Determinants of self-reported symptoms and testing for 1 COVID in Canada using a nationally representative survey

In April 2020, the first-ever nationally representative survey in Canada polled 4,240 adults age 19 18 years and older about their COVID experience in March, early in the epidemic. We examined 20 determinants of COVID symptoms, defined as fever plus difficulty breathing/shortness of 21 breath, dry cough so severe that it disrupts sleep, and/or loss of sense of smell; and testing for 22 SARS-CoV-2 by respondents and/or household members. About 8% of Canadians reported that 23 they and/or one or more household members experienced COVID symptoms. Symptoms were 24 more common in younger than older adults, and among visible minorities. Overall, only 3% of 25 respondents and/or household members reported testing for SARS-CoV-2. Being tested was 26 associated with having COVID symptoms, Indigenous identity, and living in Quebec. Periodic 27 nationally representative surveys—including high-risk older populations—of symptoms, as well 28 as SARS-CoV-2 antibodies, are required in many countries to understand the pandemic and 29 prepare for the future.


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The pandemic of SARS-CoV-2 infection causing coronavirus disease-2019 (COVID-19, hereafter 32 "COVID") has affected Canada and many other high-income countries (Eggertson and Wolfville,33 2020). In these settings where reliable data can be gathered, a combination of population- 34 based surveys (including surveys and testing), hospitalizations, and mortality data can produce 35 an accurate profile of the impact of the epidemic. 36 We report on the results of the first nationally-representative poll of self-reported COVID 37 symptoms conducted in Canada by the Angus Reid Forum in early April 2020 covering 38 symptoms reported mostly in March 2020, prior to the peak month of cases in April. Our goal 39 was to understand the distribution and determinants of Canadians reporting possible COVID 40 symptoms. We also sought to understand who underwent testing for SARS-CoV-2 using the 41 current standard (PCR-based) test. We discuss these findings in the context of the age 42 distribution of COVID hospitalizations and deaths, and a planned survey of antibodies to SARS- 43 CoV-2 in a random sample of Canadians. 44

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To determine the representativeness of the respondents, we compared their socio-46 demographic characteristics to those of the Canadian population in 2019 (Table 1). Overall, the 47 survey respondents were broadly representative of Canadian society in terms of gender, age,  . CC-BY-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) The copyright holder for this preprint this version posted June 2, 2020. ; https://doi.org/10.1101/2020.05.29.20109090 doi: medRxiv preprint Of the 4,240 respondents, 334 (7.9% after applying survey weights) reported COVID symptoms, 57 defined as the respondent reporting himself/herself and/or at least one of the household 58 members experiencing a combination of fever (with or without hallucinations) and any of i) 59 difficulty breathing/shortness of breath or ii) dry cough so severe that it disrupts sleep or iii) a 60 loss of a sense of smell. Of these, 210 (5.0%) reported COVID symptoms only in themselves. The 61 adjusted odds ratio (OR) of the respondent having symptoms when at least one of the 62 household members reported symptoms was 1.45 (95% CI 1.41-1.49); the OR was similar for at 63 least one household member having symptoms if the respondent reported symptoms. In terms 64 of testing for SARS-CoV-2, 126 (or 3.0%) reported some household testing or being scheduled 65 for testing, and only 68 (or 1.6%) reported that they have been or are scheduled for testing. 66 Details of the variation in COVID symptoms and SARS-CoV-2 testing in this sample across 67 provinces have already been published (Angus Reid Institute, 2020). 68  Table 3 shows the adjusted odds ratios of respondents or a member of the household being 86 tested or scheduled for SARS-CoV-2 testing. The strongest determinant of testing was having 87 COVID symptoms among members of the household, of whom about 16.5% were tested, 88 compared to 2.1% among those without COVID symptoms among household members 89 (OR=6.63, 4.46-9.79). Testing rates fell with age, but not significantly so. Testing rates were 90 2.7% in English and other European ethnicity, and higher in indigenous people (7.2%; OR=2.07; 91 1.13-3.64). However, the ORs fell notably (from 2.94 to 2.07) after adjustment for co-variates, 92 suggesting residual confounding (data not shown). Testing rates in Quebec were roughly double 93 . CC-BY-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

(which was not certified by peer review)
The copyright holder for this preprint this version posted June 2, 2020. ; https://doi.org/10.1101/2020.05.29.20109090 doi: medRxiv preprint those in Ontario, the reference province (OR=2.41; 1.49-3.96). Findings were similar among 94 those who reported having been tested or being scheduled to be tested (data not shown).

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. CC-BY-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

(which was not certified by peer review)
The copyright holder for this preprint this version posted June 2, 2020. ; https://doi.org/10.1101/2020.05.29.20109090 doi: medRxiv preprint . CC-BY-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

(which was not certified by peer review)
The copyright holder for this preprint this version posted June 2, 2020. ; https://doi.org/10.1101/2020.05.29.20109090 doi: medRxiv preprint . CC-BY-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

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A nationally representative survey of Canadians finds that about 8% of adults report that they 97 or someone in their household reported symptoms suggestive of COVID in March 2020. Being a 98 visible minority was associated with higher self-reported COVID symptoms. Self-reported 99 symptoms were notably less common at older ages than in younger adults. Only 3% of 100 Canadian adults reported that they or someone in the household had been tested for SARS-101 CoV-2. The main determinants of being tested were the presence of COVID symptoms, being of 102 Indigenous identity, and living in Quebec. Testing rates were somewhat lower in older adults. 103 There are surprisingly few nationally representative studies, and despite some limitations, this 104 study represents the first to document self-reported symptoms in a reasonably representative  is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

(which was not certified by peer review)
The copyright holder for this preprint this version posted June 2, 2020. ; https://doi.org/10.1101/2020.05.29.20109090 doi: medRxiv preprint In the UK, pilot results from the COVID-19 Infection Survey being carried out by the Office for 131 National Statistics found that 0.25% of the community population in England above the age of Self-reported symptoms are, by their nature, subject to limitations and misclassification. 163 However, the trends over time, even with misclassification, are useful for understanding trends 164 in the actual underlying prevalence of infection. This is because the "noise" of COVID symptoms 165 should change little from one survey to the next, and provided there is large "signal" due to the 166 . CC-BY-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

(which was not certified by peer review)
The copyright holder for this preprint this version posted June 2, 2020.  193 We also used logistic regression analysis to identify determinants of testing, which included the 194 above explanatory variables and also COVID symptoms in the respondent or a family member. 195 Respondents who did not report on any of the explanatory variables were excluded from these 196 analyses. Discrepancies in or between totals are due to rounding. We applied to prevalences 197 the survey weights, which are described earlier (Angus Reid Institute, 2020). We used RStudio 198 Version 1.1.453 for analyses. 199 Ethics approval 200 . CC-BY-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) The copyright holder for this preprint this version posted June 2, 2020. . CC-BY-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) The copyright holder for this preprint this version posted June 2, 2020. ; https://doi.org/10.1101/2020.05.29.20109090 doi: medRxiv preprint