Table 1.

Sensitivity analyses of estimating the effect of the ASP implementation on the rate of carbapenem prescription for various types of model specifications

Outcome being modelled	Poisson model specifications	IRR	95% CI	P value
Monthly rate of carbapenem-treated patients, per 100 hospital admissions	Unadjusted	0.70	0.56–0.87	0.002
	Adjusted for seasonality	0.63	0.50–0.80	<0.001
	Adjusted for seasonality, overdispersion	0.63	0.39–1.01	0.056
Monthly rate of carbapenem-treated patients, per 100 inpatients	Unadjusted	0.71	0.57–0.88	0.002
	Adjusted for seasonality	0.69	0.55–0.86	0.001
	Adjusted for seasonality, overdispersion	0.69	0.44–1.08	0.103
Monthly rate of carbapenem-treated patients, per 1000 PD	Unadjusted	0.68	0.55–0.85	0.001
	Adjusted for seasonality	0.71	0.57–0.88	0.002
	Adjusted for seasonality, overdispersion	0.71	0.46–1.08	0.107