Table 7.
Penalized logistic regression model results for COVID-19 infection and handwashing, coughing habits, social distancing, and mask wearing.a
| Variables | Infected (model 4; n=5120), ORb (95% CI) | Infected (model 5; n=4154), OR (95% CI) | Infected (model 5; N=8,158), OR (95% CI) | |
| Age groups (years), reference: 18-39 years | ||||
|
|
40-59 | 1.07 (0.47-2.42) | 1.17 (0.49-2.81) | 0.95 (0.50-1.81) |
|
|
≥60 | 3.16 (0.82-12.11) | 3.79 (0.96-14.94) | 1.68 (0.50-5.71) |
| Sex (female vs male) | 0.65 (0.29-1.49) | 0.69 (0.29-1.66) | 0.73 (0.38-1.42) | |
| Living in city (urban vs rural) | 0.85 (0.37-1.95) | 0.75 (0.32-1.77) | 0.89 (0.47-1.68) | |
| Education, reference: primary school | ||||
|
|
High school | 0.09 (0.03-0.30)*** | 0.11 (0.03-0.43)** | 0.12 (0.05-0.31)*** |
|
|
Professional college | 0.09 (0.03-0.34)*** | 0.11 (0.03-0.47)** | 0.10 (0.03-0.29)*** |
|
|
University/postgraduate | 0.08 (0.02-0.33)*** | 0.10 (0.02-0.47)** | 0.15 (0.05-0.46)*** |
| Occupation, reference: health professionals | ||||
|
|
Government payee | 1.74 (0.60-5.06) | 1.59 (0.52-4.85) | 1.57 (0.65-3.81) |
|
|
Factory workers/managers | 1.97 (0.56-6.89) | 1.80 (0.49-6.55) | 1.95 (0.71-5.33) |
|
|
Farmers | 1.35 (0.25-7.27) | 0.76 (0.12-4.97) | 1.08 (0.26-4.43) |
|
|
Students | 1.00 (0.19-5.36) | 0.69 (0.12-4.03) | 1.18 (0.31-4.43) |
|
|
Others | 2.02 (0.49-8.27) | 2.17 (0.52-9.04) | 1.72 (0.54-5.51) |
| Family monthly income (¥), reference: ¥0-¥1000 | ||||
|
|
1001-2000 | 0.42 (0.11-1.57) | 0.58 (0.14-2.38) | 0.62 (0.23-1.72) |
|
|
2001-4000 | 0.77 (0.26-2.28) | 0.90 (0.28-2.92) | 0.73 (0.30-1.78) |
|
|
4001-6000 | 0.47 (0.14-1.52) | 0.64 (0.18-2.25) | 0.63 (0.25-1.58) |
|
|
6001-8000 | 0.56 (0.13-2.37) | 0.73 (0.17-3.25) | 0.50 (0.15-1.68) |
|
|
8001-10,000 | 0.31 (0.06-1.49) | 0.24 (0.03-1.62) | 0.20 (0.05-0.88)* |
|
|
10,001-20,000 | 0.43 (0.10-1.87) | 0.53 (0.11-2.49) | 0.62 (0.19-2.03) |
|
|
20,001-4,000,000 | 0.24 (0.02-2.61) | 0.21 (0.01-3.85) | 0.60 (0.14-2.64) |
|
|
Not sure/unanswered | 0.11 (0.00-2.75) | 0.26 (0.01-4.97) | 0.13 (0.01-2.36) |
| Smoked during the last month (no vs yes) | 0.67 (0.29-1.58) | 0.65 (0.27-1.57) | 0.40 (0.20-0.80)** | |
| Drank alcohol during the last month, reference: yes | ||||
|
|
Gave up | 1.29 (0.43-3.87) | 1.34 (0.43-4.20) | 2.00 (0.78-5.10) |
|
|
Do not drink | 0.48 (0.20-1.13) | 0.47 (0.19-1.15) | 0.85 (0.40-1.80) |
| BMI, reference: underweight | ||||
|
|
Normal | 0.56 (0.25-1.25) | 0.57 (0.24-1.33) | 0.79 (0.40-1.57) |
|
|
Overweight | 0.26 (0.07-0.90)* | 0.28 (0.08-0.99)* | 0.48 (0.19-1.25) |
|
|
Obese | 0.31 (0.02-5.81) | 0.38 (0.02-7.45) | 0.88 (0.16-4.97) |
|
|
Not available | 1.25 (0.46-3.44) | 1.17 (0.40-3.46) | 1.13 (0.45-2.82) |
| Currently living with a partner, reference: yes | ||||
|
|
No | 1.62 (0.69-3.82) | 1.28 (0.50-3.26) | 1.38 (0.70-2.69) |
|
|
I don’t have a partner | 0.98 (0.30-3.20) | 1.19 (0.36-3.91) | 0.53 (0.20-1.41) |
| Family member who is a health professional (yes vs no) | 0.51 (0.22-1.19) | 0.61 (0.25-1.48) | 0.50 (0.24-1.01) | |
| Living in an area with community infection, reference: Hubei Province | ||||
|
|
Outside Hubei Province with ≥100 cases | 0.24 (0.06-0.95)* | 0.25 (0.06-1.09) | 0.45 (0.13-1.51) |
|
|
Other | 0.68 (0.19-2.50) | 0.74 (0.20-2.81) | 0.78 (0.25-2.47) |
| Family member who is part of the local community efforts against COVID-19 (no vs yes) | 0.51 (0.24-1.09) | 0.46 (0.21-1.04) | 0.74 (0.40-1.37) | |
| Handwashing (no vs yes) | N/Ac | 1.82 (0.40-8.32) | N/A | |
| Proper coughing habit (no vs yes) | N/A | 1.88 (0.60-5.94) | N/A | |
| Social distancing (no vs yes) | N/A | 1.07 (0.46-2.46) | N/A | |
| Mask wearing (no vs yes) | 11.03 (4.53-26.84)*** | 7.20 (2.24-23.11)*** | N/A | |
| Constant | 2.04 (0.19-21.47) | 1.64 (0.13-20.42) | 0.78 (0.11-5.62) | |
| AUROCd | 0.825 | 0.823 | 0.748 | |
aModels 1-5 are models adjusting for social demographic variables plus handwashing, coughing habits, social distancing, mask wearing, and all four nonpharmaceutical interventions together, respectively; model 6 is adjusting for social demographic variables only. For each model, the convergency of penalized maximum likelihood function was monitored, and coefficients and their 95% CIs were examined. Each model converged normally in a short time and no irregularity of coefficients and standard errors was identified.
bOR: odds ratio.
cN/A: not applicable.
dAUROC: area under the receiver operating characteristic curve.
*P<.05, **P<.01, ***P<.001