Subjective cognitive complaints and neuropsychological performance in former smokers with and without chronic obstructive pulmonary disease

ABSTRACT

Objective: This study examined the association of perceived cognitive difficulties with objective cognitive performance in former smokers. We hypothesized that greater perceived cognitive difficulties would be associated with poorer performance on objective executive and memory tasks.

Method: Participants were 95 former smokers recruited from the COPDGene study. They completed questionnaires (including the Cognitive Difficulties Scale [CDS] and the Hospital Anxiety and Depression Scale [HADS]), neuropsychological assessment, and pulmonary function testing. Pearson correlations and t-tests were conducted to examine the bivariate association of the CDS (total score and subscales for attention/concentration, praxis, delayed recall, orientation for persons, temporal orientation, and prospective memory) with each domain of objective cognitive functioning (memory recall, executive functioning/processing speed, visuospatial processing, and language). Simultaneous multiple linear regression was used to further examine all statistically significant bivariate associations. The following covariates were included in all regression models: age, sex, pack-years, premorbid functioning (WRAT-IV Reading), HADS total score, and chronic obstructive pulmonary disease (COPD) status (yes/no based on GOLD criteria).

Results: In regression models, greater perceived cognitive difficulties overall (using CDS total score) were associated with poorer performance on executive functioning/processing speed tasks (b = −0.07, SE = 0.03, p = .037). Greater perceived cognitive difficulties on the CDS praxis subscale were associated with poorer performance on executive functioning/processing speed tasks (b = −3.65, SE = 1.25, p = .005), memory recall tasks (b = −4.60, SE = 1.75, p = .010), and language tasks (b = −3.89, SE = 1.39, p = .006).

Conclusions: Clinicians should be aware that cognitive complaints may be indicative of problems with the executive functioning/processing speed and memory of former smokers with and without COPD.

KEYWORDS:

• Cognition
• Cognitive Difficulties Scale
• lung disease
• neuropsychology
• self-report

Acknowledgments

We thank Ann Depew and Christina Schnell for assistance with participant recruitment and Trudi Madigan, Ronnie Calzada, Steven Belcher, and James Thorpe for assistance with data collection, James Murphy for assistance with study design, and Anne Hunting, Lyndsay Lev, and Anna Croghan for administrative support. Study data were collected and managed using REDCap electronic data capture tools hosted at the University of Colorado. REDCap (Research Electronic Data Capture) is a secure, web-based application designed to support data capture for research studies.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Institutes of Health (NIH) [Grant K23 HL095658, R01 HL089897, R01 HL089856], and the NIH/NCATS Colorado CTSI [Grant No. UL1 TR001082]. Contents are the authors’ sole responsibility and do not necessarily represent official NIH views. The COPDGene study [NCT00608764] is also supported by the COPD Foundation through contributions made to an Industry Advisory Board comprised of AstraZeneca, Boehringer-Ingelheim, Novartis, Pfizer, GlaxoSmithKline, Siemens, and Sunovion.