Accounting for the Distribution of Adverse Birth Outcomes in Ontario: A Hierarchical Analysis of Provincial and Local Outcomes

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dc.date.accessioned2013-04-29T19:12:10Z
dc.date.available2013-04-29T19:12:10Z
dc.date.created2013
dc.date.issued2013
dc.identifier.urihttp://hdl.handle.net/10393/24083
dc.identifier.urihttp://dx.doi.org/10.20381/ruor-2974
dc.description.abstractBackground: Adverse birth outcomes present a difficult and chronic challenge in Ontario, in Canada and in developed countries in general. Increasing proportions of preterm births, significant regional disparities and the high cost of treating all adverse birth outcomes have focused attention on explaining them and developing effective treatments. Methods: Birth outcomes and maternal characteristics for approximately 626,000 births, about 90% of births in 2005–2009, were linked to small geographic areas throughout Ontario. For each of four adverse outcomes: late preterm, moderate to very preterm, small for gestation age and still births, proportions of total births were calculated for the full province and for each small geographic area. Geographic hotspots of elevated rates were identified for each of the different adverse birth outcomes using the local Moran’s I statistic. Data for nine known ecologic and individual risk factors were then linked to the areas. Hierarchical regression analysis was used to model each of the outcomes for the full province and for dispersed local areas. The resulting models for the different outcomes were contrasted. Results: Significant geographic hotspots exist for each of the four outcomes. Hotspots for the different outcomes were found to be largely spatially exclusive. For like outcomes, predictive models differed markedly between local areas (i.e. local groups of hotspots) as well as between full-province and local areas. Ecologic level variables played a strong role in all models; the influence of individual level risk factors was consistently modified by ecologic risk factors except for small for gestational births. Conclusions: The finding of significant hotspots for different adverse birth outcomes indicates that certain geographic areas have aetiologies or patterns of predictors sufficient to create significantly elevated levels of particular outcomes. The finding that hotspots for the different adverse outcomes are largely exclusive implies that the aetiologies are specific; i.e., those that are sufficient to create significantly higher levels for one outcome do not also create significantly higher levels of others. The consistently strong role of ecologic level risk factors in modifying individual level risk factors implies that contextual characteristics are an important part of the aetiology of adverse birth outcomes. Differences in local area models suggest the existence of location-specific (rather than universal) aetiologies. The findings support the need for more careful attention to local context when explaining birth outcomes.
dc.language.isoen
dc.publisherUniversité d'Ottawa / University of Ottawa
dc.subjectbirth
dc.subjectoutcomes
dc.subjectadverse
dc.subjectmaternal
dc.subjectcharacteristics
dc.subjectpremature
dc.subjectsmall for gestational age
dc.subjectSGA
dc.subjectstillbirth
dc.subjectspatial cluster
dc.subjectlocal Moran's I
dc.subjecthotspots
dc.subjectlocal area
dc.subjectHierarchical regression analysis
dc.subjectGLIMMIX
dc.subjectsmoked
dc.subjectmorbidity
dc.subjecthealth problem
dc.subjectage
dc.subjectolder age
dc.subjectteenage
dc.subjectecologic
dc.subjectindividual
dc.subjecteducation
dc.subjectincome
dc.subjectAsian
dc.subjecturban
dc.subjectrural
dc.titleAccounting for the Distribution of Adverse Birth Outcomes in Ontario: A Hierarchical Analysis of Provincial and Local Outcomes
dc.typeThesis
dc.faculty.departmentSanté des populations / Population Health
dc.contributor.supervisorMcDowell, Ian
dc.embargo.termsimmediate
dc.degree.namePhD
dc.degree.leveldoctorate
dc.degree.disciplineÉtudes supérieures / Graduate Studies
thesis.degree.namePhD
thesis.degree.levelDoctoral
thesis.degree.disciplineÉtudes supérieures / Graduate Studies
uottawa.departmentSanté des populations / Population Health
CollectionThèses, 2011 - // Theses, 2011 -

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