Odds of ever being tested for SARS-CoV-2 and of COVID-19 diagnosis in Ontario between Mar. 1 and June 20, 2020, in fully adjusted analyses using 2 analytic designs
| Determinant | People tested for SARS-CoV-2 | People with a diagnosis of COVID-19* | |
|---|---|---|---|
| Tested v. not tested adjusted OR (95% CI) | Test-positive v. test-negative among all people tested† adjusted OR (95% CI) | Test-positive v. not test-positive‡§ adjusted OR (95% CI) | |
| Sample size | 14 695 579 | 758 691 | 14 695 579 |
| Individual determinant | |||
| Age group, yr (Ref. 0–4) | |||
| 5–19 | 1.15 (1.13–1.18) | 1.93 (1.66–2.24) | 1.72 (1.49–1.99) |
| 20–34 | 4.13 (4.05–4.22) | 2.00 (1.75–2.30) | 7.03 (6.13–8.05) |
| 35–49 | 4.13 (4.05–4.21) | 1.98 (1.73–2.27) | 6.74 (5.88–7.73) |
| 50–64 | 4.21 (4.12–4.29) | 2.02 (1.76–2.32) | 7.01 (6.11–8.03) |
| 65–74 | 3.04 (2.98–3.11) | 1.62 (1.40–1.87) | 3.99 (3.46–4.60) |
| 75–84 | 3.01 (2.95–3.08) | 1.64 (1.41–1.90) | 3.94 (3.39–4.57) |
| ≥ 85 | 5.60 (5.47–5.73) | 1.76 (1.51–2.06) | 7.26 (6.23–8.46) |
| Male sex | 0.76 (0.76–0.76) | 1.26 (1.23–1.30) | 1.00 (0.98–1.03) |
| Living in rural area or small town¶ | 0.97 (0.96–0.98) | 0.81 (0.74–0.88) | 0.76 (0.70–0.82) |
| Underlying chronic health condition | |||
| Asthma | 1.09 (1.09–1.10) | 0.86 (0.83–0.89) | 0.92 (0.89–0.96) |
| COPD | 1.23 (1.21–1.24) | 0.89 (0.82–0.96) | 1.04 (0.96–1.13) |
| Hypertension | 0.98 (0.98–0.99) | 1.12 (1.08–1.16) | 1.13 (1.09–1.17) |
| Diabetes | 0.98 (0.97–0.99) | 1.26 (1.21–1.31) | 1.19 (1.14–1.23) |
| Congestive heart failure | 1.26 (1.24–1.28) | 0.99 (0.92–1.07) | 1.25 (1.16–1.35) |
| Dementia or frailty score > 15 | 2.12 (2.09–2.15) | 1.39 (1.29–1.49) | 2.60 (2.42–2.80) |
| Cancer‡ | 1.13 (1.12–1.15) | 0.72 (0.66–0.80) | 0.86 (0.78–0.94) |
| Chronic kidney disease** | 1.31 (1.29–1.32) | 0.86 (0.80–0.93) | 1.16 (1.08–1.24) |
| Immunocompromised†† | 1.30 (1.28–1.33) | 0.79 (0.70–0.89) | 1.02 (0.91–1.14) |
| Advanced liver disease | 1.14 (1.11–1.16) | 0.79 (0.68–0.90) | 0.87 (0.76–1.00) |
| Ischemic heart disease | 1.02 (1.01–1.03) | 0.88 (0.82–0.95) | 0.90 (0.84–0.97) |
| Ischemic stroke or TIA‡‡ | 1.15 (1.13–1.17) | 1.05 (0.95–1.17) | 1.18 (1.06–1.31) |
| Schizophrenia§§ | 1.24 (1.21–1.27) | 0.84 (0.73–0.97) | 0.99 (0.87–1.13) |
| Substance abuse§§ | 1.17 (1.16–1.19) | 0.72 (0.66–0.79) | 0.86 (0.79–0.95) |
| Health care use | |||
| Aggregated Diagnostic Group (ADG) quintile (Ref. = 0 ADGs) | |||
| 2 (1–2 ADGs) | 1.64 (1.62–1.66) | 0.78 (0.73–0.84) | 1.24 (1.17–1.32) |
| 3 (3–4 ADGs) | 2.07 (2.04–2.10) | 0.75 (0.70–0.80) | 1.46 (1.37–1.56) |
| 4 (5–6 ADGs) | 2.44 (2.41–2.48) | 0.74 (0.69–0.79) | 1.69 (1.57–1.81) |
| 5 (7–27 ADGs) | 3.11 (3.06–3.15) | 0.75 (0.69–0.80) | 2.12 (1.97–2.28) |
| Hospital admissions in the past 3 yr (Ref. = 0 admissions) | |||
| 1 | 0.99 (0.98–1.00) | 0.93 (0.89–0.97) | 0.92 (0.88–0.96) |
| 2 | 1.16 (1.14–1.17) | 0.86 (0.79–0.93) | 1.01 (0.94–1.09) |
| ≥ 3 | 1.75 (1.73–1.78) | 0.82 (0.76–0.90) | 1.38 (1.27–1.50) |
| Outpatient physician visits in the past yr (Ref. = 0–1 visits) | |||
| 2–4 | 1.08 (1.07–1.09) | 1.02 (0.98–1.07) | 1.12 (1.08–1.18) |
| 5–8 | 1.11 (1.10–1.12) | 1.03 (0.98–1.08) | 1.17 (1.11–1.23) |
| 9–14 | 1.17 (1.16–1.18) | 0.98 (0.93–1.04) | 1.17 (1.10–1.24) |
| ≥ 15 | 1.36 (1.34–1.37) | 0.91 (0.85–0.97) | 1.22 (1.14–1.30) |
| Influenza vaccination (2019–2020 season) | 1.08 (1.08–1.09) | 0.81 (0.78–0.83) | 0.87 (0.85–0.90) |
| Environmental determinants¶¶ | |||
| PM2.5 category (μg/m3) (Ref. = 2–6) | |||
| 6–7 | 0.97 (0.97–0.98) | 0.91 (0.85–0.99) | 0.92 (0.85–0.99) |
| 7–8 | 0.92 (0.90–0.93) | 1.10 (0.99–1.21) | 1.00 (0.91–1.10) |
| 8–9 | 0.91 (0.90–0.93) | 1.29 (1.16–1.43) | 1.19 (1.08–1.32) |
| ≥ 10 | 0.90 (0.89–0.92) | 1.45 (1.29–1.63) | 1.31 (1.16–1.47) |
| NO2 category (ppb) (Ref. = 0–6) | |||
| 6–8 | 0.95 (0.95–0.96) | 1.05 (1.00–1.11) | 1.00 (0.96–1.06) |
| ≥ 8 | 0.94 (0.93–0.95) | 1.13 (1.06–1.21) | 1.05 (0.98–1.12) |
| Social determinant of health*** (area level) | |||
| Household density quintile††† (Ref. = first quintile) | |||
| 2 | 1.01 (1.00–1.02) | 1.21 (1.14–1.27) | 1.19 (1.13–1.26) |
| 3 | 1.03 (1.02–1.04) | 1.39 (1.31–1.48) | 1.42 (1.34–1.50) |
| 4 | 1.01 (1.00–1.02) | 1.70 (1.61–1.79) | 1.70 (1.61–1.80) |
| 5 | 0.97 (0.95–0.98) | 1.94 (1.82–2.07) | 1.86 (1.75–1.98) |
| Apartment building density category‡‡‡ (Ref. = first category) | |||
| 2 | 1.04 (1.03–1.04) | 1.00 (0.95–1.04) | 1.02 (0.98–1.06) |
| 3 | 1.01 (1.00–1.02) | 1.15 (1.09–1.21) | 1.18 (1.12–1.24) |
| Uncoupled quintile§§§ (Ref. = first quintile) | |||
| 2 | 1.02 (1.01–1.03) | 0.96 (0.91–1.01) | 0.97 (0.92–1.02) |
| 3 | 1.07 (1.06–1.08) | 0.95 (0.90–1.00) | 0.99 (0.94–1.04) |
| 4 | 1.19 (1.18–1.21) | 0.96 (0.91–1.02) | 1.11 (1.05–1.17) |
| 5 | 1.39 (1.38–1.41) | 1.07 (1.01–1.15) | 1.41 (1.32–1.51) |
| Essential work quintile¶¶¶ (Ref. = first category) | |||
| 2 | 1.04 (1.03–1.04) | 1.25 (1.19–1.32) | 1.30 (1.24–1.37) |
| 3 | 1.06 (1.05–1.07) | 1.28 (1.21–1.35) | 1.37 (1.30–1.45) |
| 4 | 1.05 (1.04–1.06) | 1.37 (1.29–1.45) | 1.51 (1.42–1.60) |
| 5 | 1.04 (1.03–1.06) | 1.42 (1.32–1.51) | 1.58 (1.48–1.69) |
| Household income quintile (Ref. = first quintile, lowest income)**** | |||
| 2 | 1.03 (1.02–1.04) | 0.96 (0.91–1.00) | 1.00 (0.96–1.05) |
| 3 | 1.08 (1.07–1.09) | 1.02 (0.97–1.08) | 1.12 (1.06–1.18) |
| 4 | 1.10 (1.09–1.11) | 0.97 (0.90–1.03) | 1.06 (1.00–1.13) |
| 5 | 1.11 (1.09–1.12) | 0.97 (0.90–1.04) | 1.07 (0.99–1.15) |
| Limited educational attainment quintile†††† (Ref. = first quintile) | |||
| 2 | 1.03 (1.02–1.04) | 1.07 (1.02–1.12) | 1.09 (1.04–1.15) |
| 3 | 1.01 (1.00–1.02) | 1.15 (1.09–1.21) | 1.15 (1.09–1.21) |
| 4 | 1.02 (1.01–1.03) | 1.23 (1.17–1.30) | 1.21 (1.15–1.28) |
| 5 | 1.01 (1.00–1.02) | 1.37 (1.29–1.46) | 1.33 (1.26–1.41) |
| Visible minority quintile‡‡‡‡ (Ref. = first category) | |||
| 2 | 0.99 (0.98–1.00) | 0.96 (0.89–1.02) | 0.95 (0.89–1.02) |
| 3 | 0.95 (0.94–0.96) | 0.97 (0.91–1.05) | 0.93 (0.87–1.00) |
| 4 | 0.91 (0.90–0.92) | 1.07 (0.99–1.15) | 0.98 (0.91–1.06) |
| 5 | 0.86 (0.85–0.87) | 1.27 (1.17–1.38) | 1.09 (1.00–1.19) |
| Recent immigration category§§§§ (Ref. = first category) | |||
| 2 | 0.99 (0.99–1.00) | 1.04 (1.00–1.09) | 1.04 (1.00–1.08) |
| 3 | 0.94 (0.93–0.95) | 1.16 (1.11–1.22) | 1.10 (1.05–1.15) |
Note: ADG = Aggregated Diagnostic Group, COPD = chronic obstructive pulmonary disease, OR = odds ratio, PM2.5 = fine particulate matter, Ref. = reference category, TIA = transient ischemic attack.
↵* All presented models are fully adjusted and contain all variables listed in this table as covariates.
↵† Pseudo-test-negative design.
↵‡ That is, all negative tests and all untested people.
↵§ Case–control design.
↵¶ We defined rural as being located outside the commuting zone of a city with population greater than 10 000.
↵** We counted people if they had a diagnosis in the last 5 years.
↵†† We considered people to be immunocompromised if they were HIV positive, had an organ or bone marrow transplant, or had another immunodeficient condition.
↵‡‡ This category includes people with ischemic stroke or TIA in the last 20 years.
↵§§ This category includes people with a diagnosis in the last 2 years.
↵¶¶ Values of PM2.5 > 12 μg/m3 or NO2 > 53 ppb per year have been found to be associated with increased risk of other respiratory illnesses. (52)
↵*** All variables in this category are area-level variables at the level of the 2016 Canada Census dissemination area (DA).
↵††† First quintile represents 0–2.1 people/dwelling; second quintile, 2.2–2.4 people/dwelling; third quintile, 2.5–2.6 people/dwelling; fourth quintile, 2.7–3 people/dwelling; and fifth quintile, 3.1–5.7 people/dwelling.
↵‡‡‡ First category, 0%–7.3% of buildings in the area are apartment buildings; second category, 7.4%–37.7% are apartment buildings; and third category, 37.7%–100% are apartment buildings.
↵§§§ First quintile, 11.2%–33.7% of people are uncoupled; second quintile, 33.7%–38.4% of people; third quintile, 38.5%–43.6% of people; fourth quintile, 43.6%–51.0% of people; and fifth quintile, 51.0%–94.6% of people.
↵¶¶¶ First quintile represents 0%–32.5% of working people in the area who self-identified as working in an essential job; second quintile, 32.5%–42.3% of people; third quintile, 42.3%–49.8% of people; fourth quintile, 50.0%–57.5% of people; and fifth quintile, 57.5%–114.3% of people.
↵**** Income quintile has variable cut-off values in each city or Census area to take cost of living into account. A DA being in quintile 1 means it is among the lowest 20% of DAs in its city by income.
↵†††† First quintile represents 0%–4.1% of people aged 25–64 years without a diploma; second quintile, 4.1%–7.5% of people; third quintile, 7.5%–11.4% of people; fourth quintile, 11.4%–17.1% of people; and fifth quintile, 17.1%–94.3% of people.
↵‡‡‡‡ First quintile represents 0%–2.2% of people in the area who self-identified as a visible minority; second quintile, 2.2%–7.5% of people; third quintile: 7.5%–18.7% of people; fourth quintile, 18.7%–43.5% of people; and fifth quintile, 43.5%–100% of people.
↵§§§§ First category represents 0%–2.1% of people in a DA being recent immigrants; second category, 2.1%–4.7% of people; and third category, 4.7%–41.2% of people.