title: Risk of dementia and death in patients with atrial fibrillation: A competing risk analysis of a population-based cohort.
abstract: BACKGROUND
  Previous studies have stated that atrial fibrillation (AF) is associated with a higher risk of dementia. However, none have examined the competition between death and incident dementia in patients with AF. We evaluated the risk of incident dementia in patients with AF in comparison to people without this arrhythmia, considering of the competing risk of death.
  
  
  METHODS
  AF and non-AF cohorts were identified using the large administrative database of the Lombardy Region and followed for ten years. Patients with incident dementia were identified if they had an ICD 9 code referring to dementia at hospital discharge or a prescription for any anti-dementia drug. The association of AF with dementia or death was assessed with the multivariable Cox proportional-regression model, sensitivity analysis with a 1:1 propensity score matching and competing-risk analysis.
  
  
  RESULTS
  In 2003 a total of 27,431 patients were hospitalized for AF in the Lombardy Region, while the cohort of non-AF counted 1,600,200 people. AF was associated with a higher risk of dementia (17%) and death (51%) at multivariable Cox analysis. These results were confirmed by the model fitted after propensity score matching. However, competing risk analysis found the association between AF and incident dementia was no longer significant (HR 0.99; 95% CI 0.94-1.04).
  
  
  CONCLUSIONS
  In this real-world population the association between AF and dementia was no longer statistically significant when death was considered a competing risk.
authors.affiliation: Laboratory of Cardiovascular Prevention, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy. Electronic address: irene.marzona@marionegri.it.
authors.forename: Irene
authors.initials: I
authors.lastname: Marzona
authors.affiliation: Laboratory of Cardiovascular Prevention, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy.
authors.forename: Marta
authors.initials: M
authors.lastname: Baviera
authors.affiliation: Laboratory of Cardiovascular Prevention, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy.
authors.forename: Tommaso
authors.initials: T
authors.lastname: Vannini
authors.affiliation: Laboratory of Geriatric Neuropsychiatry, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Tettamanti
authors.affiliation: Quality Assessment of Geriatric Therapies and Services, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Cortesi
authors.affiliation: Laboratory of Geriatric Neuropsychiatry, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy.
authors.forename: Emma
authors.initials: E
authors.lastname: Riva
authors.affiliation: Quality Assessment of Geriatric Therapies and Services, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Nobili
authors.affiliation: Department of Medical and Biological Sciences, University of Udine, Italy.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Marcon
authors.affiliation: Region Health Ministry, Lombardy Region, Milan, Italy.
authors.forename: Ida
authors.initials: I
authors.lastname: Fortino
authors.affiliation: Region Health Ministry, Lombardy Region, Milan, Italy.
authors.forename: Angela
authors.initials: A
authors.lastname: Bortolotti
authors.affiliation: Region Health Ministry, Lombardy Region, Milan, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Merlino
authors.affiliation: Laboratory of Cardiovascular Prevention, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy.
authors.forename: Maria Carla
authors.initials: MC
authors.lastname: Roncaglioni
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000401:mortality*; D015331:Cohort Studies; D003643:Death; D003704:Dementia / Q000175:diagnosis* / Q000401:mortality*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D011159:Population Surveillance / Q000379:methods; D011446:Prospective Studies; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors
keywords: Atrial fibrillation; Competing risk analysis; Death; Incident dementia