Characteristics of healthcare workers exposed to COVID-19 by severity status*
| Total | Controls | Cases | P value† | ||
| Very mild to mild | Moderate to severe | ||||
| Sample size, N | 2884 | 2316 | 430 | 138 | |
| Gender | |||||
| Women | 794 (27.5%) | 640 (27.6%) | 119 (27.7%) | 35 (25.4%) | 0.10 |
| Men | 2066 (71.6%) | 1656 (71.5%) | 310 (72.1%) | 100 (72.5%) | |
| Other | 2 (0.1%) | 1 (0.04%) | 0 (0.0%) | 1 (0.7%) | |
| Prefer not to say | 22 (0.8%) | 19 (0.8%) | 1 (0.2%) | 2 (1.4%) | |
| Age, years | 48 (10) | 48 (10) | 47.1 (9.5) | 48.3 (9.5) | 0.19 |
| Country | 0.048 | ||||
| USA | 1061 (36.8%) | 901 (38.9%) | 116 (27.0%) | 44 (31.9%) | |
| UK | 327 (11.3%) | 233 (10.1%) | 66 (15.3%) | 28 (20.3%) | |
| Spain | 528 (18.3%) | 382 (16.5%) | 125 (29.1%) | 21 (15.2%) | |
| Italy | 433 (15.0%) | 359 (15.5%) | 54 (12.6%) | 20 (14.5%) | |
| Germany | 279 (9.7%) | 233 (10.1%) | 35 (8.1%) | 11 (8.0%) | |
| France | 256 (8.9%) | 208 (9.0%) | 34 (7.9%) | 14 (10.1%) | |
| Race/ethnicity | |||||
| White | 2218 (77.0%) | 1792 (77.4%) | 334 (77.7%) | 92 (66.7%) | 0.13 |
| Any mixed/multiple ethnic background | 162 (6.0%) | 121 (5.2%) | 28 (6.5%) | 13 (9.4%) | |
| Asian | 336 (12.0%) | 271 (11.7%) | 46 (10.7%) | 19 (13.8%) | |
| African | 48 (2.0%) | 36 (1.6%) | 7 (1.6%) | 5 (3.6%) | |
| Other | 36 (1.0%) | 29 (1.3%) | 5 (1.2%) | 2 (1.4%) | |
| Prefer not to say | 84 (3.0%) | 67 (2.9%) | 10 (2.3%) | 7 (5.1%) | |
| Job classification | |||||
| Physician | 2735 (94.8%) | 2187 (94.4%) | 412 (95.8%) | 136 (98.6%) | 0.13 |
| Nurse/NP/PA | 149 (5.2%) | 129 (5.6%) | 18 (4.2%) | 2 (1.4%) | |
| Physician specialty | |||||
| Other | 12 (0.4%) | 10 (0.4%) | 1 (0.2%) | 1 (0.7%) | 0.27 |
| Allergy and Immunology | 29 (1.0%) | 25 (1.1%) | 4 (0.9%) | 0 (0.0%) | |
| Cardiology | 281 (9.7%) | 227 (9.8%) | 38 (8.8%) | 16 (11.6%) | |
| Critical care | 282 (9.8%) | 230 (9.9%) | 42 (9.8%) | 10 (7.2%) | |
| Emergency medicine | 603 (20.9%) | 512 (22.1%) | 70 (16.3%) | 21 (15.2%) | |
| Endocrinology, diabetes, and metabolism | 98 (3.4%) | 74 (3.2%) | 15 (3.5%) | 9 (6.5%) | |
| Gastroenterology | 94 (3.3%) | 77 (3.3%) | 12 (2.8%) | 5 (3.6%) | |
| Haematology | 112 (3.9%) | 85 (3.7%) | 18 (4.2%) | 9 (6.5%) | |
| Infectious disease | 100 (3.5%) | 82 (3.5%) | 14 (3.3%) | 4 (2.9%) | |
| Internal medicine | 433 (15.0%) | 322 (13.9%) | 84 (19.5%) | 27 (19.6%) | |
| Nephrology | 53 (1.8%) | 38 (1.6%) | 15 (3.5%) | 0 (0.0%) | |
| Neurology | 107 (3.7%) | 82 (3.5%) | 21 (4.9%) | 4 (2.9%) | |
| Pulmonology | 430 (14.9%) | 354 (15.3%) | 53 (12.3%) | 23 (16.7%) | |
| Rheumatology | 101 (3.5%) | 69 (3.0%) | 25 (5.8%) | 7 (5.1%) | |
| Nurse/NP/PA practice setting | |||||
| Emergency room | 24 (16.1%) | 22 (17.1%) | 1 (6.0%) | 1 (50.0%) | 0.12 |
| Intensive care unit | 50 (33.6%) | 45 (34.9%) | 5 (28.0%) | 0 (0.0%) | |
| Other hospital-based department | 75 (50.3%) | 62 (48.1%) | 12 (67.0%) | 1 (50.0%) | |
| COVID-19 test (PCR or antibody) | |||||
| No – I did not get a test | 748 (25.9%) | 695 (30.0%) | 38 (8.8%) | 15 (10.9%) | <0.001 |
| No – I did not have access to the test | 101 (3.5%) | 69 (2.9%) | 21 (4.9%) | 11 (8.0%) | |
| Yes – I tested negative | 1737 (60.2%) | 1552 (67.0%) | 160 (37.2%) | 25 (18.1%) | |
| Yes – I tested positive | 298 (10.3%) | 0 (0%) | 211 (49.1%) | 87 (63.0%) | |
| Presence of pre-existing medical conditions | 1264 (44.0%) | 1002 (43.0%) | 196 (45.6%) | 66 (47.8%) | 0.65 |
| Smoking status | 0.64 | ||||
| Never smoker | 2323 (80.5%) | 1865 (80.5%) | 344 (80.0%) | 114 (82.6%) | |
| Former smoker | 427 (14.8%) | 341 (14.7%) | 66 (15.3%) | 20 (14.5%) | |
| Current smoker | 134 (4.6%) | 110 (4.7%) | 20 (4.7%) | 4 (2.9%) | |
| Body mass index (kg/m2 ) | 25.0 (4.3) | 24.9 (4.2) | 24.9 (4.8) | 25.2 (4.8) | 0.57 |
| Self-reported diets‡ | |||||
| Plant-based diets§ | 254 (8.8%) | 213 (9.2%) | 37 (8.6%) | 4 (2.9%) | 0.02 |
| Plant-based diets or pescatarian diets¶ | 294 (10.2%) | 248 (10.7%) | 40 (9.3%) | 6 (4.3%) | 0.06 |
| Low carbohydrate, high protein diets** | 483 (16.7%) | 392 (16.9%) | 61 (14.2%) | 30 (21.7%) | 0.04 |
*Values are n (%) for categorical variables and mean (SD) for continuous variables. Cases are defined as individuals with self-reported COVID-19-like illness (fever, coughing, fatigue, loss of taste or smell) or a positive PCR or antibody test.
†P value compared moderate-to-severe severity versus very mild to mild severity among cases.
‡Participants were asked to report if they followed any type of specific diet over the past 12 months before the COVID-19 pandemic.
§Participants self-reported that they followed whole foods, plant-based diets or vegetarian diets.
¶Participants self-reported that they followed whole foods, plant-based diets or vegetarian diets or pescatarian diets.
**Participants self-reported that they followed low carbohydrate diets or high protein diets.
NP, nurse practitioner; PA, physician assistant.