Table 4.
Multivariate analysis of risk factors associated with RSVH in the first year of life for infants born at 32/33–35 wGA
| Risk factors | Odds ratio (95% confidence interval) | |||||
|---|---|---|---|---|---|---|
| FLIP study [7] (n = 557) | FLIP-2 study [8] (n = 5441) | PICNIC study [9] (n = 1758) | RISK study [10] (n = 2421) | RISK-II study [11] (n = 1564) | PONI study [12] (n = 2390) | |
| Exposure | ||||||
| Age at start of RSV season (a≤10 weeks, bbirth November-January, cbirth August 14th to December 1st, ≤3 monthsd) |
3.95a (2.65–5.90) P ≤ 0.001 |
2.99a (2.23–4.01) P ≤ 0.001 |
4.88b (2.57–9.29) P < 0.001 |
2.6c (1.6–4.2) P < 0.001 |
2.4c (1.8–3.2) P < 0.001 |
2.10d P = 0.0422 |
| Siblings (aschool age, bschool-age siblings or day care attendance, cpre-school-age, dsiblings or day care attendance, echildren aged 4–5 years) |
2.85a (1.88–4.33) P ≤ 0.001 |
2.04b (1.53–2.74) P ≤ 0.001 |
2.76c (1.51–5.03) P = 0.001 |
4.7d (1.7–13.1) P = 0.003 |
5.3d (2.8–10.10) P < 0.001 |
2.28e P = 0.0038 |
| Crowding at home (≥4a without subject and school age siblings, >5b counting subject) |
1.91a (1.19–3.07) P = 0.0074 |
– |
1.69b (0.93–3.10) P = 0.088 |
– | – | – |
| Day care attendance | – | – |
12.32 (2.56–59.34) P = 0.002 |
– | – | – |
| Social factors | ||||||
| Exposure to ≥2 smokersa, smoking of familyb | – | – |
1.71a (0.97–3.00) P = 0.064 |
– | – |
3.18 P < 0.0001 |
| Smoking during pregnancy | – |
1.61 (1.16–2.25) P = 0.0044 |
– | – | – | – |
| Breast feeding ≤2 monthsa |
3.26a (1.96–5.42) P ≤ 0.001 |
– | – |
1.7a (1.0–2.7) P = 0.04 |
1.6b (1.2–2.2) P = 0.003 |
– |
| Biological factors | ||||||
| Small for gestational age (<10th percentile) | – | – |
2.19 (1.14–4.22) P = 0.019 |
– | – | – |
| Male sex | – | – |
1.91 (1.10–3.31) P = 0.02 |
– | – | – |
| Family history of wheezing |
1.90 (1.19–3.01) P = 0.0068 |
– | – | – | – | – |
| Family history of eczemaa/atopyb in first degree relative, maternal atopic constitutionc, paternal atopyd | – | – |
0.42a (0.18–0.996) P = 0.049 |
1.9b (1.1–3.2) P = 0.01 |
1.5c (1.1–2.1) P = 0.01 |
3.28d P < 0.0001 |
| Non-hemodynamically significant congenital heart disease diagnosis | – | – | – | – | – |
4.09 P = 0.0077 |
| Maternal age ≤25 years | – | – | – | – | – |
2.72 P = 0.0009 |
| Low maternal education | – | – | – | – | – |
1.79 P = 0.0426 |
| Medical factors | ||||||
| Neonatal respiratory support | – | – | – | – |
2.2 (1.6–3.0) P < 0.001 |
– |
| Hospital stay <7 days (at birth) | – | – | – | – | – |
2.14 P = 0.0113 |
Maternal atopic constitution = maternal hay fever, asthma or eczema; Neonatal respiratory support = oxygen/nasal mask/CPAP and/or mechanical ventilation
RSV(H) respiratory syncytial virus (hospitalization)