Table 1.
Study participant characteristics
| All participants (N = 1143 children; 1137 mothers) | Participants from Mbekweni (N = 634) | Participants from TC Newman (N = 509) | P‐value | |
|---|---|---|---|---|
| Socio‐demographics | ||||
| Females | 554 (48.5%) | 322 (50.8%) | 232 (45.6%) | 0.080 |
| Race: African | 632 (55.3%) | 626 (98.7%) | 6 (1.2%) | <0.0001 |
| Race: Mixed‐ancestry | 511 (44.7%) | 8 (1.3%) | 503 (98.8%) | ‐ |
| Household income per month (South African Rand [ZAR]) * | ||||
| <R1000 | 420 (36.7%) | 262 (41.3%) | 158 (31.2%) | <0.0001 |
| R1000‐R5000 | 565 (49.5%) | 305 (48.1%) | 260 (51.3%) | ‐ |
| >R5000 | 156 (13.7%) | 67 (10.6%) | 89 (17.6%) | ‐ |
| Education | ||||
| Primary | 86 (7.6%) | 49 (7.7%) | 37 (7.3%) | 0.045 |
| Secondary | 609 (53.2%) | 343 (54.2%) | 266 (52.2%) | ‐ |
| Completed secondary | 375 (32.8%) | 192 (30.0%) | 183 (36.0%) | ‐ |
| Any tertiary | 73 (6.4%) | 50 (7.9%) | 23 (4.5%) | ‐ |
| Socioeconomic status quartile | ||||
| Lowest | 274 (23.9%) | 185 (29.2%) | 89 (17.5%) | < 0.0001 |
| Low‐moderate | 296 (25.9%) | 174 (27.4%) | 122 (24.0%) | ‐ |
| High‐moderate | 290 (25.4%) | 146 (23.0%) | 144 (28.3%) | ‐ |
| Highest quartile | 283 (24.8%) | 129 (20.3%) | 154 (30.2%) | ‐ |
| Maternal or household characteristics | ||||
| Maternal age at delivery | 26.07 (22.29‐31.09) | 27.01 (22.66‐31.96) | 24.99 (21.73‐29.45) | <0.0001 |
| Antenatal maternal smoking | 306 (26.8%) | 39 (6.2%) | 267 (52.5%) | <0.0001 |
| Postnatal household smokers | ||||
| 1 | 396 (34.8%) | 230 (36.5%) | 166 (32.7%) | <0.0001 |
| >2 | 369 (32.4%) | 113 (17.9%) | 256 (50.4%) | ‐ |
| Antenatal Maternal Alcohol use *** | ||||
| Low risk | 886 (89.0%) | 503 (93.2%) | 383 (84.2%) | <0.0001 |
| Moderate risk | 78 (7.8%) | 12 (2.2%) | 66 (14.5%) | ‐ |
| High risk | 31 (3.1%) | 25 (4.6%) | 6 (1.3%) | ‐ |
| Maternal HIV | 248 (21.7%) | 232 (36.6%) | 16 (3.1%) | <0.0001 |
| Family history of asthma | 25 (2.2%) | 6 (0.9%) | 19 (3.7%) | 0.001 |
| Birth characteristics | ||||
| Gestation (weeks) | 39 (38‐40) | 39 (38‐40) | 39 (37‐40) | 0.287 |
| Prematurity (<37 weeks) | 194 (16.9%) | 110 (17.4%) | 84 (16.4%) | 0.705 |
| Birthweight (kg) | 3.09 (2.71‐3.42) | 3.16 (2.79‐3.46) | 3.00 (2.63‐3.36) | <0.0001 |
| Feeding choice | ||||
| Initiated breastfeeding | 1 047 (91.6%) | 542 (85.5%) | 505 (99.2%) | <0.0001 |
| Exclusive breastfeeding months | 1.00 (0.45‐3.00) | 0.92 (0.00‐2.76) | 1.61 (0.92‐3.00) | <0.0001 |
| Child follow‐up time (months) | 23.98 (17.87 ‐25.00) | 22.55 (16.82‐24.90) | 24.57 (18.07‐25.07) | <0.0001 |
| Vaccinations | ||||
| BCG (Birth) | 1009/1016 (99.3%) | 547/551 (99.3%) | 462/465 (99.4%) | 0.877 |
| DTaP‐IPV‐Hib (6‐10 weeks) | 981/986 (99.5%) | 542/545 (99.4%) | 439/441 (99.5%) | 0.831 |
| DTaP‐IPV‐Hib (10 weeks) | 967/972 (99.5%) | 532/535 (99.4%) | 435/437 (99.5%) | 0.823 |
| DTaP‐IPV‐Hib (14 weeks) | 943/952 (99.2%) | 521/525 (99.4%) | 422/427 (98.8%) | 0.315 |
| DTaP‐IPV‐Hib (18 months) | 536/655 (81.8%) | 323/342 (94.4%) | 213/313 (68.1%) | < 0.0001 |
| PCV13 (6‐10 week) | 983/987 (99.6%) | 543/546 (99.5%) | 440/441 (99.8%) | 0.428 |
| PCV13 (14 week) | 945/952 (99.3%) | 522/525 (99.4%) | 423/427 (99.1%) | 0.512 |
| PCV13 (9 months) | 868/881 (98.5%) | 492/496 (99.2%) | 376/385 (97.7%) | 0.062 |
| Wheeze episodes | ||||
| Total Wheeze episodes a , b , c | 924 | 420 (45.5%) | 504 (54.5%) | ‐ |
| Total maternal reported episodes | 437 | 152 (34.7%) | 285 (65.3%) | ‐ |
| Total LRTIassociated episodes | 0487 | 268 (55.0%) | 219 (45.0%) | ‐ |
| No. of children with wheeze | 479 (41.9%) | 232 (36.6%) | 247 (48.5%) | <0.0001 |
| No. of children with recurrent wheeze | 186 (16.3%) | 78 (12.3%) | 108 (21.2%) | <0.0001 |
HIV, human immunodeficiency virus; BCG, bacillus Calmette‐Guérin vaccine; DTaP‐IPV‐HiB, diphtheria, tetanus, acellular pertussis, polio, and haemophilus influenzae type b; PCV, pneumococcal conjugate vaccine; LRTI, lower respiratory tract infection.
*
Missing data from two participants from TC Newman.
**Missing data for six participants: three from Mbekweni and three from TC Newman.
***
Missing data from one‐hundred and forty‐eight participants: ninety‐four from Mbekweni and fifty‐four from the TC Newman.
a
wheeze episodes over time: 0‐6 months: n = 452; 712 months: N = 229; 13‐18 months: N = 151; 19‐24 months: n = 92.
b
Crude incidence rate: 0.497.
c
Incidence rate over 12‐ month period: 0‐12 months: 0.6998; 13–‐24 months: 0.2839.