Table 2.

Results of interrupted time series analysis to assess changes in viral testing before and after the COVID-19 pandemic (early and late periods). Results are expressed as a percentage of encounters, with numbers in parenthesis representing 95% confidence intervals.

Sample	Outcome	Prepandemic Slope (Monthly Change)	Early Pandemic (March 15, 2020)		Late Pandemic (January 1, 2023)
			Slope (Monthly Change)	Shift Change	Slope (Monthly Change)	Shift Change
All ED  encounters	Any viral test	0.17 (0.17, 0.18)	0.54 (0.54, 0.55)	4.98 (4.90, 5.07)	0.42 (0.41, 0.42)	-17.80 (−17.90, −17.70)
Multiplex respiratory viral testing
All ED  encounters	Multiplex viral assay	0.05 (0.05, 0.05)	0.60 (0.60, 0.60)	−3.29 (−3.35, −3.23)	0.48 (0.47, 0.48)	−10.17, (−10.24, −10.10)
All ED  encounters	Multiplex viral assay with ≥6 viruses	0.02 (0.02, 0.02)	0.07 (0.07, 0.07)	−0.47 (−0.50, −0.44)	0.20 (0.20, 0.21)	−1.28 (−1.33, −1.25)
Respiratory infection subgroups
Suspected  respiratory  tract infection	Any viral test	0.44 (0.43, 0.45)	0.82 (0.80, 0.83)	12.77 (12.32, 13.21)	0.47 (0.43, 0.51)	−22.55 (−22.01, −21.08)
Bronchiolitis	Any viral test	0.36 (0.35, 0.38)	0.85 (0.82, 0.89)	10.72 (9.74, 11.71)	0.21 (0.13, 0.30)	−17.63 (−18.59, −16.68)
Age-groups
0–1 years	Any viral test	0.26 (0.26, 0.27)	0.70 (0.69, 0.70)	5.21 (5.02, 5.40)	0.51 (0.49, 0.53)	−19.90 (−20.12, −19.67)
2–5 years	Any viral test	0.20 (0.20, 0.20)	0.69 (0.68, 0.70)	2.89 (2.71, 3.08)	0.43 (0.41, 0.44)	−20.45 (−20.67, −20.24)
6–17 years	Any viral test	0.12 (0.12, 0.12)	0.41 (0.40, 0.41)	5.90 (5.79, 6.01)	0.35 (0.34, 0.36)	−15.00 (−15.12, −14.87)

ED, emergency department.