title: Cognitive Impairment in Chronic Obstructive Pulmonary Disease and Chronic Heart Failure: A Systematic Review and Meta-analysis of Observational Studies.
abstract: BACKGROUND
  Cognitive impairment is common in people living with chronic obstructive pulmonary disease (COPD) and chronic heart failure (CHF); however, accurate estimates of prevalence are lacking. To date, there are no meta-analyses that have specifically investigated prevalence of mild cognitive impairment (MCI) in this particular population. Our aim was to undertake a systematic review and apply meta-analytic methods to estimate the prevalence of MCI and any cognitive impairment (ACI) in people with COPD and CHF.
  
  
  METHODS
  We identified relevant studies for COPD and CHF by searching the published literature from inception to February 2016 using the MEDLINE and Web of Science databases. Studies were included if they documented the prevalence of MCI and/or cognitive impairment for COPD and CHF patients without dementia.
  
  
  RESULTS
  Seventeen studies including people with CHF (n = 29,456) and 14 studies including people with COPD (n = 23,116) were included. The pooled mean age for COPD was 66.3 years and for CHF, 75.6 years. The pooled prevalence of MCI in the COPD was 25% (95% CI: 23%, 42%) and ACI, 32% (95% CI: 18%, 38%). Correspondingly, the pooled prevalence of MCI in those with CHF was 32% (95% CI: 22%, 43%) and ACI, 31% (95% CI: 23%, 40%).
  
  
  CONCLUSIONS
  One in 4 people with COPD and 1 in 3 people with CHF had MCI, respectively. The overall prevalence of ACI for COPD was 32% and for CHF, 31%. Future work should consider ways of detecting, managing, or improving cognitive function and other cognition-related outcomes in this group of people.
authors.affiliation: Manchester Metropolitan University, Manchester, United Kingdom. Electronic address: A.yohannes@mmu.ac.uk.
authors.forename: Abebaw M
authors.initials: AM
authors.lastname: Yohannes
authors.affiliation: University of British Columbia, Vancouver, Canada.
authors.forename: W
authors.initials: W
authors.lastname: Chen
authors.affiliation: McGill University, Montreal, Canada.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Moga
authors.affiliation: The University of Manchester, Manchester, United Kingdom.
authors.forename: I
authors.initials: I
authors.lastname: Leroi
authors.affiliation: The University of Auckland and Waitemata District Health Board, Auckland, New Zealand.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Connolly
mesh_terms: D060825:Cognitive Dysfunction / Q000453:epidemiology*; D015897:Comorbidity; D016208:Databases, Factual; D003704:Dementia; D005260:Female; D006333:Heart Failure; D006801:Humans; D008297:Male; D015995:Prevalence; D029424:Pulmonary Disease, Chronic Obstructive
keywords: CHF; COPD; dementia; mild cognitive impairment; prevalence