Hudson H M (School of Economic and Financial Studies, Macquarie University, North Ryde, NSW Australia 2113). An environmental and demographic analysis of otitis media in rural Australian aborigines. International Journal of Epidemiology 1984, 13: 73-82.Otitis media (OM) and tympanic scarring prevalence among rural Australian Aboriginal children is examined in relation to age, sex, community size and 34 environmental variables pertaining to living conditions and climate. The environmental variables are reduced to a smaller set of underlying factors via Principal Components Analysis. With age and sex standardized, a multivariate analysis is performed. OM prevalence is profoundly age-dependent, and is related negatively to community socioeconomic status and the presence of swimming facilities. Scarring prevalence is shown to be subject to substantial inter-observer variation, and with the appropriate adjustment manifests an inverse relationship with winter warmth. The data were collected under the National Trachoma and Eye Health Program.