Table 2.

Coefficients from the primary interrupted time series model.

Term	Estimate (β)	Std. Error	p-value	Interpretation
(Intercept)	593.0	39.1	<0.001	Baseline level (2018 Q1)
Time	61.7	7.6	<0.001	Pre-intervention trend per quarter
Intervention1 (2020 Q4)	2,317.4	631.8	0.001	Immediate level change post-EUA
Time: Intervention1	−119.5	24.2	<0.001	Change in trend post-EUA

Results from the primary segmented linear regression model. Newey-West standard errors (lag = 3) were used to account for autocorrelation. R² = 0.48. EUA = Emergency Use Authorization. Significance codes: ^***p < 0.001, ^*p < 0.05.