.

^a P <.050; ^bP <.010; ^cP <.001.

Absolute change, Relative change: Change at 12 months after policy implementation.