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. Author manuscript; available in PMC: 2019 May 1.
Published in final edited form as: J Clin Exp Neuropsychol. 2017 Aug 2;40(4):411–422. doi: 10.1080/13803395.2017.1356912

Table 1.

Perceived Cognitive Difficulties, Neuropsychological Performance, Demographic Information, and Clinical Characteristics.

All Participants
n=95
Former Smokers
Without COPD
n=36
Former Smokers
With COPD
n=59
Effect size
(Cohen’s D
or phi)

Demographic and Clinical Variables Mean (SD) (n) % Mean (SD) (n) % Mean (SD) (n) %
Age 68.7 (7.0) 66.1 (6.6)** 70.3 (6.8)** 0.63
Sex (n/% female) (40) 42.1 (16) 44.4 (24) 40.7 0.04
Education 14.2 (2.2) 14.6 (2.2) 13.9 (2.2) 0.32
Estimated Premorbid IQ (WRAT-IV) 101.0 (7.8) 99.4 (9.1) 101.9 (6.8) 0.31
Smoking history (pack-years) 51.3 (33.1) 37.4 (22.3)*** 59.8 (35.8)*** 0.75
Depression and Anxiety (HADS) 6.6 (5.0) 5.3 (3.8)* 7.4 (5.5)* 0.44
Post-Bronchodilator Spirometry
   FEV1/FVC(%)
   FEV1 % Predicted 61.4 (17.0) 78.3 (5.3)*** 51.1 (12.8)*** 2.78
Asthma 66.6 (28.2) 92.7 (17.8)*** 50.7 (20.4)*** 2.19
Diabetes Mellitus Type 2 (24) 25.3 (4) 11.1* (20) 33.9* 0.25
Sleep Apnea (11) 11.6 (5) 13.9 (6) 10.2 0.06
Hypertension (25) 26.3 (13) 36.1 (12) 20.3 0.17
Hypercholesterolemia (4) 4.2 (3) 8.3 (1) 1.7 0.16
(54) 56.8 (20) 55.6 (34) 57.6 0.02

Neuropsychological Test Performance
Memory Recall (T-score) 49.1 (8.5) 51.0 (8.9) 47.9 (8.1) 0.36
Executive functioning/ 48.7 (6.5) 50.8 (6.4)* 47.4 (6.3)* 0.54
Processing-speed (T-score)
Language (T-score) 52.2 (7.0) 53.6 (7.6) 51.3 (6.6) 0.32
Visuospatial Functioning (T-score) 52.0 (6.2) 51.6 (6.9) 52.2 (5.7) 0.09

Cognitive Difficulties Scale (CDS)
CDS Total Score 36.5 (18.0) 35.9 (17.3) 36.9 (18.5) 0.06
CDS Attention/Concentration 11.6 (6.3) 11.4 (6.1) 11.7 (6.4) 0.05
CDS Praxis (n/% with no (37) 38.9 (17) 47.2 (20) 33.9 0.34
reported impairment)
CDS Delayed Recall (n/% with (23) 24.2 (6) 16.7 (17) 28.8 0.23
no reported impairment)
CDS Orientation for Persons 5.2 (2.5) 4.9 (3.0) 5.4 (2.2) 0.19
CDS Temporal Orientation 2.1 (1.5) 2.1 (1.4) 2.1 (1.6) 0.00
CDS Prospective Memory 3.0 (1.5) 3.2 (1.3) 2.9 (1.5) 0.21

Medications
Inhaled Corticosteroid (42) 44.2 (4) 11.1*** (38) 64.4*** 0.52
Inhaled Short Acting Beta (29) 30.5 (3) 8.3** (26) 44.1** 0.38
Agonist
Long Acting Beta Agonist (33) 34.7 (1) 2.8*** (32) 54.2*** 0.52
Statin (48) 50.5 (16) 44.4 (32) 54.2 0.10
Antidepressant (19) 20.0 (7) 19.4 (12) 20.3 0.08
ACE Inhibitor (22) 23.2 (6) 16.7 (16) 27.1 0.13
Beta Blocker (18) 18.9 (6) 16.7 (12) 20.3 0.05
Hormone-Replacement Therapy (11) 11.6 (5) 14.0 (6) 10.2 0.24
*

p<.05,

**

p<.01,

***

p<.001;

CDS Praxis and Delayed Recall Scales were considered dichotomously in all analyses due to skewed distributions

Note: T-Scores for each cognitive domain are age-corrected average values for the tests in that domain. T-scores have a mean of 50 and a standard deviation of 10. The CDS scores have the following items and ranges: Total Score (39 items): 0–156; Attention/Concentration (11 items): 0–44; Praxis (4 items): 0–16; Delayed Recall (3 items): 0–12; Orientation for Persons (4 items): 0–16; Temporal Orientation (2 items): 0–8; CDS Prospective Memory (2 items): 0–8. Regarding effect sizes, Cohen’s D was used for continuous variables and phi was used for dichotomous variables.