. 2022 Oct 29;48(8):672–677. doi: 10.5271/sjweh.4056

Table 1.

Incidence rate ratio (IRR) with 95% confidence intervals (CI) for COVID-19 related hospital admission within at-risk industrial sectors¹across pandemic waves and between at-risk industrial sectors in comparison with a COVID-19 job exposure matrix (JEM)-based reference group.

Occupations Within and between group difference	DB07 code	All waves			Wave 1 week 8–32 2020 (Alpha variant)			Wave 2 week 33–52 2021, 1-4 2021 (Alpha variant)			Wave 3 week 5–26 2021 (Beta variant)			Wave 4 week 27–50 2021 (Delta variant)			Test for trend ²/interaction ³

		N	IRR	95% CI	N	IRR	95% CI	N	IRR	95% CI	N	IRR	95% CI	N	IRR	95% CI	P-value
Healthcare	85	314			102			120			42			50
Within ²			-	-		1.00			1.23	1.0-1.6		0.47	0.3-0.7		0.52	0.4-0.7	<0.0001
Between ³			1.66	1.4-1.9		3.59	2.7-4.9		1.64	1.3-2.1		0.94	0.7-1.3		1.19	0.9-1.7	<0.0001
Social care	87–88	628			95			251			117			165
Within ²			-	-		1.00			2.76	2.2-3.5		1.41	1.1-1.9		1.82	1.4-2.4	<0.0001
Between³			1.40	1.2-1.6		1.51	1.1-2.1		1.45	1.2-1.8		1.09	0.9-1.4		1.58	1.2-2.0	0.069
Education	86	226			22			89			58			57
Within ²			-	-		1.00			4.24	2.7-6.8		3.02	1.9-4.9		2.72	1.7-4.5	<0.0001
Between ³			1.31	1.1-1.5		0.80	0.5-1.3		1.30	1.0-1.7		1.43	1.1-2.0		1.60	1.2-2.2	0.185
Transport	49-51	128			17			42			46			23
Within ²			-	-		1.00			2.60	1.5-4.6		3.10	1.8-5.5		1.44	0.8-2.7	<0.0001
Between ³			1.85	1.5-2.3		1.69	1.0-2.9		1.44	1.0-2.0		2.73	1.9-3.9		1.77	1.1-2.8	0.051
Retail sales	46	120			12			44			24			40
Within ²						1.00			3.83	2.0-7.3		2.29	1.1-4.6		3.49	1.8-6.7	<0.0001
Between ³			1.01	0.8-1.2		0.93	0.5-1.7		1.09	0.8-1.5		0.84	0.5-1.3		1.13	0.8-1.6	0.037
Service trades	55, 56, 81, 93, 96	213			21			83			63			46
Within ²			-	-		1.00			4.16	2.6-6.7		3.46	2.1-5.7		2.32	1.4-3.9	<0.0001
Between ³			0.93	0.8-1.1		0.78	0.5-1.3		0.97	0.8-1.2		1.09	0.8-1.5		0.78	0.6-1.1	0.160
Others⁴		1535			216			531			422			366
Within ²			-	-		1.00			2.58	2.2-3.0		2.24	1.9-2.6		1.78	1.5-2.1	<0.0001
Between ³			0.94	0.9-1.0		0.91	0.7-1.2		0.80	0.7-0.9		1.09	0.9-1.3		1.08	0.9-1.3	0.065
Missing DISCO-08 code		693			76			224			183			210
Within ²			-			1.00			3.10	2.4-4.0		2.77	2.1-3.6		2.92	2.3-3.8	<0.0001
Between ³			1.15	1.0-1.3		0.94	0.7-1.3		0.97	0.8-1.2		1.25	1.0-1.6		1.48	1.2-1.9	<0.0001
JEM-based reference group ³		559	1.0		83	1.00		224	2.84	2.2-3.7	133	1.84	1.4-2.4	118	1.49	1.1-2.0	<0.0001

Industrial sectors at the 2-digit DB07 level with a higher likelihood of occupational SARS-CoV-2 exposure according to an expert rated COVID-19 job exposure matrix (sumscore >12, range 0-24) (9).

Crude risk across pandemic waves within each group of occupations relative to the occurrence in the first wave. P-values for test of non-linear trend in risk across waves (within industrial sector comparisons).

Wave-specific risk adjusted for sex, age (10 year groups), duration of education at baseline (5 groups), number of hospital admissions for one or more of 11 chronic diseases in the 10 years preceding start of the pandemic (0, 1, >1), country of origin (4 categories) and geographical region (5 groups) in an at-risk industrial sector compared with a COVID-19 JEM reference group (9) (all employees with low likelihood of occupational SARS-CoV-2 exposure (sumscore for all eight rated measures = 0)). P-values for interaction testing if the pandemic wave modified the effect of industrial sector on risk of COVID-19 hospital admission (between industrial sector comparisons).

⁴

Employees in other industrial sectors and employees with COVID-19 JEM sumscore ≤12.