Table 1.
Baseline characteristics of the study population (April–November 2021), stratified by case status (test-positive cases and test-negative controls) and outcome of interest.
| Test-negative controls | Test-positives cases |
||||
|---|---|---|---|---|---|
| Symptomatic infection | Hospitalization | Severe Covid | Death | ||
| Sociodemographicinformation | |||||
| Males, n/N (%) | 12,540/17,014 (73.7) | 9765/12,212 (80.0) | 5356/6287 (85.2) | 3678/4238 (86.8) | 3649/4205 (86.8) |
| Age (median [IQR]) | 70 [65, 76] | 70 [66, 76] | 72 [67, 79] | 73 [68, 79] | 73 [68, 79] |
| Geographical locationa, n/N (%) | |||||
| Centre | 6176/17,014 (36.3) | 3711/12,212 (30.4) | 1723/6287 (27.4) | 1133/4238 (26.7) | 1120/4205 (26.6) |
| West-Centre | 3516/17,014 (20.7) | 2474/12,212 (20.3) | 1416/6287 (22.5) | 944/4238 (22.3) | 940/4205 (22.4) |
| North | 5006/17,014 (29.4) | 3464/12,212 (28.4) | 1958/6287 (31.1) | 1280/4238 (30.2) | 1270/4205 (30.2) |
| South-Southeast | 2316/17,014 (13.6) | 2563/12,212 (21.0) | 1190/6287 (18.9) | 881/4238 (20.8) | 875/4205 (20.8) |
| Monthly pension, MXN (median [IQR]) | 3502 [3,020, 5512] | 3459 [3,011, 5620] | 3317 [3,011, 5349] | 3317 [3,011, 5287] | 3317 [3,011, 5281] |
| Medicalhistory | |||||
| CCI (median [IQR]) | 3 [2, 4] | 3 [2, 4] | 3 [3, 4] | 3 [3, 4] | 3 [3, 4] |
| Diabetes, n/N (%) | 4891/17,014 (28.7) | 3946/12,212 (32.3) | 2456/6287 (39.1) | 1654/4238 (39.0) | 1639/4205 (39.0) |
| NA | 78/17,014 (0.5) | 27/12,212 (0.2) | 7/6287 (0.1) | 3/4238 (0.1) | 3/4205 (0.1) |
| Obesity, n/N (%) | 1731/1,7014 (10.2) | 1434/12,212 (11.7) | 824/6287 (13.1) | 587/4238 (13.9) | 580/4205 (13.8) |
| NA | 78/17,014 (0.5) | 26/12,212 (0.2) | 6/6287 (0.1) | 2/4238 (0.0) | 2/4205 (0.0) |
| Hypertension, n/N (%) | 7212/17,014 (42.4) | 5531/12,212 (45.3) | 3198/6287 (50.9) | 2169/4238 (51.2) | 2149/4205 (51.1) |
| NA | 78/17,014 (0.5) | 28/12,212 (0.2) | 8/6287 (0.1) | 4/4238 (0.1) | 4/4205 (0.1) |
| COPD, n/N (%) | 1207/17,014 (7.1) | 548/12,212 (4.5) | 377/6287 (6.0) | 240/4238 (5.7) | 238/4205 (5.7) |
| NA | 78/17,014 (0.5) | 29/12,212 (0.2) | 8/6287 (0.1) | 5/4238 (0.1) | 5/4205 (0.1) |
| Asthma, n/N (%) | 326/17,014 (1.9) | 165/12,212 (1.4) | 82/6287 (1.3) | 56/4238 (1.3) | 56/4205 (1.3) |
| NA | 78/17,014 (0.5) | 29/12,212 (0.2) | 8/6287 (0.1) | 5/4238 (0.1) | 5/4205 (0.1) |
| Ever smoking, n/N (%) | 1695/17,014 (10.0) | 992/12,212 (8.1) | 642/6287 (10.2) | 405/4238 (9.6) | 399/4205 (9.5) |
| NA | 78/17,014 (0.5) | 30/12,212 (0.2) | 9/6287 (0.1) | 5/4238 (0.1) | 5/4205 (0.1) |
| Cancer, n/N (%) | 267/17,014 (1.6) | 128/12,212 (1.0) | 96/6287 (1.5) | 67/4238 (1.6) | 67/4205 (1.6) |
| NA | 78/17,014 (0.5) | 29/12,212 (0.2) | 8/6287 (0.1) | 5/4238 (0.1) | 5/4205 (0.1) |
| Past COVID-19, n/N (%) | 125/17,014 (0.7) | 4/12,212 (0.0) | 0/6287 (0.0) | 0/4238 (0.0) | 0/4205 (0.0) |
| Episode-relatedvariables | |||||
| Epi-week (median [IQR]) | 35 [29, 41] | 34 [31, 38] | 34 [31, 38] | 34 [31, 38] | 34 [31, 38] |
| NAAT (positives), n/N (%) | 0/17,014 (0.0) | 4466/12,212 (36.6) | 3851/6287 (61.3) | 2477/4238 (58.4) | 2456/4205 (58.4) |
| NA | 12,714/17,014 (74.7) | 7623/12,212 (62.4) | 2327/6287 (37.0) | 1712/4238 (40.4) | 1701/4205 (40.5) |
| RADT (positives), n/N (%) | 0/17,014 (0.0) | 9772/12,212 (80.0) | 4230/6287 (67.3) | 2988/4238 (70.5) | 2966/4205 (70.5) |
| NA | 1119/17,014 (6.6) | 1255/12,212 (10.3) | 1008/6287 (16.0) | 686/4238 (16.2) | 682/4205 (16.2) |
| Vaccinated, n/N (%) | 14,349/17,014 (84.3) | 8947/12,212 (73.3) | 3818/6287 (60.7) | 2383/4238 (56.2) | 2359/4205 (56.1) |
| Days vaccinated (median [IQR]) | 117 [75, 160] | 113 [86, 145] | 116 [90, 149] | 116 [91, 148] | 116 [91, 148] |
| Type of vaccine received, n/N (%) | |||||
| AstraZeneca–AZD1222 | 3846/17,014 (22.6) | 2383/12,212 (19.5) | 996/6287 (15.8) | 630/4238 (14.9) | 623/4205 (14.8) |
| CanSino–Ad5-nCoV | 727/17,014 (4.3) | 774/12,212 (6.3) | 391/6287 (6.2) | 263/4238 (6.2) | 262/4205 (6.2) |
| Pfizer - BNT162b2 | 5184/17,014 (30.5) | 2208/12,212 (18.1) | 878/6287 (14.0) | 491/4238 (11.6) | 483/4205 (11.5) |
| Sinovac–CoronaVac | 3437/17,014 (20.2) | 3103/12,212 (25.4) | 1393/6287 (22.2) | 923/4238 (21.8) | 916/4205 (21.8) |
| Sputnik V–Gam-COVID-Vac | 1155/17,014 (6.8) | 479/12,212 (3.9) | 160/6287 (2.5) | 76/4238 (1.8) | 75/4205 (1.8) |
| Unvaccinated | 2665/17,014 (15.7) | 3265/12,212 (26.7) | 2469/6287 (39.3) | 1855/4238 (43.8) | 1846/4205 (43.9) |
Abbreviations: CCI, Charlson comorbidity index; COPD, Chronic Obstructive Pulmonary Disease; Epi-week, epidemiological week; MXN, Mexican pesos; IQR, interquartile range; NA, not available; NAAT, Nucleic Acid Amplification Test; RADT, Rapid Antigen Diagnostic Test.
a
For definitions, please refer to Supplementary Table S1.