Letters to the Editor

The palivizumab patchwork: Variation in guidelines for Respiratory Syncytial Virus prevention across Canadian provinces and territories

BACKGROUND

Respiratory Syncytial Virus is the leading cause of hospitalization for lower respiratory tract infection in young children. The only preventive intervention is an anti-Respiratory Syncytial Virus (RSV) monoclonal antibody (palivizumab, Synagis) administered as monthly intramuscular injections during the winter. Recommendations for palivizumab use have been published by the Canadian Paediatric Society (CPS) and other agencies. We sought to determine if there was interjurisdictional variation in eligibility for palivizumab across provinces and territories and in comparison to CPS recommendations, as well as the nature of this variation.

METHODS

Eligibility criteria were obtained from personnel coordinating provincial and territorial programs and from public governmental websites.

RESULTS

All 13 jurisdictions provided information about their palivizumab eligibility policies. No province or territory (PT) follows CPS guidelines exactly and substantial heterogeneity exists among jurisdictions. All PT jurisdictions provide prophylaxis in the first year of life to infants with hemodynamically significant congenital heart disease or chronic lung disease on ongoing therapy for those conditions, and to premature children in remote areas. In general, PTs had more liberal policies than the CPS, offering palivizumab to a wide range of children with conditions such as cystic fibrosis, Down syndrome or to moderately premature children with risk factors.

CONCLUSIONS

Substantial variation in PT criteria for RSV prevention exists in Canada, and no jurisdiction follows CPS criteria exactly. Variability in subnational policy may reflect access to human or material resources, varying interpretation of evidence for efficacy, variation in epidemiology, the effect of local pressures, or advocacy.

Estimating Respiratory Syncytial Virus-associated Hospitalization in the First Year of Life Among Infants Born at 32-35 Weeks of Gestation

BACKGROUND

Prophylaxis against respiratory syncytial virus-associated hospitalization (RSV-H) with anti-RSV monoclonal antibody is not considered cost-effective for routine use in most jurisdictions. The aim of this study was to develop a scoring tool to estimate local risk of RSV-H in the first year of life among moderately premature infants to assist in prophylaxis decision making.

METHODS

A retrospective cohort was constructed from population-based databases in Nova Scotia, Canada, to follow 32- to 35-week gestation infants from the prenatal period to <12 months of age, from 1998 to 2008. Potential risk factors were entered into the logistic regression model, where the dependent variable was RSV-H. Receiver operator characteristic analysis demonstrated cutoff scores producing the highest predictive accuracy, and the likelihood ratio test was used to select the final set of variables for the predictive tool.

RESULTS

In 2811 eligible infants, the overall RSV-H rate was 3.1% (88/2811). Of 17 variables considered, 3 were used to create the scoring tool: birth during December to February, household smoke exposure and household crowding. The positive likelihood ratios of predictive tool scores for high, moderate and low of RSV-H were 3.57, 3.38 and 1.95, whereas posttest probabilities (risk of RSV-H) were 11.4%, 10.8% and 1.6%, respectively.

CONCLUSIONS

While able to predict infants at low risk of RSV-H, the tool did not discriminate high from moderate risk infants. The tool could be used in anticipatory care to help educate families about reducing risk of serious RSV illness in their newborn.