Influenza Vaccine Effectiveness in the Elderly Based on Administrative Databases: Change in Immunization Habit as a Marker for Bias

• Travis S. Hottes,

  Affiliation Epidemiology Services, BC Centre for Disease Control, Vancouver, British Columbia, Canada

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• Danuta M. Skowronski ,

  * E-mail: danuta.skowronski@bccdc.ca

  Affiliations Epidemiology Services, BC Centre for Disease Control, Vancouver, British Columbia, Canada, School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada

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• Brett Hiebert,

  Affiliation Department of Community Health Sciences, Faculty of Medicine, Manitoba Centre for Health Policy, University of Manitoba, Winnipeg, Manitoba, Canada

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• Naveed Z. Janjua,

  Affiliations Epidemiology Services, BC Centre for Disease Control, Vancouver, British Columbia, Canada, School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada

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• Leslie L. Roos,

  Affiliation Department of Community Health Sciences, Faculty of Medicine, Manitoba Centre for Health Policy, University of Manitoba, Winnipeg, Manitoba, Canada

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• Paul Van Caeseele,

  Affiliation Cadham Provincial Laboratory, Manitoba Health, Winnipeg, Manitoba, Canada

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• Barbara J. Law,

  Affiliation Surveillance and Outbreak Response Division, Centre for Immunization and Respiratory Infectious Diseases, Public Health Agency of Canada, Ottawa, Ontario, Canada

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• Gaston De Serres

  Affiliations Institut national de santé publique du Québec, Québec, Québec, Canada, Department of Social and Preventive Medicine, Université Laval, Québec, Canada

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