Antiviral Use in Canadian Children Hospitalized for Influenza

Objectives: Antivirals are recommended for children hospitalized with influenza but are underutilized. We describe antiviral prescribing during influenza admissions in Canadian pediatric centers and identify factors associated with antiviral use.

Methods: We performed active surveillance for laboratory-confirmed influenza hospitalizations among children ≤16 years old at the 12 Canadian Immunization Monitoring Program Active hospitals, from 2010-2011 to 2018-2019. Logistic regression analyses were used to identify factors associated with antiviral use.

Results: Among 7545 patients, 57.4% were male; median age was 3 years (interquartile range: 1.1-6.3). Overall, 41.3% received antiviral agents; 72.8% received antibiotics. Antiviral use varied across sites (range, 10.2% to 81.1%) and influenza season (range, 19.9% to 59.6%) and was more frequent in children with ≥1 chronic health condition (52.7% vs 36.7%; P < .001). On multivariable analysis, factors associated with antiviral use included older age (adjusted odds ratio [aOR] 1.04 [95% confidence interval (CI), 1.02-1.05]), more recent season (highest aOR 9.18 [95% CI, 6.70-12.57] for 2018-2019), admission during peak influenza period (aOR 1.37 [95% CI, 1.19-1.58]), availability of local treatment guideline (aOR 1.54 [95% CI, 1.17-2.02]), timing of laboratory confirmation (highest aOR 2.67 [95% CI, 1.97-3.61] for result available before admission), presence of chronic health conditions (highest aOR 4.81 [95% CI, 3.61-6.40] for cancer), radiographically confirmed pneumonia (aOR 1.39 [95% CI, 1.20-1.60]), antibiotic treatment (aOR 1.51 [95% CI, 1.30-1.76]), respiratory support (1.57 [95% CI, 1.19-2.08]), and ICU admission (aOR 3.62 [95% CI, 2.88-4.56]).

Conclusions: Influenza antiviral agents were underused in Canadian pediatric hospitals, including among children with high-risk chronic health conditions. Prescribing varied considerably across sites, increased over time, and was associated with patient and hospital-level characteristics. Multifaceted hospital-based interventions are warranted to strengthen adherence to influenza treatment guidelines and antimicrobial stewardship practices.