Fig. 1. Flow chart of study subject enrollment. Four hundred patients admitted for typical signs and symptoms of lower respiratory tract infections (LRTIs) were eligible for enrollment. Nasopharyngeal swabs from 192 of these patients (48%) showed positive results upon virus polymerase chain reaction testing. After excluding subjects in line with the exclusion criteria (no response to questionnaire, prematurity, age-matching, and cardiac anomaly), a total of 142 subjects were included in the final analysis. These subjects consisted of 70 children diagnosed with LRTIs with wheezing and 72 children diagnosed with LRTIs without wheezing.
