Table 2. Association between late vs early outbreak identification and SARS-CoV-2 secondary infections and mortality in long-term care home residents, Ontario, Canada, 1 March–14 November 2020 (n = 632 outbreaks).

Variables	Secondary infection incidence				Secondary mortality incidence
	Unadjusted		Adjusteda		Unadjusted		Adjusteda
	OR	95% CI	OR	95% CI	OR	95% CI	OR	95% CI
30-day follow-up
Late (vs early)	3.41	2.24–5.19	2.90	2.04–4.13	3.49	2.26–5.39	2.47	1.77–3.46
Infection pressureb	1.13	1.11–1.16	1.10	1.08–1.12	1.12	1.10–1.14	1.07	1.06–1.09
14-day follow-up
Late (vs early)	5.06	3.04–8.42	4.47	2.98–6.70	6.44	3.92–10.57	4.81	3.12–7.43
Infection pressureb	1.14	1.12–1.17	1.11	1.09–1.13	1.14	1.12–1.17	1.10	1.08–1.12
Full follow-up c
Late (vs early)	2.68	1.79–4.02	2.21	1.55–3.16	2.78	1.84–4.20	1.96	1.42–2.72
Infection pressureb	1.12	1.10–1.15	1.09	1.07–1.11	1.11	1.09–1.13	1.06	1.05–1.08

CI: confidence interval; LTC: long-term care; OR: odds ratio.

^a Adjusted models included the following 12 covariates: beds in the LTC home, LTC home proportion of residents aged ≥ 85 years, proportion of females, proportion with university education, proportion with dementia, average number of comorbidities, average activities of daily living (ADL) impairment scale, crowding index > 2, profit status, prior outbreaks, outbreak identification date (spline with one knot for each month) and public health unit community SARS-CoV-2 incidence.

^b Infection pressure is the number of infectious resident-days occurring in the window from 14 days prior (upper limit on one incubation period) to the outbreak identification date. The numeric value represents the odds ratio associated with a 1-unit increase in infection pressure.

^c Full follow-up defined as time from outbreak identification date until 14 days after the last detected case.