Table 3.

Results of interrupted time series analysis for respiratory viral testing before and during the COVID-19 pandemic (early and late periods). Results are expressed in US dollars (adjusted to 2023 dollars using the consumer price index), with numbers in parentheses representing 95% confidence intervals.

			Early Pandemic (March 15, 2020)		Late Pandemic (January 1, 2023)
Sample	Outcome	Prepandemic Slope (Monthly Change)	Slope (monthly change)	Shift change	Slope (monthly change)	Shift change
All ED  encounters	Any viral test	5,000 (4,200, 5,700)	33,000 (32,000, 34,000)	−250,000, (−270,000, −220,000)	27,000 (24,000, 30,000)	−580,000 (−620,000, −540,000)
Multiplex respiratory pathogen panel
All ED  encounters	Multiplex viral assay	2,800 (2,100, 3,400)	23,000 (22,000, 24,000)	−200,000 (−220,000, −180,000)	31,000 (28,000, 34,000)	−370,000 (−410,000, −340,000)
All ED  encounters	Multiplex viral assay with ≥6 viruses	1,600 (1,400, 1,800)	3,300 (3,000, 3,600)	−59,000 (−66,000, −51,000)	15,000 (14,000, 16,000)	−55,000 (−65,000, −45,000)
Respiratory infection subgroups
Suspected  respiratory  tract infection	Any viral test	3,000 (2,500, 3,500)	19,000 (18,000, 19,000)	190,000 (−200,000, −170,000)	23,000 (20,000 25,000)	−380,000 (−400,000, −350,000)
Bronchiolitis	Any viral test	390 (200, 480)	2,400 (2,300, 2,500)	−29,000 (−32,000, −26,000)	2,900 (2,500, 3,300)	−48,000 (−52,000, −43,000)
Age-stratified models
0–1 years	Any viral test	1,900, (1,700, 2,200)	11,000 (11,000, 11,000)	−86,000 (−95,000, −78,000)	9,800 (8,800, 11,000)	−200,000 (−210,000, −180,000)
2–5 years	Any viral test	1,300 (1,100, 1,500)	9,800 (9,500, 10,000)	−80,000 (−87,000, −73,000)	5,000 (4,300, 6,100)	−170,000 (−170,000, −160,000)
6–17 years	Any viral test	1,700 (1,400, 2,000)	13,000 (12,000, 13,000)	−85,000 (−98,000, −73,000)	12,000 (10,000, 13,000)	−220,000 (−240,000, −210,000)