Absent otoacoustic emissions predict otitis media in young Aboriginal children: a birth cohort study in Aboriginal and non-Aboriginal children in an arid zone of Western Australia.

BACKGROUND: Otitis media (OM) is the most common paediatric illness for which antibiotics are prescribed. In Australian Aboriginal children OM is frequently asymptomatic and starts at a younger age, is more common and more likely to result in hearing loss than in non-Aboriginal children. Absent transient evoked otoacoustic emissions (TEOAEs) may predict subsequent risk of OM. METHODS: 100 Aboriginal and 180 non-Aboriginal children in a semi-arid zone of Western Australia were followed regularly from birth to age 2 years. Tympanometry was conducted at routine field follow-up from age 3 months. Routine clinical examination by an ENT specialist was to be done 3 times and hearing assessment by an audiologist twice. TEOAEs were measured at ages <1 and 1-2 months. Cox proportional hazards model was used to investigate the association between absent TEOAEs and subsequent risk of OM. RESULTS: At routine ENT specialist clinics, OM was detected in 55% of 184 examinations in Aboriginal children and 26% of 392 examinations in non-Aboriginal children; peak prevalence was 72% at age 5-9 months in Aboriginal children and 40% at 10-14 months in non-Aboriginal children. Moderate-severe hearing loss was present in 32% of 47 Aboriginal children and 7% of 120 non-Aboriginal children aged 12 months or more. TEOAE responses were present in 90% (46/51) of Aboriginal children and 99% (120/121) of non-Aboriginal children aged <1 month and in 62% (21/34) and 93% (108/116), respectively, in Aboriginal and non-Aboriginal children at age 1-2 months. Aboriginal children who failed TEOAE at age 1-2 months were 2.6 times more likely to develop OM subsequently than those who passed. Overall prevalence of type B tympanograms at field follow-up was 50% (n = 78) in Aboriginal children and 20% (n = 95) in non-Aboriginal children. CONCLUSION: The burden of middle ear disease is high in all children, but particularly in Aboriginal children, one-third of whom suffer from moderate-severe hearing loss. In view of the frequently silent nature of OM, every opportunity must be taken to screen for OM. Measurement of TEOAEs at age 1-2 months to identify children at risk of developing OM should be evaluated in a routine health service setting.

The effect of passive smoking on the risk of otitis media in Aboriginal and non-Aboriginal children in the Kalgoorlie-Boulder region of Western Australia.

OBJECTIVES: To determine the risk of otitis media (OM) associated with passive smoking in young children, and any competing effect between passive smoking and childcare attendance. DESIGN, PARTICIPANTS AND SETTING: Prospective cohort study of 100 Aboriginal and 180 non-Aboriginal children born in Kalgoorlie Regional Hospital between 1 April 1999 and 31 January 2003. These children underwent routine clinical examinations by an ear, nose and throat specialist up to three times before the age of 2 years, and tympanometry at routine field follow-up visits from the age of 4 months. Childrens' mothers were interviewed at 1-3 weeks postpartum to provide sociodemographic data. MAIN OUTCOME MEASURES: Associations between OM and exposure to environmental tobacco smoke (ETS) and childcare attendance. RESULTS: 82 Aboriginal and 157 non-Aboriginal children attended for routine clinical examinations. OM was diagnosed at least once in 74% of Aboriginal children and 45% of non-Aboriginal children; 64% of Aboriginal children and 40% of non-Aboriginal children were exposed to ETS. Exposure to ETS increased the risk of specialist-diagnosed OM in Aboriginal children (OR, 3.54; 95% CI, 1.68-7.47); few attended childcare. Non-Aboriginal children exposed to ETS but not attending childcare were at increased risk of OM (OR, 1.91; 95% CI, 1.07-3.42) while those attending childcare had no increased smoking-related risk. Tympanometry was performed on 87 Aboriginal and 168 non-Aboriginal children; a type B tympanogram (suggesting fluid in the middle ear) was also associated with passive smoking in Aboriginal children. CONCLUSIONS: Reducing the exposure of children to ETS is a public health priority, especially for the Aboriginal population. A smoke-free environment will help reduce the burden of OM.

The Kalgoorlie Otitis Media Research Project: rationale, methods, population characteristics and ethical considerations.

Otitis media (OM) is one of the most common paediatric illnesses for which medical advice is sought in developed countries. Australian Aboriginal children suffer high rates of OM from early infancy. The resultant hearing loss can affect education and quality of life. As numerous factors contribute to the burden of OM, interventions aimed at reducing the impact of single risk factors are likely to fail. To identify key risk factors and understand how they interact in complex causal pathways, we followed 100 Aboriginal and 180 non-Aboriginal children from birth to age 2 years in a semi-arid zone of Western Australia. We collected demographic, obstetric, socio-economic and environmental data, breast milk once, and nasopharyngeal samples and saliva on seven occasions. Ear health was assessed by clinical examination, tympanometry, transient evoked otoacoustic emissions and audiometry. We considered the conduct of our study in relation to national ethical guidelines for research in Aboriginal and Torres Strait Islander health. After 1 year of community consultation, the study was endorsed by local committees and ethical approval granted. Fieldwork was tailored to minimise disruption to people's lives and we provided regular feedback to the community. We saw 81% of non-Aboriginal and 65% of Aboriginal children at age 12 months. OM was diagnosed on 55% and 26% of routine clinical examinations in Aboriginal and non-Aboriginal children respectively. Aboriginal mothers were younger and less educated, fewer were employed and they lived in more crowded conditions than non-Aboriginal mothers. Sixty-four per cent of Aboriginal and 40% of non-Aboriginal babies were exposed to environmental tobacco smoke. Early consultation, provision of a service while undertaking research, inclusion of Aboriginal people as active members of a research team and appropriate acknowledgement will assist in ensuring successful completion of the research.