Table 1.
Sociodemographic and clinical variables at baseline
| Variables | All infants(n=161) | DS cohort(n=93) | Non‐DS cohort(n=68) | P value |
|---|---|---|---|---|
| Sex, no. (%) | ||||
| Males | 102 (63.3) | 59 (63.4) | 43 (63.2) | .978 |
| Females | 59 (36.6) | 34 (36.6) | 25 (36.8) | |
| Age, days, mean (SD) | 235.4 (172.0) | 223.2 (162.1) | 252.1 (184.6) | .425 |
| Weight, kg, mean (SD) | 6.5 (2.6) | 6.0 (2.4) | 7.2 (2.7) | .007 |
| Ethnicity, no. (%) | ||||
| Caucasian | 141 (87.6) | 78 (81.7) | 65 (95.6) | .058 |
| Othera | 20 (12.4) | 17 (18.3) | 3 (4.4) | |
| Gestational age at birth, weeks, mean (SD) | 38.3 (1.5) | 37.7 (1.4) | 39.1 (1.3) | <.001 |
| Breastfeeding duration, months, mean (SD) | 94.2 (110.6) | 82.6 (106.7) | 109.5 (114.5) | .069 |
| Twins, no.(%) | 3 (1.9) | 3 (3.2) | 0 | .263 |
| Father's age, years, mean (SD) | 36.3 (6.1) | 37.2 (7.0) | 35.1 (4.4) | .007 |
| Mother's age, mean (SD) | 35.0 (5.1) | 35.8 (5.7) | 33.8 (3.9) | .004 |
| Siblings <11 y of age, median (IQR) | 0 (0‐1) | 1 (0‐1) | 0 (0‐1) | .109 |
| Nursery attendance or early care, no. (%) | 63 (39.1) | 47 (50.5) | 16 (23.5) | .0004 |
| Siblings in nursery/school, median (IQR) | 0.5 (0‐1) | 1 (0‐1) | 0 (0‐1) | .007 |
| Place of residence, no. (%) | ||||
| Urban | 125 (77.6) | 66 (71.0) | 59 (86.8) | .017 |
| Rural | 36 (22.4) | 27 (29.0) | 9 (13.2) | |
| Current smokers, no. (%) | ||||
| Father | 43 (75.4) | 25 (71.4) | 18 (81.8) | .336 |
| Mother | 24 (42.1) | 16 (45.7) | 8 (36.4) | .486 |
| Family members | 57 (35.4) | 35 (37.6) | 22 (32.5) | .457 |
| Members in the household, median (IQR) | 4 (3‐4) | 4 (3‐5) | 3 (3‐4) | .0006 |
| Education level of the parents, no. (%) | ||||
| Low | 16 (9.9) | 14 (15.1) | 2. (2.9) | .013 |
| Medium | 57 (35.4) | 35 (37.6) | 22 (32.5) | |
| High | 87 (54.0) | 43 (46.2) | 44 (64.7) | |
| Previous hospitalizations, no. (%) | ||||
| RSV infection | 11 (6.8) | 10 (10.7) | 1 (1.4) | .025 |
| Other reasons | 40 (24.8) | 35 (37.6) | 5 (7.3) | <.001 |
| Prophylaxis against RVS, no. (%) | 33 (20.5) | 33 (35.5) | 0 | <.001 |
| Doses, mean (SD) | 3.8 (1.6) | 3.8 (1.6) | 0 | |
| Compliance vaccination calendar, no. (%) | 157 (97.5) | 89 (95.7) | 68 (100) | .138 |
a
Black, Hispanic, Asiatic, Arabs.