Skip to main content

Table 5 Results of ITS analysis for the change of volume, expenditures, and DDDc of policy-related antihypertensive drugs

From: The impact of “4 + 7” volume-based drug procurement on the volume, expenditures, and daily costs of antihypertensive drugs in Shenzhen, China: an interrupted time series analysis

  Volume Expenditures DDDc
  Coef. 95 % CI Coef. 95 % CI Coef. 95 % CI
Bid-winning drugs       
Baseline change, β0 0.24 (-0.35, 0.83) 0.47 (0.18, 0.77)** 2.04 (1.96, 2.12)***
Baseline trend, β1 0.01 (-0.07, 0.09) 0.02 (-0.02, 0.06) -0.02 (-0.03, -0.01)**
Level change, β2 3.12 (2.14, 4.10)*** 0.93 (0.45, 1.42)** -1.30 (-1.43, -1.18)***
Trend change, β3 0.13 (-0.02, 0.28) 0.01 (-0.06, 0.09) 0.01 (-0.01, 0.03)
R2 0.94   0.85   0.99  
Durbin-Watson d 2.12   2.11   1.91  
Non-winning drugs       
Baseline change, β0 1.66 (1.36, 1.96)*** 5.39 (4.40, 6.38)*** 3.20 (3.09, 3.30)***
Baseline trend, β1 0.09 (0.05, 0.13)*** 0.26 (0.13, 0.39)*** -0.004 (-0.02, 0.01)
Level change, β2 -2.33 (-2.83, -1.82)*** -6.92 (-8.57, -5.28)*** 0.28 (0.11, 0.46)**
Trend change, β3 -0.11 (-0.19, -0.03)** -0.34 (-0.59, -0.09)* 0.01 (-0.02, 0.03)
R2 0.92   0.91   0.65  
Durbin-Watson d 2.20   2.11   2.00  
“4 + 7” List drugs       
Baseline change, β0 1.97 (1.19, 2.74)*** 5.88 (4.73, 7.02)*** 3.06 (2.89, 3.24)***
Baseline trend, β1 0.09 (-0.01, 0.19) 0.28 (0.13, 0.43)** -0.01 (-0.03, 0.02)
Level change, β2 0.95 (-0.33, 2.23) -5.96 (-7.87, -4.04)*** -1.94 (-2.21, -1.66)***
Trend change, β3 0.02 (-0.18, 0.22) -0.33 (-0.62, -0.04)* -0.04 (-0.09, 0.002)
R2 0.74   0.84   0.98  
Durbin-Watson d 2.15   2.15   1.96  
Alternative drugs       
Baseline change, β0 3.91 (3.11, 4.71)*** 12.76 (10.36, 15.17)*** 3.24 (3.18, 3.31)***
Baseline trend, β1 0.16 (0.05, 0.26)** 0.41 (0.10, 0.73)* -0.02 (-0.02, -0.01)**
Level change, β2 -0.91 (-2.24, 0.42) -1.99 (-5.99, 2.02) 0.14 (0.03, 0.25)*
Trend change, β3 0.01 (-0.20, 0.21) -0.01 (-0.62, 0.60) 0.00 (-0.02, 0.01)
R2 0.62   0.56   0.59  
Durbin-Watson d 2.25   2.18   2.03  
Overall policy-related
antihypertensive drugs
      
Baseline change, β0 5.85 (4.49, 7.20)*** 18.59 (15.28, 21.90)*** 3.18 (3.09, 3.27)***
Baseline trend, β1 0.25 (0.07, 0.43)** 0.70 (0.26, 1.13)** -0.01 (-0.02, 0.00)*
Level change, β2 -0.01 (-2.26, 2.25) -8.02 (-13.54, -2.51)** -0.78 (-0.92, -0.63)***
Trend change, β3 0.02 (-0.33, 0.36) -0.35 (-1.19, 0.49) -0.02 (-0.04, 0.004)
R2 0.74   0.47   0.98  
Durbin-Watson d 2.36   2.24   2.35  
  1. DDDc, Defined Daily Drug cost; CI, confidence interval