Table 1 Effects of the intervention on the cost of antibiotics in comparison with controls: findings from the segmented linear regression models
Outcome indicators | Original models | Models with replaced outliers | ||
|---|---|---|---|---|
Coefficient [95% CI] | p | Coefficient [95% CI] | p | |
Total cost for antibiotics (vs controls) | Â | Â | Â | Â |
 Mean difference in pre-post changes (million yuan) | − 9.02 [− 26.74, 8.69] | 0.312 | − 8.31 [− 18.68, 2.06] | 0.114 |
 Difference in secular trend changes (million yuan per month) | − 1.58 [− 3.20, 0.03] | 0.054 | − 1.56 [− 2.96, − 0.15] | 0.030 |
Cost for non-restricted antibiotics (vs controls) | Â | Â | Â | Â |
 Oral antibiotics (vs controls) |  |  |  |  |
  Mean difference in pre-post changes (million yuan) | − 0.80 [− 5.05, 3.44] | 0.706 | − 0.76 [− 3.56, 2.03] | 0.585 |
  Difference in secular trend changes (million yuan per month) | − 0.36 [− 0.68, − 0.04] | 0.029 | − 0.35 [− 0.61, − 0.079] | 0.012 |
 Antibiotics administered through parenteral route (vs controls) |  |  |  |  |
  Mean difference in pre-post changes (million yuan) | − 7.35 [− 18.71, 4.00] | 0.200 | − 6.61 [− 13.64, 0.42] | 0.065 |
  Difference in secular trend changes (million yuan per month) | − 0.85 [− 1.93, 0.22] | 0.118 | − 0.85 [− 1.80, 0.11] | 0.080 |
Cost for restricted antibiotics (vs controls) | Â | Â | Â | Â |
 Oral antibiotics (vs controls) |  |  |  |  |
  Mean difference in pre-post changes (million yuan) | − 0.74 [− 2.74, 1.26] | 0.463 | − 0.77 [− 1.55, 0.01] | 0.053 |
  Difference in secular trend changes (million yuan per month) | − 0.032 [− .19, 0.121] | 0.675 | − 0.036 [− 0.15, 0.08] | 0.529 |
 Antibiotics administered through parenteral route (vs controls) |  |  |  |  |
  Mean difference in pre-post changes (million yuan) | − 0.63 [− 0.29, 1.63] | 0.577 | − 0.69 [− 2.28, 0.90] | 0.388 |
  Difference in secular trend changes (million yuan per month) | − 0.28 [− 0.52 , − 0.05] | 0.019 | − 0.27 [− 0.49, − 0.06] | 0.015 |