Australian Aboriginal children have higher hospitalization rates for otitis media but lower surgical procedures than non-Aboriginal children: A record linkage population-based cohort study

Abstract

Introduction: Otitis media (OM) is one of the most common infectious diseases affecting children globally and the most common reason for antibiotic prescription and paediatric surgery. Australian Aboriginal children have higher rates of OM than non-Aboriginal children; however, there are no data comparing OM hospitalization rates between them at the population level. We report temporal trends for OM hospitalizations and in-hospital tympanostomy tube insertion (TTI) in a cohort of 469,589 Western Australian children born between 1996 and 2012.

Materials and methods: We used the International Classification of Diseases codes version 10 to identify hospitalizations for OM or TTI recorded as a surgical procedure. Using age-specific population denominators, we calculated hospitalization rates per 1,000 child-years by age, year and level of socio-economic deprivation.

Results: There were 534,674 hospitalizations among 221,588 children hospitalized at least once before age 15 years. Aboriginal children had higher hospitalization rates for OM than non-Aboriginal children (23.3/1,000 [95% Confidence Interval (CI) 22.8,24.0] vs 2.4/1,000 [95% CI 2.3,2.4] child-years) with no change in disparity over time. Conversely non-Aboriginal children had higher rates of TTI than Aboriginal children (13.5 [95% CI 13.2,13.8] vs 10.1 [95% CI 8.9,11.4]). Children from lower socio-economic backgrounds had higher OM hospitalization rates than those from higher socio-economic backgrounds, although for Aboriginal children hospitalization rates were not statistically different across all levels of socio-economic disadvantage. Hospitalizations for TTI among non-Aboriginal children were more common among those from higher socio-economic backgrounds. This was also true for Aboriginal children; however, the difference was not statistically significant. There was a decline in OM hospitalization rates between 1998 and 2005 and remained stable thereafter.

Conclusion: Aboriginal children and children from lower socio-economic backgrounds were over-represented with OM-related hospitalizations but had fewer TTIs. Despite a decrease in OM and TTI hospitalization rates during the first half of the study for all groups, the disparity between Aboriginal and non-Aboriginal children and between those of differing socioeconomic deprivation remained.

Fig 1. Flow chart of record linkage of a cohort of 469,589 children born in Western Australia between 1996 and 2012 with records of hospitalization for otitis media or tympanostomy tube insertion procedure before 15 years of age.

Fig 2. Rates of hospitalization for non-procedural otitis media and tympanostomy tube insertion per 1,000 child-years for non-Aboriginal and Aboriginal children born in Western Australia between 1996 and 2012.

Fig 3

Rates of hospitalization for non-procedural otitis media per 1,000 child-years for non-Aboriginal (top) and Aboriginal (bottom) children born in Western Australia between 1996 and 2012. Note difference in scale.

Fig 4

Hospitalization rates for tympanostomy tube insertion among children 12 to 35 months born in Western Australia between 1996 and 2012 (top). Non-Aboriginal children aged between 12 and 23 months and Aboriginal children aged 24 to 47 months born in remote regions in Western Australia between 1996 and 2012. (3-year moving average).