Table 1. Characteristics of the study population in Hospital Universitario San Ignacio (Retrospective cohort and seroprevalence study).
March 6, 2020 to February 12, 2021.
| Participant Characteristics | n (%)1 |
| Sex (n = 2597) | |
| Female | 1940 (74.7%) |
| Male | 657 (25.3%) |
| Age (years), (n = 2597) | |
| < 35 | 1377 (53.0%) |
| 35–44 | 772 (29.7%) |
| ≥ 45 | 448 (17.3%) |
| Type of occupation (n = 2597) | |
| Direct patient care | 2026 (78.0%) |
| Administrative | 571 (22.0%) |
| Type of direct patient care worker (n = 2026) | |
| Medical specialist | 327 (16.1%) |
| Resident | 242 (11.9%) |
| General physician | 49 (2.4%) |
| Nurse | 326 (16.1%) |
| Nurse assistant | 674 (33.3%) |
| Bacteriologist | 67 (3.3%) |
| Respiratory therapist | 30 (1.5%) |
| Nutritionist | 10 (0.5%) |
| Other | 301 (14.9%) |
| Main Service (n = 2585) | |
| Administrative departments | 373 (14.4%) |
| Emergency room | 392 (15.2%) |
| General wards | 711 (27.5%) |
| ICU2 | 266 (10.3%) |
| Surgical Areas | 285 (11.0%) |
| Ambulatory and diagnostic services | 558 (21.6%) |
| Adequate use of PPE3 (n = 2548) | |
| Yes | 2482 (97.4%) |
| No | 66 (2.6%) |
| Type of respiratory protection (n = 2536) | |
| Cloth mask | 100 (3.9%) |
| Surgical mask | 1006 (39.7%) |
| N-95 respirator | 1430 (56.4%) |
| History of close contact4 (n = 2523) | |
| Yes | 1219 (48.3%) |
| No | 1304 (51.7%) |
| Type of close contact5 (n = 1215) | |
| Outside of the work environment | 289 (23.8%) |
| Work area | 863 (71.0%) |
| HUSI wellness area | 63 (5.2%) |
| Type of work (n = 2548) | |
| Remote work | 304 (11.9%) |
| Non-remote work | 2244 (88.1%) |
| COVID-19 work6 (n = 2546) | |
| Yes | 1342 (52.7%) |
| No | 1204 (47.3%) |
| Shift (n = 2549) | |
| Day shift | 1690 (66.3%) |
| Night shift | 859 (33.7%) |
| Type of transportation7 (n = 2526) | |
| Unshared | 1235 (48.9%) |
| Shared | 1291 (51.1%) |
| Work in more than one institution (n = 2540) | |
| Work at only one institution | 2301 (90.6%) |
| Work at two or more institutions | 239 (9.4%) |
| Smoking in the previous year8 (n = 2516) | |
| Yes | 317 (12.6%) |
| No | 2199 (87.4%) |
| Influenza vaccination in the previous year9 (n = 2482) | |
| Yes | 974 (39.2%) |
| No | 1508 (60.8%) |
| Body Mass Index (kg/m2), (n = 2514) | |
| Low or normal (<25) | 1503 (59.8%) |
| Overweight (25.0–29.9) | 826 (32.9%) |
| Obesity (≥30) | 185 (7.4%) |
| Comorbidities10,11 (n = 2525) | |
| Any comorbidity | 427 (16.9%) |
| Arterial Hypertension | 129 (5.1%) |
| Hypothyroidism | 111 (4.4%) |
| Asthma | 88 (3.5%) |
| Autoimmune Disease | 30 (1.2%) |
| Cancer | 12 (0.5%) |
1Column-based percentages.
2ICU, Intensive Care Unit.
3PPE, personal protective equipment. Complete use of PPE since March 2020.
4HCWs who were less than 6 feet away from a SARS-CoV-2-infected person (laboratory-confirmed or a clinical diagnosis) for a total of 15 min without PPE, at any time since March 2020.
5This category only applies to HCWs with close contact history.
6HCWs who worked in the COVID area any time since March 2020.
7Shared transportation was defined as the use of any public or collective transport.
8History of smoking in the previous year.
9History of influenza vaccination in the previous year.
10Self-reported pre-existing medical condition.
11These categories are not mutually exclusive. HCW, healthcare worker.