Associations of cognition with physical functioning and health-related quality of life among COPD patients.
Neurocognitive impairment has been described in COPD patients, but little is known about its relationship with physical functioning and health-related quality of life (HRQL) in this chronically ill patient group.



301 stable COPD patients completed the Trail Making Test (TMT-A: psychomotor speed and TMT-B: executive control); 198 patients completed the Memory Impairment Screen (MIS). Standardization of TMT-A and TMT-B scores to a normative population yielded classifications of normal, borderline, or impaired cognitive status. Using multivariable regression, we examined the relationship between the TMT-A, TMT-B, and MIS with physical functioning (physical activity, 6-min walk test, and grip strength) and health-related quality of life (HRQL) measured with the Chronic Respiratory Questionnaire and the SF-36.



Nearly 30% of patients had either borderline or impaired cognition on the TMT-A or TMT-B. Adjusted models indicated that those with either borderline or impaired cognitive functioning had weaker grip strength (TMT-A borderline: β = -2.9, P < 0.05; TMT-B borderline: β = -3.0, P < 0.05; TMT-B impaired: β = -2.5, P < 0.05) and lower scores on the mental health component summary score (MCS-SF-36 HRQOL) measure (TMT-A impaired: β = -4.7, P < 0.01). No adjusted significant associations were found for other physical functioning measures or the other HRQL measures. Impaired memory showed a significant association only with the MCS scale.



Cognitive function was not associated with most standard indicators of physical function or most measures of HRQL in COPD patients. Both TMT-A and TMT-B were associated with weaker grip strength, and the TMT-A and MIS with poorer mental health.
Department of Health and Human Development, Montana State University, PO Box 173540, Bozeman, MT 59717-3540, USA. Electronic address: mark.schure@montana.edu.
Mark B
MB
Schure
Department of Psychiatry and Behavioral Sciences, School of Medicine, University of Washington, Box 356560, Seattle, WA 98195-6560, USA.
Soo
S
Borson
Kaiser Permanente Southern California, 100 S Los Robies, Pasadena, CA 91101, USA.
Huong Q
HQ
Nguyen
Department of Psychiatry and Behavioral Sciences, School of Medicine, University of Washington, Box 356560, Seattle, WA 98195-6560, USA; Geriatric Research Education and Clinical Center, VA Puget Sound Health Care System, 1660 S. Columbian Way, Seattle, WA 98108, USA.
Emily H
EH
Trittschuh
Department of Psychiatry and Behavioral Sciences, School of Medicine, University of Washington, Box 356560, Seattle, WA 98195-6560, USA; Geriatric Research Education and Clinical Center, VA Puget Sound Health Care System, 1660 S. Columbian Way, Seattle, WA 98108, USA.
Stephen M
SM
Thielke
Office of Nursing Research, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195, USA.
Kenneth C
KC
Pike
University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA; South Texas Veterans Health Care System, 7400 Merton Minter Blvd, San Antonio, TX 78229, USA.
Sandra G
SG
Adams
Health Services Research & Development, Center of Innovation VA Puget Sound Health Care System, 1660 S. Columbian Way, Seattle, WA 98108, USA; Department of Medicine, University of Washington, 1959 NE Pacific St, Seattle, WA 98195, USA.
Vincent S
VS
Fan
D000368:Aged; D060825:Cognitive Dysfunction / Q000150:complications* / Q000453:epidemiology / Q000401:mortality; D015331:Cohort Studies; D003430:Cross-Sectional Studies / Q000379:methods; D015444:Exercise / Q000523:psychology; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D018737:Hand Strength / Q000502:physiology; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D010809:Physical Fitness / Q000523:psychology*; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications* / Q000453:epidemiology / Q000503:physiopathology; D011788:Quality of Life / Q000523:psychology*; D012720:Severity of Illness Index; D000070857:Walk Test / Q000379:methods
Affective symptoms; COPD; Cognition; Motor strength; Physical activity; Physical functioning; Quality of life