Sociodemographic characteristics and clinical features of confirmed COVID-19 cases during the two waves in Nigeria
| Variable | Wave 1 (n=66 237) | Wave 2 (n=91 664) | P value |
| Sociodemographic characteristics | |||
| Mean (SD) age, years | (n=62 915) | (n=88 435) | 0.2178* |
| 33.57 (15.28) | 37.67 (16.30) | ||
| Age group, years | <0.001† | ||
| 0–4 | 886 (1.34) | 1424 (1.55) | |
| 5–13 | 2395 (3.62) | 3560 (3.88) | |
| 14–20 | 3987 (6.02) | 6638 (7.24) | |
| 21–30 | 13 597 (20.53) | 20 184 (22.02) | |
| 31–40 | 17 691 (26.71) | 21 689 (23.67) | |
| 41–50 | 12 232 (18.47) | 16 121 (17.59) | |
| 51–60 | 7596 (11.47) | 10 870 (11.86) | |
| 61–70 | 3064 (4.63) | 5091 (5.56) | |
| 71–80 | 1116 (1.68) | 2132 (2.33) | |
| >80 | 351 (0.53) | 726 (0.79) | |
| Missing | 3322 (5.02) | 3229 (3.50) | |
| Sex | <0.001† | ||
| Female | 23 609 (35.64) | 38 403 (41.90) | |
| Male | 41 434 (62.55) | 52 754 (57.56) | |
| Missing | 1194 (1.80) | 487 (0.53) | |
| Residential setting | <0.001† | ||
| Rural | 3825 (5.77) | 5192 (5.67) | |
| Urban | 25 807 (38.96) | 26 510 (28.93) | |
| Missing | 36 605 (55.26) | 59 942 (65.41) | |
| Education completed | <0.001† | ||
| None | 949 (1.43) | 911 (0.99) | |
| Nursery | 180 (0.27) | 123 (0.13) | |
| Primary | 1201 (1.81) | 1285 (1.40) | |
| Secondary | 5673 (8.56) | 4814 (5.25) | |
| Tertiary | 15 881 (23.98) | 18 449 (20.13) | |
| Alternative (eg, Almajiranci) | 3102 (4.68) | 1948 (2.13) | |
| Missing | 39 251 (59.26) | 64 114 (69.96) | |
| Current occupation | <0.001† | ||
| Pupil/student | 4419 (6.67) | 4829 (5.27) | |
| Housewife/child | 1096 (1.65) | 1373 (1.50) | |
| Trader/business | 2727 (4.12) | 2342 (2.56) | |
| Farmer/miner | 718 (1.08) | 1007 (1.10) | |
| Healthcare worker | 4973 (7.51) | 2648 (2.89) | |
| Animal-related work | 70 (0.11) | 57 (0.06) | |
| Transporter | 142 (0.21) | 48 (0.05) | |
| Religious leader | 127 (0.19) | 99 (0.11) | |
| Traditional leader | 22 (0.03) | 36 (0.04) | |
| Other | 24 294 (36.68) | 48 150 (52.54) | |
| Missing | 27 649 (41.74) | 31 055 (33.89) | |
| Quarantine location | <0.001† | ||
| None | 5464 (8.25) | 8230 (8.98) | |
| Formal institution | 1912 (2.89) | 205 (0.22) | |
| Home | 6116 (9.23) | 3757 (4.10) | |
| Missing | 52 745 (79.63) | 79 452 (86.70) | |
| Travel history | |||
| No | 38 425 (58.01) | 30 008 (32.74) | |
| Yes | 2495 (3.77) | 901 (0.98) | |
| Missing | 25 317 (38.22) | 60 735 (66.27) | |
| Hospitalisation | <0.001† | ||
| No | 31 197 (47.10) | 49 589 (54.11) | |
| Yes | 6885 (10.39) | 1250 (1.36) | |
| Missing | 28 155 (42.51) | 40 805 (44.53) | |
| Symptomatic status | <0.001† | ||
| Asymptomatic | 49 652 (74.96) | 73 038 (79.70) | |
| Symptomatic | 16 585 (25.04) | 18 606 (20.30) | |
*P value for t-test.
†P value for χ2 test.