Provision of Additional Risk Factors to Facilitate Country Utilization of the Risk Scoring Tool for Predicting Respiratory Syncytial Virus Hospitalization in Moderate-to-Late Preterm Infants

Introduction The Risk Scoring Tool (RST) for predicting respiratory syncytial virus hospitalization (RSVH) in 32 to 35 weeks’ gestational age (wGA) infants was developed and validated using data from seven northern hemisphere studies and included the risk factors: (1) proximity of birth to the RSV season, (2) second-hand smoke exposure, and (3) siblings and/or daycare (doi: 10.1002/ppul.23960). The RST was found to have good predictive accuracy (area under the receiver operating characteristic curve: 0.773) and provided cut-off scores of ≤19 for low-risk (RSVH risk: 1.0%), 20 to 45 for moderate-risk (3.3%), and 50 to 56 (9.5%) for high-risk infants. To facilitate local country utilization, analyses of additional risk factors that can be used to supplement the RST were undertaken.

Materials and Methods All other risk factors within the combined dataset with sufficient data for analysis were individually investigated using binary logistic regression, with RSVH in the first year of life the dependent variable. For risk factors available as continuous data, cut-offs were explored to maximize predictive accuracy. Standardized regression coefficients and univariate ORs with 95% CI and p-values are presented.

Results: Data for 13 additional risks factors were analyzed, seven of which increased the risk of RSVH (three significant), and six being protective (four significant; [Table A010]). Among these risk factors, the need for postnatal respiratory support increased the risk of RSVH most strongly (odds ratio [OR]: 1.61, 95% confidence interval [CI]: 1.16–2.23; p = 0.005). Assisted fertilization was most protective (OR: 0.39, 95% CI: 0.17–0.90; p = 0.026) perhaps due to increased sheltering of a child born to parents that required help to conceive. Three risk factors required cut-offs to be calculated: >4 in household (OR: 1.30, 95% CI: 1.08–1.58; p = 0.007); birthweight ≤1,400 g (OR: 1.24, 95% CI: 0.79–1.97; p = 0.358); and wGA 32^0/7 to 32^6/7 at birth (OR: 0.98, 95% CI: 0.70–1.39; p = 0.926).

Conclusion: This analysis provides coefficients for 13 risk factors that can be used to supplement the RST and aid local utilization.

Table A010

Risk factor	Univariate coefficient	Univariate odds ratio (95% Cl), p-Value
Postnatal respiratory support	0.473	1.61 (1.16–2.23), p = 0.005
Maternal education to primary/elementary level or less	0.438	1.55 (0.94–2.57), p = 0.089
Furred pets in household	0.321	1.38 (0.96–1.98), p = 0.080
>4 in household (including infant)	0.265	1.30 (1.08–1.58), p = 0.007
Birthweight ≤ 1,400 g	0.218	1.24 (0.79–1.97), p = 0.358
Atopy in primary family member	0.182	1.20 (1.00–1.44), p = 0.049
Neonatal resuscitation	0.091	1.10 (0.63–1.89), p = 0.758
Assisted fertilization	−0.951	0.39 (0.17–0.90), p = 0.026
Planned breastfeeding	−0.641	0.53 (0.44–0.54), p < 0.001
Multiple birth	−0.414	0.66 (0.54–0.81), p < 0.001
Cesarean birth	−0.266	0.77 (0.59–1.00), p = 0.048
Female sex	−0.152	0.86 (0.72–1.03), p = 0.097
wGA 320/7 to 326/7 at birth	−0.018	0.98 (0.70–1.39), p = 0.926

Abbreviations: Cl, confidence interval; wGA, weeks’ gestational age.

Conflict of Interest

None declared.