OP6 ASSESSMENT OF THE INTERNATIONAL RISK SCORING TOOL FOR IDENTIFYING MODERATE-TO-LATE PRETERM INFANTS AT GREATEST RISK OF SEVERE RESPIRATORY SYNCYTIAL VIRUS INFECTION IN MALAYSIA

Asiah Kassim1, Bosco Paes2, Xavier Carbonell-Estrany3, Barry Rodgers-Gray4, Ian Keary4, Sze Chiang Lui1, Ching Hai Lee1, Nur Izyani Abdul Halim1, Fauziah Mat Ripen1, Shin Lam Koo1, Thimesha Vigneswaran1, Boon Hai Tan1, Yen Yin Lim1, John Fullarton4
1Hospital Tunku Azizah, Kuala Lumpur, Malaysia;
2McMaster University, Hamilton, Ontario, Canada;
3Hospital Clinic, Barcelona, Spain;
4Violicom Medical Limited, Aldermaston, United Kingdom

Introduction: 

The International Risk Scoring Tool (IRST) uses three risk factors (birth 3 months before to two months after the respiratory syncytial virus (RSV) season start date; smoking in the household and/or smoking while pregnant; siblings and/or daycare attendance) to categorise the risk of RSV hospitalisation (RSVH) in 32-35 weeks’ gestational age (wGA) infants. 

Objective:

We undertook the first assessment of the IRST in Malaysia, where RSV is non-seasonal (endemic). 

Methodology: 

Risk factor data for 32–35 wGA infants without comorbidities who had RSVH in the first year of life (cases) or not (controls) were assessed retrospectively at a tertiary Children’s Hospital in Malaysia. Data included the IRST risk factors, wGA, combined with two other risk factors for RSVH considered important in Malaysia; breastfeeding (defined as exclusive and given or planned from birth to 3 months of age) and socioeconomic status. Predictive accuracy was assessed by calculating the area under the receiver operating characteristic curve (AUROC), with ≥0.75 considered ‘good’.

Results: 

Generating the IRST (with wGA replacing chronological age) using Malaysian data resulted in an AUROC of 0.879 versus an AUROC of 0.773 for the original IRST. Adding breastfeeding and socioeconomic status improved the AUROC to 0.894. 

Conclusions: 

Our results strongly support that the IRST is predictive of RSVH in Malaysian moderate-to late preterm infants and that breastfeeding and socioeconomic status should be preferentially included when localising the tool. Adoption of the IRST provides a mechanism to target palivizumab to 32-35 wGA Malaysian infants who are most likely to benefit from prophylaxis.