Four treatment trials (n=1,766 children; two trials with each drug) and three prophylaxis trials (n=863 children; one trial with oseltamivir and two with zanamivir) were included. One treatment trial was rated high quality, the others reported insufficient details. Prophylaxis trials were of moderate quality.
Treatment with oseltamivir or zanamivir reduced median time to resolution of symptoms, return to normal activities or both by between 0.5 and 1.5 days. The difference between treatment and control groups was statistically significant in two of the four trials. Treatment with oseltamivir did not significantly reduce exacerbations or improve peak flow in children with asthma (one trial). Treatment was not associated with an overall reduction in use of antibiotics (two trials).
A 10 day course of prophylaxis with oseltamivir or zanamivir was associated with a statistically significant 8% absolute reduction in the incidence of symptomatic influenza in the households of children with clinical influenza (risk difference -0.08, 95% CI: -0.12 to -0.05, I2=0%).
Pooling of data on nausea, vomiting and diarrhoea from the four treatment trials revealed significant heterogeneity (I2=75%). Subgroup analysis indicated that oseltamivir significantly increased risk of vomiting (risk difference 0.05, 95% CI: 0.02 to 0.09) while zanamivir did not (risk difference 0.00, 95% CI: -0.02 to 0.02). Results for other outcomes were reported.