Table 4.

Impact of the intervention on the reduction in cost (in euro) of antibiotics across follow-up (median 19 months)^a

	% change in costa			Changes in cost (in euro) across follow-up, attributable to the intervention b
	%	95%CI	p-value	€	95%CI
Reduction in absolute direct costs attributable to the intervention
Costs for the Spanish NHS in Galicia	−2.88	−3.97 to − 1.8	< 0.0001	− 378,061	− 518,186 to − 237,936
Total costs	−4.33	−5.38 to − 3.29	< 0.0001	− 697,381	− 861,794 to − 533,216
Reduction in direct costs per physician, attributable to the intervention
Cost for the Spanish NHS in Galicia	−2.88	− 3.97 to −1.8	< 0.0001	−311	− 426 to − 196
Total costs	−4.33	− 5.38 to − 3.29	< 0.0001	− 573	− 708 to − 438
Reduction in direct costs per 1000 inhabitants, attributable to the intervention
Cost for the Spanish NHS in Galicia (1000 inhabitants)	−2.43	−3.55 to − 1.33	< 0.0001	− 205.8	− 298.5 to − 113.1
Total costs (1000 inhabitants)	− 4.46	− 5.54 to − 3.4	< 0.0001	− 464.7	− 573 to − 356.4

^a Calculated from a mixed-effects model. The estimated value for intervention measures is an interaction between the variable “group” (intervention vs. control) and the variable “period” (post-intervention vs. baseline), adjusted for secular trend of the indicator

^b Calculated by taking the total cost of antibiotics for the control group at baseline as reference