Table 1 Baseline characteristics of participants included in seropositivity analysis
|  | Characteristics (N = 11,130) |
|---|---|
Sociodemographic, occupational and lifestyle factors | |
 Age (years) | 62.3 (52.9–68.7) |
   < 30 | 323 (2.9%) |
  30 to < 40 | 651 (5.8%) |
  40 to < 50 | 1246 (11.2%) |
  50 to < 60 | 2545 (22.9%) |
  60 to < 70 | 4098 (36.8%) |
  ≥ 70 | 2267 (20.4%) |
 Sex | |
  Female | 7806 (70.1%) |
  Male | 3324 (29.9%) |
 Ethnicity | |
  Black, African, Caribbean or Black British | 49 (0.4%) |
  South Asiana | 145 (1.3%) |
  Mixed, multiple or other ethnic groups | 285 (2.6%) |
  White | 10,651 (95.7%) |
 Country of residence | |
  England | 9835/11,129 (88.4%) |
  Northern Ireland | 188/11,129 (1.7%) |
  Scotland | 694/11,129 (6.2%) |
  Wales | 412/11,129 (3.7%) |
 Housing | |
  Owns own home | 7059/11,129 (63.4%) |
  Mortgage | 2716/11,129 (24.4%) |
  Privately renting | 654/11,129 (5.9%) |
  Renting from council | 318/11,129 (2.9%) |
  Other | 382/11,129 (3.4%) |
 Number of people per bedroom | |
  ≤ 0.5 | 4382/11,059 (39.6%) |
  > 0.5 to < 1 | 3085/11,059 (27.9%) |
  1 to < 2 | 3355/11,059 (30.3%) |
  ≥ 2 | 237/11,059 (2.1%) |
 Shares home with | |
  Pre-school children (0–4 years) | 362/11,106 (3.3%) |
  Schoolchildren (5–15 years) | 1227/11,101 (11.1%) |
  Working-age adult (16–64 years) | 5748/11,101 (51.8%) |
 Household income sufficient for basic needs | |
  Yes | 10,409/11,129 (93.5%) |
  Mostly | 390/11,129 (3.5%) |
  Sometimes | 80/11,129 (0.7%) |
  No | 250/11,129 (2.2%) |
 Claiming Universal Credit | 275/11,098 (2.5%) |
 IMD decile | 7 (5–9) |
 Occupational status | |
  Employed | 3662 (32.9%) |
  Self-employed | 1048 (9.4%) |
  Retired | 5284 (47.5%) |
  Furloughed | 282 (2.5%) |
  Unemployed | 186 (1.7%) |
  Student | 174 (1.6%) |
  Other | 494 (4.4%) |
 Frontline worker | 1700/11,112 (15.3%) |
  Health or social care | 499/11,112 (4.5%) |
  Other | 1201/11,112 (10.8%) |
 Highest educational level attained | |
  Primary or secondary | 1194/11,123 (10.7%) |
  Higher or further education (A levels or BTEC) | 1600/11,123 (14.4%) |
  College or university | 4961/11,123 (44.6%) |
  Postgraduate degree | 3368/11,123 (30.3%) |
 Tobacco smoking status | |
  Never-smoker | 6281 (56.4%) |
  Ex-smoker | 4325 (38.9%) |
  Current smoker | 524 (4.7%) |
 Regular environmental tobacco smoke exposure | 203/11,128 (1.8%) |
 Vaping status | |
  Never-vaper | 10,463/11,099 (94.3%) |
  Ex-vaper | 339/11,099 (3.1%) |
  Current vaper | 297/11,099 (2.7%) |
 Alcohol (units per week) | |
  None | 2986/11,129 (26.8%) |
  1–7 | 3932/11,129 (35.3%) |
  8–14 | 2249/11,129 (20.2%) |
  ≥ 15 | 1962/11,129 (17.6%) |
 Does any vigorous physical exercise | 7001/11,102 (63.1%) |
  1–3 h per week | 4142/11,102 (37.3%) |
  ≥ 4 h per week | 2859/11,102 (25.8%) |
 Duration of follow-up (days) | 178 (26–419) |
Medical conditions and prescribed medication use | |
 Self-reported general health | |
  Excellent | 2291/11,129 (20.6%) |
  Very good | 4435/11,129 (39.9%) |
  Good | 2939/11,129 (26.4%) |
  Fair | 1147/11,129 (10.3%) |
  Poor | 317/11,129 (2.8%) |
 BMI, kg/m2 | 26.2 (5.3) |
  < 25 | 5424/11,106 (48.8%) |
  25–30 | 3586/11,106 (32.3%) |
  > 30 | 2096/11,106 (18.9%) |
Comorbidities | |
 Arterial diseaseb | 552 (5.0%) |
 Asthma | 1800 (16.2%) |
 Atopyc | 2861 (25.7%) |
 Autoimmune diseased | 965 (8.7%) |
 Cancer | 1036 (9.3%) |
  Past (cured or in remission) | 945 (8.5%) |
  Present (active treatment) | 91 (0.8%) |
 COPD | 213 (1.9%) |
 Diabetes or pre-diabetes | 858 (7.7%) |
  Pre-diabetes | 332/11,118 (3.0%) |
  Type 1 | 80/11,118 (0.7%) |
  Type 2 | 434/11,118 (3.9%) |
 Heart diseasee | 408 (3.7%) |
 Hypertension | 2379 (21.4%) |
 Immunodeficiencyf | 64 (0.6%) |
 Kidney disease | 214 (1.9%) |
 Major neurological conditionsg | 287 (2.6%) |