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. 2021 Feb 8;23(2):e23400. doi: 10.2196/23400

Table 2.

Participants’ demographic characteristics and self-assessment results for their risk of contracting COVID-19, stratified by demographic variables (N=24,547).

Demographic characteristics Number of participants, n (%) Opinion of infection (% chance), mean (SD) t test (df) or F test (df) P value
Gender 10.99a (24,464.28) <.001

Female 12465 (50.8) 34.70 (21.44)


Male 12082 (49.2) 31.65 (22.01)

Number of COVID-19 cases in a participant’s state of current residence 5.83b (5) <.001

0-1000 606 (2.5) 33.07 (22.39)


1001-5000 5326 (21.7) 33.91 (21.87)


5001-10,000 3638 (14.8) 32.71 (21.46)


10,001-20,000 6937 (23.3) 32.96 (21.71)


20,001-40,000 6834 (27.8) 32.71 (21.63)


≥40,001 1206 (4.9) 35.80 (22.97)

Age (years) 163.72b (3) <.001

0-20 6100 (24.9) 31.33 (21.00)


20-40 6677 (27.2) 36.59 (22.05)


40-60 6191 (25.2) 35.28 (22.16)


>60 5579 (22.7) 28.89 (20.92)

BMIc 18.68b (3) <.001

Underweight (BMI<18.5 kg/m2) 568 (2.3) 31.55 (21.13)


Normal weight (BMI=18.5-24.9 kg/m2) 7136 (29.1) 32.15 (21.61)


Preobesity (BMI=25-29.9 kg/m2) 7226 (29.4) 32.70 (21.64)


Obesity (BMI≥30 kg/m2) 9617 (39.2) 34.46 (21.98)

Smoking status 10.52b (3) <.001

Never 13919 (56.7) 32.61 (21.53)


Quit 5374 (21.9) 33.42 (21.92)


Vape 2189 (8.9) 34.21 (21.46)


Yes 3065 (12.5) 34.78 (22.72)

Alcohol consumption status 48.22b (2) <.001

Never 6165 (25.1) 30.95 (21.70)


None in last 14 days 5750 (23.4) 33.27 (21.87)


Some in last 14 days 12632 (51.5) 34.27 (21.69)

Nonprescription/recreational drug used 52.52b (2) <.001

Never 11621 (47.3) 31.86 (21.74)


None in last 28 days 6491 (26.4) 34.15 (21.67)


Some in last 28 days 5065 (20.6) 35.33 (21.68)

Underlying medical conditions −10.93a (24,545) <.001

None 14983 (61) 31.99 (21.60)


Have 9564 (39.0) 35.10 (21.92)

aA 2-tailed t test value.

bAn F test value.

cBMI: body mass index; participants had a mean BMI of 29.41 kg/m2 (SD 7.74 kg/m2).

dThe total number of participants in this category does not equal 24,547 due to missing data.