Table 1

Demographics, comorbidities and behavioural risk factors of participants in the COVID-19 Citizen Science Study assessed at the time of enrolment, divided by participants who later tested positive for COVID-19 during the study period and participants who did not

Participants with incident SARS-CoV-2 (n=112)Participants without incident SARS-CoV-2 (n=28 463)P value
Age, median (IQR)46.0 (37.0–55.5)44.0 (36.0–55.0)0.84
Age category, n (%)0.71
 18–2912 (10.7)2594 (9.2)
 30–3926 (23.2)7832 (27.7)
 40–4931 (27.7)7121 (25.2)
 50–5927 (24.1)6041 (21.3)
 60+16 (14.3)4711 (16.6)
Female biological sex, n (%)71 (65.1)18 908 (67.7)0.79
Race/ethnicity, n (%)0.25
 White94 (86.2)23 814 (85.2)
 Black2 (1.8)229 (0.8)
 Hispanic (any race)9 (8.3)1902 (6.8)
 Asian or Pacific Islander1 (0.9)1384 (5.0)
 Other (including multiracial)3 (2.8)618 (2.2)
Highest level of education, median, n (%)<0.001
 Less than high school1 (0.9)101 (0.4)
 High school graduate8 (7.3)882 (3.2)
 Some college24 (22.0)4091 (14.7)
 College graduate40 (36.7)9891 (35.4)
 Postgraduate33 (30.3)12 690 (45.5)
 Other3 (2.8)247 (0.9)
MacArthur Subjective Social Status Ladder, mean (SD)6.6 (1.5)6.9 (1.6)0.054
Working in healthcare, n (%)31 (27.7)5719 (20.1)0.046
Medical comorbidities, n (%)
 Atrial fibrillation2 (1.8)835 (3.0)0.47
 Anaemia8 (7.2)2957 (10.5)0.26
 AnaemiaAsthma9 (8.0)2815 (9.9)0.5
 Coronary artery disease2 (1.8)693 (2.4)0.65
 Cancer5 (4.5)908 (3.2)0.45
 Congestive heart failure1 (0.9)174 (0.6)0.71
 COPD2 (1.8)444 (1.6)0.84
 Diabetes8 (7.1)1163 (4.1)0.11
 Hypertension31 (27.7)5675 (20.1)0.045
 HIV3 (2.7)108 (0.4)<0.001
 Other immunodeficiency4 (3.6)542 (1.9)0.21
 History of heart attack2 (1.8)283 (1.0)0.4
 Sleep apnoea13 (11.7)3019 (10.8)0.75
 History of stroke2 (1.8)355 (1.3)0.6
Alcohol use0.1
 None26 (24.8)6541 (25.7)
 >0–7 drinks per week60 (57.1)13 362 (52.6)
 >7–14 drinks per week18 (17.1)3764 (14.8)
 >14 drinks per week1 (1.0)1743 (6.9)
Smoking
 Cigarette use in the last 30 days8 (7.2)1421 (5.0)0.29
 E-cigarette use in the last 30 days5 (4.5)723 (2.6)0.19
 Marijuana use in the last 30 days10 (9.0)2650 (9.5)0.87
Sleep duration, median (IQR)7.0 (6.0–8.0)7.0 (6.0–8.0)
Living with children at home, n (%)34 (30.4)8926 (31.6)0.78
Living with pets at home, n (%)73 (65.8)18 442 (64.9)0.86
Use of face masks, n (%)0.29
 ‘Never’10 (9.3)1650 (6.0)
 ‘Sometimes’17 (15.7)3359 (12.2)
 ‘Most times’75 (69.4)20 591 (74.8)
 ‘Always’6 (5.6)1910 (6.9)
Handwashing frequency, n (%)0.32
 <1 time/day0 (0)55 (0.2)
 ~1 time/day1 (0.9)341 (1.2)
 2–4 times/day16 (14.3)4699 (16.5)
 5–10 times/day47 (42.0)13 866 (48.7)
 >10 times/day48 (42.9)9502 (33.4)
Exercise frequency, n (%)<0.001
 Never/rarely5 (4.5)1591 (5.6)
 <1 time/month16 (14.3)2369 (8.3)
 <1 time/week23 (20.5)3678 (12.9)
 Approximately weekly12 (10.7)3668 (12.9)
 2–4 days/week30 (26.8)8956 (31.5)
 >4 days/week23 (20.5)8107 (28.5)
Number of contacts in the past 24 hours, mean (SD)3.8 (6.2)3.1 (7.3)0.36
Number of events with 10 or more people in the past week, mean (SD)3.8 (14.0)1.9 (9.8)0.035
Number of gym visits in the past week, mean (SD)0.4 (3.4)0.9 (6.6)0.5
Number of visits to movie theatres in the past week, mean (SD)0.1 (0.9)0.1 (1.6)0.81
Number of visits to restaurants in the past week, mean (SD)3.4 (9.3)2.2 (7.7)0.095
  • COPD, chronic obstructive pulmonary disease.