Table 2

Changes in levels and trends of and absolute and relative changes in medication cost per DDD, procurement volume and spending, for 2017 price-negotiated and comparison group medications

2017 negotiation medications	2017 price-negotiated medications			Comparison group medications			Change relative to comparison group
2017 negotiation medications	Coefficient	P value	95% CI	Coefficient	P value	95% CI	Coefficient	P value	95% CI
Cost per DDD (US$/DDD)*
Baseline level	215.58	0.000	204.37 to 226.80	274.83	0.000	267.18 to 282.48	−59.16	0.000	−68.55 to −49.77
Baseline trend	−2.24	0.000	−3.11 to −1.37	−1.71	0.000	−2.35 to −1.07	−0.29	0.463	−1.08 to 0.50
Level change after intervention	−71.21	0.000	−81.56 to −60.85	1.54	0.801	−10.81 to 13.89	−87.69	0.000	−102.76 to −72.61
Trend change after intervention	−0.95	0.316	−2.85 to 0.95	−0.24	0.723	−1.63 to 1.14	−0.05	0.951	−1.75 to 1.64
Absolute change at 6 months after intervention	−76.91	0.000	−90.25 to −63.57	0.08	0.989	−11.60 to 11.76	−88.00	0.000	−102.32 to −73.68
Relative change at 6 months after intervention	−48.88	0.000	53.71 to 44.04	0.04	0.989	4.82 to 4.89	−32.94	0.000	−36.24 to −29.64
Absolute change by end of observation period	−83.56	0.000	−107.86 to −59.27	−1.62	0.848	−18.70 to 15.47	−88.36	0.000	−109.37 to −67.36
Relative change by end of observation period	−58.99	0.000	69.05 to 48.92	−0.74	0.846	8.19 to 6.71	−33.33	0.000	−38.55 to −28.11
Volume (no of DDDs)*
Baseline level	23.69	0.000	20.01 to 27.37	8.76	0.000	7.83 to 9.70	14.92	0.000	11.21 to 18.64
Baseline trend	0.86	0.000	0.55 to 1.17	0.22	0.000	0.14 to 0.30	0.64	0.000	0.33 to 0.95
Level change after intervention	9.38	0.003	3.45 to 15.31	−1.11	0.143	−2.62 to 0.40	10.49	0.001	4.51 to 16.48
Trend change after intervention	4.99	0.000	4.33 to 5.66	−0.21	0.017	−0.38 to −0.04	5.20	0.000	4.53 to 5.88
Absolute change at 6 months after intervention	39.35	0.000	33.73 to 44.97	−2.36	0.002	−3.79 to −0.94	41.72	0.000	36.04 to 47.39
Relative change at 6 months after intervention	85.59	0.000	65.26 to 105.93	−16.41	0.000	−24.65 to −8.18	164.19	0.000	82.47 to 245.92
Absolute change by end of observation period	74.31	0.000	66.09 to 82.54	−3.83	0.001	−5.92 to −1.74	78.14	0.000	69.84 to 86.45
Relative change by end of observation period	142.98	0.000	110.18 to 175.78	−24.04	0.000	−34.47 to −13.62	261.47	0.000	134.94 to 387.99
Spending (US$)*
Baseline level	5279.02	0.000	4892.18 to 5665.86	2408.59	0.000	2199.23 to 2617.96	2879.15	0.000	2449.58 to 3308.72
Baseline trend	97.36	0.000	64.96 to 129.76	38.78	0.000	21.25 to 56.31	57.75	0.002	21.77 to 93.73
Level change after intervention	−2347.96	0.000	−2972.24 to −1723.67	−270.61	0.110	−606.29 to 65.07	−2061.56	0.000	−2754.26 to −1368.86
Trend change after intervention	135.79	0.000	65.81 to 205.77	−62.48	0.002	−100.30 to −24.65	198.35	0.000	120.66 to 276.05
Absolute change at 6 months after intervention	−1533.22	0.000	−2123.59 to −942.85	−645.46	0.000	−964.59 to −326.33	−871.43	0.010	−1526.98 to −215.87
Relative change at 6 months after intervention	−19.63	0.000	−25.72 to −13.54	−18.89	0.000	−26.46 to −11.32	−22.32	0.000	−34.13 to −10.51
Absolute change by end of observation period	−582.68	0.178	−1446.50 to 281.13	−1082.79	0.000	−1551.16 to −614.41	517.06	0.285	−442.46 to 1476.58
Relative change by end of observation period	−6.86	0.146	−16.12 to 2.39	−29.36	0.000	−38.99 to −19.72	12.00	0.346	−12.98 to 36.98

US$ in 2016
*Except for relative changes which are expressed in percent.
CI, confidence interval; DDD, defined daily doses.