Small area population disease burden.
Small area health statistics has assumed increasing importance as the focus of population and public health moves to a more individualised approach of smaller area populations. Small populations and low event occurrence produce difficulties in interpretation and require appropriate statistical methods, including for age adjustment. There are also statistical questions related to multiple comparisons. Privacy and confidentiality issues include the possibility of revealing information on individuals or health care providers by fine cross-tabulations. Interpretation of small area population differences in health status requires consideration of migrant and Indigenous composition, socioeconomic status and rural-urban geography before assessment of the effects of physical environmental exposure and services and interventions. Burden of disease studies produce a single measure for morbidity and mortality--disability adjusted life year (DALY)--which is the sum of the years of life lost (YLL) from premature mortality and the years lived with disability (YLD) for particular diseases (or all conditions). Calculation of YLD requires estimates of disease incidence (and complications) and duration, and weighting by severity. These procedures often mean problematic assumptions, as does future discounting and age weighting of both YLL and YLD. Evaluation of the Victorian small area population disease burden study presents important cross-disciplinary challenges as it relies heavily on synthetic approaches of demography and economics rather than on the empirical methods of epidemiology. Both empirical and synthetic methods are used to compute small area mortality and morbidity, disease burden, and then attribution to risk factors. Readers need to examine the methodology and assumptions carefully before accepting the results.
Taylor
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R
Department of Public Health and Community Medicine, Faculty of Medicine, University of Sydney, New South Wales. richardt@health.usyd.edu.au
D000206:Actuarial Analysis; D017281:Cost of Illness; D006233:Persons with Disabilities; D006306:Health Surveys; D006801:Humans; D009017:Morbidity; D009026:Mortality; D011634:Public Health / Q000706:statistics & numerical data; D017062:Small-Area Analysis; D014739:Victoria / Q000453:epidemiology