Table 1.
Baseline Characteristics of Study Participants (N = 326)
| Characteristic | Total No. of Participants (N = 326)a | Index Cases (n = 85) | Household Members (n = 241) | P Value | OR (95% CI) |
|---|---|---|---|---|---|
| Child (<18 y) | 123 (37.7) | 17 (20.0) | 106 (44.0) | <.001 | 0.32 (.18–.57) |
| Adult | 203 (62.3) | 68 (80.0) | 135 (56.0) | <.001 | 3.14 (1.74–5.66) |
| Age, y, median (IQR) | 28.5 (13.0–46.0) | 40.0 (22.0–48.0) | 20.0 (12.0–45.0) | <.001 | 1.03 (1.02–1.05) |
| Age group, y | |||||
| <12 | 59 (18.1) | 1 (1.2) | 58 (24.1) | 1 (ref) | |
| 12–17 | 64 (19.6) | 16 (18.8) | 48 (19.9) | .005 | 19.33 (2.47–151.11) |
| 18–39 | 74 (22.7) | 25 (29.4) | 49 (20.3) | <.001 | 29.59 (3.89–226.36) |
| 40–49 | 78 (23.9) | 25 (29.4) | 53 (22.0) | <.001 | 27.36 (3.58–208.97) |
| 50–65 | 51 (15.6) | 18 (21.2) | 33 (13.7) | <.001 | 31.64 (4.04–247.85) |
| Sex, female | 157 (48.2) | 56 (65.9) | 101 (41.9) | <.001 | 2.68 (1.60–4.49) |
| BMI classb | |||||
| Normal weight | 195 (59.8) | 45 (52.9) | 150 (66.1) | 1 (ref) | |
| Obesity | 23 (7.1) | 10 (11.8) | 13 (5.7) | .038 | 2.56 (1.05–6.24) |
| Overweight | 87 (26.7) | 28 (32.9) | 59 (26.0) | .108 | 1.58 (.90–2.77) |
| Underweight | 7 (2.1) | 2 (2.4) | 5 (2.2) | .736 | 1.33 (.25–7.11) |
| Underlying medical condition | 37 (11.3) | 10 (11.8) | 27 (11.2) | .888 | 1.06 (.49–2.29) |
| Cardiovascular disease | 10 (3.1) | 2 (2.4) | 8 (3.3) | … | |
| Lung disease | 1 (0.3) | 1 (1.2) | 0 (0.0) | … | |
| Immune disorder | 1 (0.3) | 1 (1.2) | 0 (0.0) | … | |
| Diabetes | 3 (0.9) | 1 (1.2) | 2 (0.8) | … | |
| Rheumatic disorder | 2 (0.6) | 1 (1.2) | 1 (0.4) | … | |
| Other | 24 (7.4) | 5 (5.9) | 19 (7.9) | … | |
| Smoking (yes) | 11 (3.4) | 4 (4.7) | 7 (2.9) | .433 | 1.65 (.47–5.79) |
| Nationality (other)c | 4 (1.2) | 2 (2.4) | 2 (0.8) | .298 | 2.86 (.40–20.60) |
| Positive saliva day 1d | 176 (54.0) | 73 (85.9) | 103 (42.7) | <.001 | 13.37 (5.90–30.26) |
| Symptom statuse | |||||
| Severe symptomsf | 2 (0.6) | 1 (1.2) | 1 (0.4) | .052 | 17.29 (.98–306.28) |
| Moderate symptoms | 47 (14.4) | 22 (25.9) | 25 (10.4) | <.001 | 15.21 (5.86–39.46) |
| Mild symptoms | 149 (45.7) | 55 (64.7) | 94 (39.0) | <.001 | 10.11 (4.40–23.23) |
| Asymptomatic | 128 (39.2) | 7 (8.2) | 121 (50.2) | 1 (ref) |
Data are presented as No. (%) unless otherwise indicated.
Abbreviations: BMI, body mass index; CI, confidence interval; IQR, interquartile range; OR, odds ratio.
Some numbers might not add up to 326 due to missing values.
BMI categories for index cases and household members 2 to <18 years of age were defined as BMI z-score < –2, underweight; –2 to 1, normal weight; 1–2, overweight; >2, obesity (source: Centers for Disease Control and Prevention, https://www.cdc.gov/growthcharts/zscore.htm, accessed 28 September 2021). BMI categories for index cases and household members ≥18 years of age were defined as <18.5 kg/m2, underweight; 18.5–24.9 kg/m2, normal weight; 25.0–29.9 kg/m2, overweight; ≥30.0 kg/m2, obesity.
Other than Dutch.
Saliva at day 1 available for 315 participants.
Maximum over 10 time points.
Hospital admission due to coronavirus-related symptoms.