2.2-Data collection for risk factors, clinical course, and
outcomes
We reviewed risk factors, clinical course, and outcomes of all patients
eligible for the study. The potential risk factors for severe LRTI
regarding the literature7,13–17 were abstracted from
the electronic medical record. The age, gender, prematurity
(<37 weeks), history of atopy (clinician-confirmed atopy),
exposure to tobacco smoke (smokers in the household), malnutrition
status (assessed with weight-for-height standard deviation score
[SDS])18, the number and type of virus, underlying
condition (immunosuppression [IS], neuromuscular disease [NMD],
chronic lung disease [CLD], hemodynamically significant congenital
heart disease [CHD], and previous history of LRTI), neutrophil and
lymphocyte status for age19, c-reactive protein (CRP)
value, oxygen requirement (defined as peripheral oxyhemoglobin
saturation <92%), and admission to the ICU (defined as those
admitted if they required high-flow nasal cannula oxygen
[HFNCO]/bilevel positive airway pressure [BiPAP]/IMV) or short
term unit were collected. Children with multiple underlying conditions
were included in the group considered having a higher risk for
underlying disease. Patients with IS/NMD considered the highest-risk,
followed by CLD, CHD, and then the previous history of LRTI.