Predictive value of the respiratory syncytial virus risk-scoring tool in the term infant in Canada

ABSTRACT

Background: Palivizumab prophylaxis against respiratory syncytial virus (RSV) infection has been widely adopted for high-risk infants during the RSV season, based on country-specific guidelines.

Objective: To determine if a validated, risk-scoring tool (RST), can be applied to term, RSV-positive infants seen in the emergency room (ER) to predict need for hospitalization, in order to target prophylaxis cost effectively at a selected group of children.

Design: Retrospective, descriptive study.

Setting: McMaster Children's Hospital in Hamilton, Ontario, Canada.

Participants: A total of 72, consecutive, term, RSV-positive cases were identified retrospectively, from November through April during the 2006–2007 RSV season.

Methods: A questionnaire/chart review was conducted on 68 of 72 cases, to determine risk categories based on the RST. Four, trained abstractors, extracted pertinent data from the medical records of RSV-positive patients. Means, standard deviations (SD), and percents were used to describe the study variables for hospitalized and ER patients discharged home. Chi-square tests were used to compare infants’ risk factors to hospitalization. ANOVA was used for comparisons within and between risk groups and RST scores. A p-value of <0.05 was considered statistically significant.

Results: The majority of infants scored in the low-risk category (n = 44), versus moderate (n = 16) or high risk (n = 8). Within the low-risk category, 27 (61%) of children were admitted to hospital compared to 17 (39%) who were treated in the ER and discharged home. The mean RST scores for those admitted to the pediatric intensive care unit/ward, the ward only, or those discharged home from the ER were 48.3 (n = 10), 41.0 (n = 36), and 36.5 (n = 22), respectively (p = 0.17). The mean number of risk factors for those discharged home versus hospitalized patients was 2.5 (1.3) and 2.97 (1.13), respectively (p = 0.15). Only two of eight cases in the high-risk group required intensive care.

Conclusions: Overall, the risk-scoring tool did not discriminate between low versus moderate- to high-risk RSV-positive term infants who require hospitalization which has cost implications, since universal prophylaxis of this cohort would be financially prohibitive. A larger study is necessary to establish risk factors that more accurately determine RSV hospitalization among term infants.

Keywords: :

• Respiratory syncytial virus
• Risk factors
• Prophylaxis
• Palivizumab
• Term infant

Transparency

Declaration of funding

This study was conducted independently by the investigators and was not funded by any agency.

Declaration of financial/other relationships

Acknowledgment

The authors acknowledge the support of the pediatric nurses and physicians at McMaster Children's Hospital for their assistance with the project. B.P. has disclosed that he is currently Co-Principal Investigator on a multicenter investigator initiated research study entitled ‘CARESS’ (Canadian Registry of Synagis).

The Principal Investigator is supported by a grant in aid of research by Abbott Laboratories, Ltd. The investigators for the CARESS study maintain control over any abstracts and presentations arising from the data and the rights to publish.

The data in this paper were presented at the Canadian Paediatric Society, 85th Annual Conference, June 24–28, 2008, Victoria, British Columbia, Canada; and the 2nd Congress of the European Academy of Paediatrics, October 24–28, 2008, Nice, France.