Table 1 Description of variables in the Barwon Infant Study and their respective level of missingness in the full cohort and subset in participants with complete outcome data
Variable | Label | Full cohort (n=786) | Subset (n=325) | ||
|---|---|---|---|---|---|
Summary | Missing (%) | Summary | Missing (%) | ||
Outcome | |||||
Food allergy at 1 year – present – n(%) | FoodAllergy | 61 (7.8) | 0 (0.0) | 61 (18.8) | 0 (0.0) |
Exposure | |||||
Vitamin D insufficiency at birth – present – n(%) | VDI | 132 (45.1) | 493 (62.7) | 109 (44.3) | 79 (24.3) |
Confounders | |||||
Ethnicity – “Caucasian” – n(%) | Eth | 573 (73.2) | 3 (0.4) | 240 (74.3) | 2 (0.6) |
Domestic pet ownership – present – n(%) | PetOwn | 602 (77.4) | 8 (1.0) | 239 (74.2) | 3 (0.9) |
Antenatal vitamin D usage – present – n(%) | AnteVD | 460 (79.3) | 206 (26.2) | 193 (76.0) | 71 (21.9) |
History of family allergy – present – n(%) | FamHx | 675 (86.9) | 9 (1.2) | 284 (88.2) | 3 (0.9) |
Number of siblings – n(%) | NSib | 0 (0.0) | 0 (0.0) | ||
None | 320 (40.7) | 113 (34.8) | |||
One | 281 (35.8) | 130 (40.0) | |||
Two or more | 185 (23.5) | 82 (25.2) | |||
Auxiliary | |||||
Maternal age at birth (years) – mean(SD) | MAge | 32.1 (4.8) | 3 (0.3) | 33.0 (4.3) | 0 (0.0) |
SEIFA tertile – n(%) | SEIFA | 14 (1.8) | 6 (1.9) | ||
Low | 172 (22.3) | 77 (24.1) | |||
Middle | 148 (19.2) | 61 (19.1) | |||
High | 452 (58.6) | 181 (56.7) | |||