O2‐05‐03: Birth Cohort Effects in Memory Function and Practice Effects From Epidemiological Studies of Cognitive Impairment and Dementia

course.Methods:Our objective was to present estimates of the prevalence and incidence of dementia cases across EHRs available through EMIF from six sites in five European countries over a nine-year observation period. All six EHR databases (three primary care, three secondary care) initiated data collection either on or before 2002. Diagnosed dementia was ascertained by consensus harmonization of the various clinical/diagnostic coding systems employed. The data sources were described in terms of numbers of dementia cases and person years of EHR data before and after the first diagnosis. Annual incidences and period prevalences of dementia by age and gender were calculated for each database. Results: The total number of cases across the six databases from 2004-2012 was 138,625, and the data coverage for people aged 50 years and over during this period was 38,000,000 person years.There was reasonable consistency across databases in age-specific prevalence and incidence of cases, both of which were around 3050% lower than published estimates from surveys or cohort studies carried out in community samples. Age-associated increases in prevalence and incidencewere comparable to those seen in community samples, although with a leveling off in oldest age groups. There were modest increases in prevalences of dementia diagnosis across the nine years analysed but stable incidence rates. Female:male ratios of prevalence and incidence were stable over time. A modest female excess was evident in older age groups for dementia diagnosis prevalence but not for incidence. Conclusions:The EMIF initiative has brought together EHR data on unprecedented numbers of people with dementia. This creates potentially transformative opportunities for novel research, although it is important that study designs are tailored to take into account the recognised under-diagnosis of dementia, as well as the generic strengths, limitations and applicability of EHR data resources. O2-05-03 BIRTH COHORT EFFECTS IN MEMORY FUNCTION AND PRACTICE EFFECTS FROM EPIDEMIOLOGICAL STUDIES OF COGNITIVE IMPAIRMENTAND DEMENTIA Hiroko H. Dodge, Jian Zhu, Tiffany F. Hughes, Beth E. Snitz, Chung-Chou H. Chang, Mary Ganguli, Oregon Health & Science University, Portland, OR, USA; 2 University of Michigan, Ann Arbor, MI, USA; Oregon Center for Aging & Technology (ORCATECH), Portland, OR, USA; University of Michigan School of Public Health, Ann Arbor, MI, USA; 5 Youngstown State University, Youngstown, OH, USA; 6 University of Pittsburgh, Pittsburgh, PA, USA; 7 University of Pittsburgh Graduate School of Public Health, Pittsburgh, PA, USA; University of Pittsburgh School of Medicine, Pittsburgh, PA, USA. Contact e-mail: snitzbe@upmc.edu