title: Identification of Physician-Diagnosed Alzheimer's Disease and Related Dementias in Population-Based Administrative Data: A Validation Study Using Family Physicians' Electronic Medical Records.
abstract: Population-based surveillance of Alzheimer's and related dementias (AD-RD) incidence and prevalence is important for chronic disease management and health system capacity planning. Algorithms based on health administrative data have been successfully developed for many chronic conditions. The increasing use of electronic medical records (EMRs) by family physicians (FPs) provides a novel reference standard by which to evaluate these algorithms as FPs are the first point of contact and providers of ongoing medical care for persons with AD-RD.
  
  
  
  We used FP EMR data as the reference standard to evaluate the accuracy of population-based health administrative data in identifying older adults with AD-RD over time.
  
  
  
  This retrospective chart abstraction study used a random sample of EMRs for 3,404 adults over 65 years of age from 83 community-based FPs in Ontario, Canada. AD-RD patients identified in the EMR were used as the reference standard against which algorithms identifying cases of AD-RD in administrative databases were compared.
  
  
  
  The highest performing algorithm was "one hospitalization code OR (three physician claims codes at least 30 days apart in a two year period) OR a prescription filled for an AD-RD specific medication" with sensitivity 79.3% (confidence interval (CI) 72.9-85.8%), specificity 99.1% (CI 98.8-99.4%), positive predictive value 80.4% (CI 74.0-86.8%), and negative predictive value 99.0% (CI 98.7-99.4%). This resulted in an age- and sex-adjusted incidence of 18.1 per 1,000 persons and adjusted prevalence of 72.0 per 1,000 persons in 2010/11.
  
  
  
  Algorithms developed from health administrative data are sensitive and specific for identifying older adults with AD-RD.
authors: Department of Family and Community Medicine, University of Toronto, Toronto, ON, Canada.|Institute for Clinical Evaluative Sciences, Toronto, ON, Canada.|Sunnybrook Academic Family Health Team, Toronto, ON, Canada.
authors: R Liisa
authors: RL
authors: Jaakkimainen
authors: Institute for Clinical Evaluative Sciences, Toronto, ON, Canada.
authors: Susan E
authors: SE
authors: Bronskill
authors: Department of Family and Community Medicine, University of Toronto, Toronto, ON, Canada.|Primary Care Research Unit, Sunnybrook Health Sciences Centre, Toronto, ON, Canada.
authors: Mary C
authors: MC
authors: Tierney
authors: Division of Geriatric Psychiatry, Sunnybrook Health Sciences Centre, Toronto, ON, Canada.
authors: Nathan
authors: N
authors: Herrmann
authors: Performance Management, Cancer Screening, Cancer Care Ontario, Toronto, ON, Canada.
authors: Diane
authors: D
authors: Green
authors: Institute for Clinical Evaluative Sciences, Toronto, ON, Canada.
authors: Jacqueline
authors: J
authors: Young
authors: Department of Family and Community Medicine, University of Toronto, Toronto, ON, Canada.|Women's College Hospital, Toronto, ON, Canada.
authors: Noah
authors: N
authors: Ivers
authors: Department of Family and Community Medicine, University of Toronto, Toronto, ON, Canada.|Scarborough Hospital, Toronto, ON, Canada.
authors: Debra
authors: D
authors: Butt
authors: Sunnybrook Academic Family Health Team, Toronto, ON, Canada.|McGill University Health Centre, Montreal, QC, Canada.
authors: Jessica
authors: J
authors: Widdifield
authors: Department of Family and Community Medicine, University of Toronto, Toronto, ON, Canada.|Sunnybrook Academic Family Health Team, Toronto, ON, Canada.|Toronto Western Family Health Team, Toronto, ON, Canada.
authors: Karen
authors: K
authors: Tu
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D003704:Dementia / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology*; D057286:Electronic Health Records; D062665:Epidemiological Monitoring; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D018697:Nootropic Agents / Q000627:therapeutic use; D009864:Ontario / Q000453:epidemiology; D010821:Physicians, Family; D015995:Prevalence; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012737:Sex Factors
chemical_list: D018697:Nootropic Agents
keywords: Dementia; electronic medical records; family physician; health administrative algorithm