Abstract
Objective: There is increasing interest in the use of administrative data for surveillance and research in Australia. The purpose of the present study was to evaluate the usefulness of such data for the surveillance of mood and anxiety disorder using databases from the following Canadian provinces: British Columbia, Ontario, Quebec and Nova Scotia.
Method: A population-based record-linkage analysis was done using data from physician billings and hospital discharge abstracts, and community-based clinics using a case definition of ICD-9 diagnoses of 296.0–296.9, 311.0, and 300.0–300.9.
Results: The prevalence of treated mood and/or anxiety disorder was similar in Nova Scotia, British Columbia, and Ontario at approximately 10%. The prevalence for Quebec was slightly lower at 8%. Findings from the provinces showed consistency across age and sex despite variations in data coding. Women tended to show a higher prevalence overall of mood and anxiety disorder than men. There was considerably more variation, however, when treated anxiety (300.0–300.9) and mood disorders (296.0–296.9, 311.0) were considered separately. Prevalence increased steadily to middle age, declining in the 50s and 60s, and then increased after 70 years of age.
Conclusions: Administrative data can provide a useful, reliable and economical source of information for the surveillance of treated mood and/or anxiety disorder. Due to the lack of specificity, however, in the diagnoses and data capture, it may be difficult to conduct surveillance of mood and anxiety disorders as separate entities. These findings may have implications for the surveillance of mood and anxiety disorders in Australia with the development of a national network for the extraction, linkage and analysis of administrative data.
Acknowledgements
The authors wish to thank Wayne Jones, University of British Columbia for the data from British Columbia. The data from Quebec were made available by Montreal's Agency for Health and Social Services (Agence de la santé et des services sociaux de Montréal) through the Access to Information Agency (Commission d'Accéss à l'Information); we wish particularly to thank Mike Benigeri from the Agency. Ontario data were accessed and analysed through the Institute of Clinical Evaluative Sciences (ICES). ICES is supported in part by a grant from the Ontario Ministry of Health and Long-Term Care. The data from Nova Scotia were made available by the Population Health Research Unit (PHRU) within Dalhousie University's Department of Community Health and Epidemiology. The Province of Nova Scotia supplies the PHRU with complete Medicare and hospital files suitable for research purposes. The opinions, results and conclusions are those of the authors, and no endorsement by any of the relevant data sources or provincial governments is intended, or should be inferred. The Public Health Agency of Canada funded the data extraction and linkage used in this research. Charles Gilbert is employed by the Public Health Agency of Canada.