Objective: Temporal trends in paediatric encounters for otitis media (OM) were last characterised and observed to be steadily increasing from 1975 to the mid-1990 s. The present study uses an ecological design to quantify trends in paediatric encounters for OM concurrent with a period of decline of an important risk factor, secondhand smoke (SHS) exposure among children.
Patients and methods: Annual paediatric ambulatory visit and hospital discharge rates for children ≤ 6 years with OM as primary diagnosis were computed with nationally representative data for 1993-2006. Percentages of households with children ≤ 6 years and no-smoking rules were computed using Tobacco Use Supplement to the Current Population Survey data. Average annual percentage changes were determined for covariate-adjusted rates of paediatric encounters for OM using joinpoint analysis.
Results: While percentages of homes with children and no-smoking rules increased by 89% from 45.5% in 1993 to 86.1% in 2006, average annual covariate-adjusted paediatric encounters for OM decreased by 4.6% (95% CI 4.5% to 4.8%) for ambulatory visits and by 9.8% (95% CI 9.1% to 10.6%) for hospital discharges. Coverage by 7-valent pneumococcal conjugate vaccination (PCV7) increased since 2002, while little variation occurred in other potentially associated risk factors.
Conclusions: Paediatric encounter rates for OM decreased steadily over a 13-year period reversing a previously reported long-term increasing trend reported. Reduced SHS exposure, PCV7 coverage since 2002 and other factors may have contributed to the decline. Further research is needed to provide direct estimates of paediatric encounter rates in exposed and unexposed populations for causal inference.