RESUMEN
OBJECTIVE: To quantify the relationship between recurrent wheezing (RW) in the third year of life and respiratory syncytial virus (RSV) infection, prematurity, and neonatal oxygen exposure. DESIGN: Retrospective cohort study linking inpatient, outpatient, and laboratory databases for cohort assembly and logistic regression analysis. SETTING: Integrated health care delivery system in Northern California. PARTICIPANTS: A total of 71,102 children born from 1996 to 2002 at 32 weeks' gestational age or later who were health plan members for 9 or more months in their first and third years. MAIN EXPOSURES: Laboratory-confirmed, medically attended RSV infection during first year and supplemental oxygen during birth hospitalization. OUTCOME MEASURES: Recurrent wheezing, quantified through outpatient visits, inpatient hospital stays, and asthma prescriptions. RESULTS: The rate of RW in the third year of life was 16.23% among premature infants with RSV and 6.22% among those without RSV. The risk of RW increased among infants who had an RSV outpatient encounter (adjusted odds ratio [AOR], 2.07; 95% CI, 1.61-2.67), uncomplicated RSV hospitalization (AOR, 4.66; 95% CI, 3.55-6.12), or prolonged RSV hospitalization (AOR, 3.42; 95% CI, 2.01-5.82) compared with infants without RSV encounters. Gestational age of 34 to 36 weeks was associated with increased risk of RW (AOR, 1.23; 95% CI 1.07-1.41) compared with 38 to 40 weeks, while a gestational age of 41 weeks or more was protective (AOR, 0.90; 95% CI, 0.81-0.99). Supplemental oxygen exposure was associated with increased risk at all levels. CONCLUSION: Laboratory-confirmed, medically attended RSV infection, prematurity, and exposure to supplemental oxygen during the neonatal period have independent associations with the development of RW in the third year of life.