Table 4.
Baseline characteristics and BCG-scarification 13 months after neonatal BCG vaccination among the 2118 BCG-vaccinated children in the Danish Calmette Study.
| Determinants | (+) BCG, N = 2118 Numbers of Infants (%) [Missing] |
Data for scars |
Crude |
Adjusted∗ |
||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Number of infants with scar information (2039), (% with information) [Missing] | No scar (182) | Scar prevalence (1857) (%) | Prevalence ratio (95 % CI) N = 2039 | p-value∗∗ | Prevalence ratio (95% CI) N = 1968 | p-value∗∗ | ||||
| External determinants | Study site | Hvidovre hospital | 734 (35) | 688 (94) | 101 | 587 (85) | 1 (ref.) | 1 (ref.) | ||
| Rigshospitalet | 761 (36) | 741 (97) | 36 | 705 (95) | 1.11 (1.08–1.16) | <0.001 | 1.24 (1.18–1.30) | <0.001 | ||
| Kolding hospital | 623 (29) | 610 (98) | 45 | 565 (93) | 1.08 (1.04–1.13) | 1.27 (1.19–1.35) | ||||
| Vaccine batch | 1. "112032A″ | 1195 (56) | 1159 (97) | 81 | 1078 (93) | 1 (ref.) | 1 (ref.) | |||
| 2. "111046B″ | 923 (44) | 880 (95) | 101 | 779 (89) | 0.95 (0.92–0.98) | <0.001 | 0.90 (0.85–0.96) | <0.001 | ||
| Vaccinator Experience (number of children vaccinated) | 0 to 9 | 328 (16) | 310 (95) | 31 | 279 (90) | 1 (ref.) | 1 (ref.) | |||
| 10 to 49 | 816 (40) | 790 (97) | 78 | 712 (90) | 1.00 (0.96–1.05) | <0.001 | 0.94 (0.89–0.98) | <0.001 | ||
| 50 to 99 | 262 (13) | 259 (99) | 37 | 218 (85) | 0.95 (0.89–1.01) | 0.93 (0.87–0.99) | ||||
| ≥100 | 643 (31) | 641 (100) | 31 | 589 (95) | 1.06 (1.01–1.10) | 1.16 (1.09–1.22) | ||||
| [69] | [39] | |||||||||
| Parental determinants | Maternal age at delivery | <27 years | 287 (14) | 278 (97) | 24 | 254 (91) | 1 (ref.) | 1 (ref.) | ||
| 27-32 years | 799 (38) | 764 (96) | 67 | 697 (91) | 1.00 (0.96–1.04) | 0.95 | 1.00 (0.96–1.04) | |||
| >32 years | 1032 (49) | 997 (97) | 91 | 906 (91) | 0.99 (0.95–1.04) | 0.99 (0.95–1.03) | 0.93 | |||
| Maternal BCG | Yes | 356 (18) | 357 (96) | 39 | 318 (89) | 1 (ref.) | 1 (ref.) | |||
| No | 1638 (82) | 1661 (96) | 141 | 1520 (92) | 1.03 (0.99–1.07) | 0.18 | 1.03 (0.98–1.07) | 0.17 | ||
| [124] | [19] | |||||||||
| Parental smokingb | Yes | 313 (15) | 301 (96) | 29 | 272 (90) | 1 (ref.) | 1 (ref.) | |||
| No | 1790 (85) | 1738 (97) | 153 | 1585 (91) | 1.01 (0.97–1.05) | 0.61 | 1.00 (0.96–1.03) | 0.85 | ||
| [15] | ||||||||||
| Atopic dispositionc | Yes | 1349 (64) | 1297 (97) | 128 | 1169 (90) | 1 (ref.) | 1 (ref.) | |||
| No | 769 (36) | 742 (97) | 54 | 688 (93) | 1.03 (1.00–1.06) | 0.03 | 1.02 (0.99–1.05) | 0.13 | ||
| Other children <4 years of age in the homed | Yes | 445 (21) | 429 (96) | 39 | 390 (91) | 1 (ref.) | 1 (ref.) | |||
| No | 1656 (79) | 1608 (97) | 142 | 1446 (91) | 1.00 (0.96–1.03) | 0.81 | 0.99 (0.96–1.03) | 0.66 | ||
| [17] | [2] | |||||||||
| Individual determinants | Sex | Boys | 1096 (52) | 1060 (97) | 87 | 973 (92) | 1 (ref.) | 1 (ref.) | ||
| Girls | 1022 (48) | 979 (96) | 95 | 884 (90) | 0.98 (0.96–1.01) | 0.23 | 1.00 (0.97–1.02) | 0.73 | ||
| Prematurity | <37 weeks | 71 (3) | 63 (89) | 2 | 61 (97) | 1 (ref.) | 1 (ref.) | |||
| ≥37 weeks | 2047 (97) | 1976 (97) | 180 | 1796 (91) | 0.94 (0.90–0.98) | 0.01 | 0.96 (0.91–1.01) | 0.11 | ||
| Birth weight | <2500 g | 61 (3) | 53 (87) | 1 | 52 (98) | 1 (ref.) | 1 (ref.) | |||
| ≥2500 g | 2057 (97) | 1986 (97) | 181 | 1805 (91) | 0.92 (0.89–0.96) | <0.001 | 0.98 (0.94–1.03) | 0.52 | ||
| Caesarean section | No | 1694 (80) | 1629 (96) | 141 | 1488 (91) | 1 (ref.) | 1 (ref.) | |||
| Yes | 424 (20) | 410 (97) | 41 | 369 (90) | 0.99 (0.95–1.02) | 0.41 | 0.98 (0.95–1.02) | 0.38 | ||
| Child age at BCG vaccination | Day 2-7 | 554 (26) | 528 (95) | 49 | 479 (91) | 1 (ref.) | 1 (ref.) | |||
| Day 0-1 | 1564 (74) | 1511 (97) | 133 | 1378 (91) | 1.00 (0.96–1.02) | 0.74 | 0.99 (0.95–1.02) | 0.42 | ||
| Danish ethnicitye | Yes | 379 (18) | 357 (94) | 42 | 315 (88) | 1 (ref.) | 1 (ref.) | |||
| No | 1725 (82) | 1671 (97) | 139 | 1532 (92) | 1.04 (1.00–1.09) | 0.15 | 1.02 (0.98–1.06) | 0.60 | ||
| [14] | [11] | |||||||||
| Exclusively breastfeeda | Yes | 1210 (57) | 1168 (96) | 102 | 1066 (91) | 1 (ref.) | 1 (ref.) | |||
| No | 899 (43) | 869 (97) | 80 | 789 (91) | 1.00 (0.97–1.02) | 0.79 | 0.99 (0.96–1.02) | 0.71 | ||
| [9] | [2] | |||||||||
| Mid-upper arm circumferencef | 1 | 519 (25) | 517 (100) | 43 | 474 (92) | 1 (ref.) | 1 (ref.) | |||
| 2 | 521 (26) | 520 (100) | 46 | 474 (91) | 1.00 (0.96–1.03) | 0.88 | 0.98 (0.94–1.02) | 0.51 | ||
| 3 | 524 (26) | 523 (100) | 51 | 472 (90) | 0.98 (0.95–1.02) | 0.98 (0.92–1.01) | ||||
| 4 | 479 (23) | 476 (100) | 42 | 434 (91) | 1.00 (0.96–1.04) | 0.98 (0.93–1.03) | ||||
| [75] | [3] | |||||||||
| ΔWeight,g | 1 | 536 (26) | 533 (100) | 49 | 484 (91) | 1 (ref.) | 1 (ref.) | |||
| 2 | 495 (24) | 495 (100) | 48 | 447 (90) | 0.99 (0.95–1.03) | 0.72 | 0.99 (0.95–1.03) | 0.66 | ||
| 3 | 529 (26) | 526 (100) | 41 | 485 (92) | 1.01 (0.98–1.05) | 1.01 (0.97–1.06) | ||||
| 4 | 486 (24) | 484 (100) | 44 | 440 (91) | 1.00 (0.96–1.04) | 1.01 (0.96–1.07) | ||||
| [72] | [1] | |||||||||
Analysis adjusted for study site, vaccine batch, vaccine experience, maternal age at delivery, maternal BCG vaccination, parental smoking, atopic disposition, other children <4 years of age in the home, sex, prematurity, birth weight, caesarean section, child age at BCG vaccination, ethnicity, exclusively breastfeed, mid-upper arm circumference and Δweight.
Wald test.
Exclusively breastfeed: breastfeeding in the first 3 months of life.
Smoking: all types of smoking by parents included as well as inside and outside smoking in the first 12 month of life.
Atopic disposition: at least one first degree relative with atopic disease (physician-diagnosed atopic eczema, asthma or asthmatic bronchitis, allergic rhino conjunctivitis or food allergy).
Any other children <4 years of age in the house at least 5 days a week.
Danish ethnicity or other ethnicity.
Mid upper arm circumference (MUAC) is divided in quartiles: 1) 12.1 cm–14.9 cm, 2) 14.9 cm–15.6 cm, 3) 15.6 cm–16.5 cm and 4) 16.5 cm–20 cm.
Δweight: gain in weight from birth to the 13-month clinical examination; divided in quantiles: 1) 3415 g–6042 g, 2) 6044 g–6688 g, 3) 6689 g–7460 g, 4) 7464 g–10910 g.