Mild cognitive impairment in chronic obstructive pulmonary disease and chronic heart failure: A systematic review and meta-analysis

Background: Cognitive impairments are common in patients with chronic obstructive pulmonary disease (COPD) and chronic heart failure (CHF). To date there are no meta- analyses that have investigated the prevalence of mild cognitive impairment (MCI) in patients with COPD and CHF. Aims: To examine the individual study data set using meta-analysis to estimate the prevalence of MCI in patients with COPD and CHF. Methods Data sources: We identified relevant studies for COPD and CHF by searching published literature from inception to February 2016 using the MEDLINE and Web of Science databases. Study selection: Studies were included if they documented the prevalence of MCI and CHF for patients without dementia and employed appropriate screening tool for cognitive impairment. Data extraction and synthesis: 17 studies of CHF patients (n= 29,456) and 14 studies of COPD patients (n= 23, 116) were included for the meta-analysis. Main outcome measures: Prevalence of MCI in patients with COPD and CHF. The pooled prevalence of MCI for patients with COPD was estimated at 24% (95% CI: 12%, 38%). The prevalence of MCI in patients with CHF was 35% (95% CI: 25%, 45%). In the jackknife sensitivity analysis, both pooled estimates did not substantially vary when the meta-analysis was repeated with each included study being excluded one at a time. Conclusions: Approximately, 24% COPD patients and 35% CHF patients respectively had MCI. Studies are needed to examine the efficacy of intervention on MCI.