Table 4.

For each sex and age category strata, an interrupted time series of weekly emergency medical service calls for overdose from January 2019 to July 2020 using negative binomial regression offset by the total population, for regions in the United Kingdom and in Canada.^a

Strata and variable			East Midlands region, United Kingdom	Niagara and Hamilton regions, Canada
Sex
	Female
		Attendances, n	29,939	4646
		Per week, IRRb (95% CI)	1.003 (1.002-1.004) c	1.002 (1.001-1.003)
		Lockdown, IRR (95% CI)	0.535 (0.474-0.604)	0.906 (0.723 1.134)
		Lockdown trend, IRR (95% CI)	1.036 (1.024-1.048)	1.005 (0.984-1.027)
	Male
		Attendances, n	34,516	6973
		Per week, IRR (95% CI)	1.002 (1.001-1.002)	1.001 (1.000-1.002)
		Lockdown, IRR (95% CI)	0.612 (0.547-0.685)	0.674 (0.522-0.872)
		Lockdown trend, IRR (95% CI)	1.028 (1.017-1.039)	1.021 (0.996-1.046)
Age
	<18 years
		Attendances, n	5385	630
		Per week, IRR (95% CI)	1.003 (1.002-1.004)	0.997 (0.994-0.999)
		Lockdown, IRR (95% CI)	0.456 (0.369-0.564)	0.845 (0.469-1.469)
		Lockdown trend, IRR (95% CI)	1.051 (1.031-1.071)	1.007 (0.954-1.006)
	18-44 years
		Attendances, n	37,314	7645
		Per week, IRR (95% CI)	1.002 (1.002-1.003)	1.002 (1.001-1.003)
		Lockdown, IRR (95% CI)	0.572 (0.505-0.647)	0.703 (0.560-0.882)
		Lockdown trend, IRR (95% CI)	1.030 (1.019-1.042)	1.013 (0.991-1.035)
	45-65 years
		Attendances, n	17,313	2826
		Per week, IRR (95% CI)	1.002 (1.002-1.003)	1.003 (1.000-1.004)
		Lockdown, IRR (95% CI)	0.583 (0.518-0.656)	0.883 (0.638-1.223)
		Lockdown trend, IRR (95% CI)	1.031 (1.020-1.042)	1.019 (0.988-1.051)
	>65 years
		Attendances, n	4820	518
		Per week, IRR (95% CI)	1.003 (1.002-1.004)	1.000 (0.997-1.003)
		Lockdown, IRR (95% CI)	0.700 (0.577-0.848)	0.855 (0.467-1.511)
		Lockdown trend, IRR (95% CI)	1.024 (1.007-1.042)	0.996 (0.929-1.053)

^aModels have been adjusted for seasonality (each month as a variable).

^bIRR: incidence rate ratio.

^cIRRs statistically significant at P<.05 are indicated in italics format.