In our new Gawker and Buzzfeed-fueled, short-attention span reality, attention-grabbing headlines are essential. So, let me come up with the modern headline for news coverage of this latest article, published in Pediatrics: “Is your child’s next cold a killer?”
Seriously, as covered by Medscape (subscription required):
“As many as 1 in 3 children seeking treatment in the emergency department for influenza-like illnesses (ILI) at the peak of influenza season are at high risk of suffering severe complications, such as pneumonia.”
But, that’s hardly the case. The study upon which they report is an observational cohort of ILI presenting to a tertiary children’s hospital. To be eligible for inclusion, children needed to have ILI, defined as fever + cough/sore throat, and have “moderate to severe” symptoms. However, their definition of “moderate to severe” is not based on any specific clinical criteria – it’s based off the surrogate of whether a clinician judged venipuncture and viral testing necessary.
So, 125,940 children were screened during the study period, and this cohort comprises the, presumably, sickest 241 of those. Of those 241, over half had one of a predefined list of high-risk conditions: asthma, neurologic/neuromuscular disease, respiratory disease, heart disease, or immunosuppression. And, yes, about 40% of each cohort developed a complication – most frequently pneumonia. But, it should not be concluded there are killer viruses everywhere – rather, the sickest ILI, particularly those children who presumably appeared ill despite lacking underlying chronic illness, are the tiny cohort at higher risk of subsequent complication.
The authors also try to single out H1N1 influenza as an independent risk factor for subsequent complications. 11/29 patients with H1N1 influenza developed pneumonia, compared with 1/20 patients without, leading to their conclusion H1N1 confers particular risk. However, 22/29 of patients diagnosed with H1N1 carried high-risk comorbidities, compared with only 10/20 in the non-H1N1 influenza cohort. Yes, H1N1 probably increases risk of respiratory complications, but these data may not reliably support their conclusion.
“Severe Complications in Influenza-like Illnesses”
http://pediatrics.aappublications.org/content/early/2014/07/29/peds.2014-0505.abstract