Ponjoan A, et al. - In this investigation, researchers first evaluated the validity of dementia diagnoses recorded in electronic health records in a large primary-care database to determine whether they could be used for research purposes. Then, they estimated crude and standardized prevalence and incidence rates of dementia in Catalonia (Spain) in 2016 to update the epidemiology of dementia in Catalonia. The database System for the Development of Research in Primary Care (SIDIAP) contains anonymous information for >80% of the Catalan population. In patients at least 40 years of age, the validity of dementia codes in SIDIAP was assessed by requesting additional evidence from general practitioners to support the diagnosis. Assuming a Poisson distribution, crude and standardized incidence and prevalence (95% CI) in people aged ≥65 years were estimated. Data reported that the positive predictive value of dementia diagnoses recorded in SIDIAP was estimated at 91.0%. Findings revealed that diagnoses of dementia recorded in the database of SIDIAP are valid for research purposes. For women and the oldest-old population, age- and sex-standardized prevalence and incidence rates of dementia in 2016 were higher. Similar to recent face-to-face studies carried out in Spain and higher than studies using electronic health data from other European populations, they observed incidence and prevalence estimates.