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Epidemiology of dementia: prevalence and incidence estimates using validated electronic health records from primary care

Authors Ponjoan A, Garre-Olmo J, Blanch J, Fages E, Alves-Cabratosa L, Martí-Lluch R, Comas-Cufí M, Parramon D, Garcia-Gil M, Ramos R

Received 5 September 2018

Accepted for publication 20 December 2018

Published 4 March 2019 Volume 2019:11 Pages 217—228


Checked for plagiarism Yes

Review by Single anonymous peer review

Peer reviewer comments 2

Editor who approved publication: Professor Irene Petersen

Anna Ponjoan,1–3 Josep Garre-Olmo,2 Jordi Blanch,1 Ester Fages,1 Lia Alves-Cabratosa,1 Ruth Martí-Lluch,1–3 Marc Comas-Cufí,1 Dídac Parramon,1,4 María Garcia-Gil,1 Rafel Ramos1,5

1Vascular Health Research Group (ISV-Girona), Jordi Gol Institute for Primary Care Research (IDIAPJGol), Barcelona, Catalonia, Spain; 2Girona Biomedical Research Institute (IDIBGI), Girona, Catalonia, Spain; 3Santa Clara Primary Care Health Center, Catalan Health Institute, Girona, Catalonia, Spain; 4Autonomous University of Barcelona, Bellaterra (Cerdanyola del Vallès), Catalonia, Spain; 5Department of Medical Sciences, School of Medicine, Campus Salut, University of Girona, Girona, Catalonia, Spain

Purpose: Updated estimates of incidence and prevalence of dementia are crucial to ensure adequate public health policy. However, most of the epidemiological studies in the population in Spain were conducted before 2010. This study assessed the validity of dementia diagnoses recorded in electronic health records contained in a large primary-care database to determine if they could be used for research purposes. Then, to update the epidemiology of dementia in Catalonia (Spain), we estimated crude and standardized prevalence and incidence rates of dementia in Catalonia in 2016.
Methods: The System for the Development of Research in Primary Care (SIDIAP) database contains anonymized information for >80% of the Catalan population. Validity of dementia codes in SIDIAP was assessed in patients at least 40 years old by asking general practitioners for additional evidence to support the diagnosis. Crude and standardized incidence and prevalence (95% CI) in people aged ≥65 years were estimated assuming a Poisson distribution.
Results: The positive predictive value of dementia diagnoses recorded in SIDIAP was estimated as 91.0% (95% CI 87.5%–94.5%). Age- and sex-standardized incidence and prevalence of dementia were 8.6/1,000 person-years (95% CI 8.0–9.3) and 5.1% (95% CI 4.5%–5.7%), respectively.
Conclusion: SIDIAP contains valid dementia records. We observed incidence and prevalence estimations similar to recent face-to-face studies conducted in Spain and higher than studies using electronic health data from other European populations.

Keywords: family physician, accuracy, quality, positive predictive value, electronic medical record, real-world data

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