The association of facility ownership with COVID-19 outbreaks in long-term care homes in British Columbia, Canada: a retrospective cohort study

Michelle B. Cox; Margaret J. McGregor; Jeffrey Poss; Charlene Harrington

doi:10.9778/cmajo.20220022

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Table 1:

Characteristics of COVID-19 outbreaks in long-term care facilities between Mar. 1, 2020, and Jan. 31, 2021, in British Columbia

Characteristic	No. (%) of total^*
COVID-19 outbreaks
Total outbreaks^†	94
Wave 1^‡	18 (19.1)
Wave 2^‡	76 (80.9)
No. of residents involved in outbreak
1	14 (14.9)
2–10	28 (29.8)
11–50	34 (36.2)
> 50	18 (19.1)
At least 1 resident death	75 (79.8)
Length of outbreak, d, mean ± SD	47.2 ± 18.6
Range	5.0–106.0
No. of outbreaks by health authority
Vancouver Coastal Health	25 (26.6)
Fraser Health	55 (58.5)
Interior Health	9 (9.6)
Island Health	2 (2.1)
Northern Health	3 (3.2)
LTC facilities
Total facilities	293
Facilities with outbreaks	80 (27.3)
No outbreaks	213 (72.7)
1 outbreak	66 (22.5)
2 outbreaks	14 (4.8)
Facilities by health authority
Vancouver Coastal Health	54 (18.4)
Fraser Health	80 (27.3)
Interior Health	79 (27.0)
Island Health	58 (19.8)
Northern Health	22 (7.5)
COVID-19 cases among LTC residents^‡
Total resident cases	2379
Resident cases per outbreak facility, mean ± SD	29.7 ± 26.9
Total resident deaths	749
COVID-19 case mortality rate (resident deaths per resident COVID-19 cases)	749 (31.5)
Resident cases by health authority
Vancouver Coastal Health	764 (32.1)
Fraser Health	1286 (54.1)
Interior Health	231 (9.7)
Island Health	8 (0.3)
Northern Health	90 (3.8)
Community rates of COVID-19
Health authority daily incidence, infections per 100000 population^¶
Vancouver Coastal Health	4.14
Fraser Health	6.75
Interior Health	2.52
Island Health	0.76
Northern Health	4.20

Note: LTC = long-term care, SD = standard deviation.
↵* Unless indicated otherwise.
↵† An outbreak at a facility was declared when COVID-19 was diagnosed in 1 or more LTC residents by laboratory-confirmed SARS-CoV-2 infection.
↵‡ Wave 1: Mar. 1, 2020, to July 31, 2020; wave 2: Aug. 1, 2020, to Jan. 31, 2021.
§ A COVID-19 case refers to an LTC facility resident with laboratory-confirmed SARS-CoV-2 infection.
↵¶ Average daily incidence (Mar. 1, 2020, to Jan. 31, 2021) calculated from laboratory-diagnosed or episode-linked case tallies by health authority in BC.

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Table 2:

Characteristics of long-term care facilities in British Columbia by presence of a COVID-19 outbreak between Mar. 1, 2020, and Jan. 31, 2021

Characteristic	No. (%) of facilities^*			p value^†
Characteristic	All facilities n = 293	Facilities with outbreaks n = 80	Facilities with no outbreaks n = 213	p value^†
Total beds	29 095	9919	19 176
Ownership characteristics^‡
For-profit	105 (35.8)	37 (46.3)	68 (31.9)	0.003
Nonprofit	82 (28.0)	25 (31.3)	57 (26.8)	0.029
Health authority	106 (36.2)	18 (22.5)	88 (41.3)	Ref.
Community characteristics
Facility-weighted COVID-19 community incidence (infections per 100 000 population),^§^¶ median (IQR)	4.14 (2.52–6.75)	6.75 (4.14–6.75)	2.52 (0.76–4.14)	< 0.0001
Staffing characteristics
Staffing hours^**
Total nursing or care aide hours, mean ± SD	2.98 ± 0.35	2.90 ± 0.20	3.01 ± 0.39	0.003
Total allied health hours, mean ± SD	0.32 ± 0.10	0.32 ± 0.07	0.32 ± 0.11	0.691
Missing	1	0	1
Subcontracted services
Professional nursing services	69 (23.6)	27 (33.8)	42 (19.7)	0.012
Nonregulated services (care aides)	69 (23.6)	26 (32.5)	43 (20.2)	0.027
Any food services	109 (37.8)	38 (48.1)	71 (34.0)	0.027
Missing	5	1	4
Facility characteristics
Age of facility, yr, mean ± SD	30.3 ± 16.3	31.3 ± 15.9	29.9 ± 16.4	0.494
Beds per facility, mean ± SD	99.3 ± 56.1	124.0 ± 56.9	90.0 ± 53.0	< 0.0001
Facilities with beds in shared rooms	174 (59.4)	58 (72.5)	116 (54.5)	0.005
Large proportion of beds in shared rooms^†† (v. small or none)	88 (30.0)	30 (37.5)	58 (27.2)	0.088
Resident characteristics
Facility-weighted age of population,^§ yr, mean ± SD	83.8 ± 32.5	84.2 ± 26.6	83.6 ± 34.4	0.139
Missing	3	0	3
Facility-weighted proportion of male residents,^§ median (IQR)	0.35 (0.29–0.41)	0.35 (0.29–0.42)	0.35 (0.30–0.40)	0.613
Missing	3	0	3
Facility-weighted case mix index,^§ mean ± SD	0.58 ± 0.38	0.58 ± 0.35	0.58 ± 0.39	0.543
Missing	4	1	3

Note: IQR = interquartile range, Ref. = reference category, SD = standard deviation.
↵* Unless indicated otherwise.
↵† Tests of comparison include the Welch t-test and Mann–Whitney U test for continuous variables, and the χ² test for categorical variables.
↵‡ For-profit facilities include those owned and operated by for-profit corporations. Nonprofit facilities include those owned and operated by independent (nongovernment) nonprofit societies. Health authority facilities include those owned and operated by the provincial health authorities in British Columbia.
↵§ Variable is weighted by size of facility.
↵¶ Average daily incidence (Mar. 1, 2020, to Jan. 31, 2021) calculated from laboratory-diagnosed or episode-linked case tallies by health authority in BC.
↵** Nursing or care aide hours includes registered nurse hours, licensed practical nurse hours and care aide hours (average number of hours for entire facility, not how many hours each resident receives). Allied health includes physical, occupational, recreation, speech and language therapies, as well as social work services and dietitians.
↵†† Large proportion of beds in shared rooms = greater than 20% of total beds are in shared rooms.

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Table 3:

Multivariable regression analysis of ownership and other characteristics associated with COVID-19 outbreaks in long-term care facilities in British Columbia, Mar. 1, 2020, to Jan. 31, 2021

Characteristic	Univariate models Unadjusted HR (95% CI)	Model 1 Adjusted HR (95% CI)	Model 2 Adjusted HR (95% CI)	Model 3 Adjusted HR (95% CI)
Ownership
For-profit	2.17 (1.38–3.41)	1.90 (1.14–3.18)	1.72 (0.99–2.98)	1.99 (1.12–3.52)
Nonprofit	2.28 (1.39–3.73)	2.13 (1.21–3.75)	1.93 (1.06–3.50)	1.84 (1.00–3.36)
Health authority	Ref.	Ref.	Ref.	Ref.
Time-varying community incidence of COVID-19 (infections per 100 000 population)	1.14 (1.10–1.19)	1.13 (1.09–1.18)	1.13 (1.08–1.18)	1.12 (1.07–1.17)
Total nursing or care aide hours per resident-day	0.20 (0.07–0.59)		0.69 (0.26–1.83)	0.84 (0.33–2.14)
Facility age, yr	1.01 (1.00–1.02)			1.01 (1.00–1.02)
No. of beds per facility (per 25 beds)	1.20 (1.13–1.26)			1.20 (1.12–1.30)
Facilities with beds in shared rooms	1.56 (1.03–2.36)			1.16 (0.73–1.85)

Note: CI = confidence interval, HR = hazard ratio, Ref. = reference category.
* Model 1 adjusted for community incidence of COVID-19. Model 2 adjusted for incidence and staffing characteristics. Model 3 adjusted for incidence, and staffing and facility characteristics.