Sociodemographic Characteristics and Physical Activity in Patients with COPD: A 3-Month Cohort Study

Figures & data

Table 1. Baseline characteristics of study participants.

	N = 35
	N (%) or mean (±SD)
Demographics/Lifestyle
Age, mean (SD)	66.5	±8.5
Male sex	33	94.3
Race, White	32	91.4
Income > $20,000	18	51.4
Employed currently	3	8.6
Education, college	29	82.9
Unhealthy alcohol use	10	28.6
Enrollment period May–Sept	22	62.9
Live with others	20	57.1
Living as a couple	11	31.4
Body Mass Index, mean (SD)	29.1	±5.5
COPD severity
FEV1 % predicted, mean (SD)	44.9	±17.2
FEV1 % predicted, by severity category
50–80% (Moderate)	12	34.3
30–49% (Severe)	15	42.9
0–29% (Very severe)	8	22.9
mMRC dyspnea scale,^a mean (SD)	2.3	±0.9
0–1	7	20.0
2	10	28.6
3	18	51.4
COPD treatment
Long-acting beta-agonists, inhaled	24	68.6
Long-acting anticholinergic, inhaled	18	51.4
Inhaled corticosteroids, inhaled	21	60.0
Methylxanthine use, oral	2	5.7
Chronic corticosteroid use, oral	7	20.0
Home oxygen therapy	17	48.6
Completed pulmonary rehabilitation	10	28.6
Comorbid illness
Coronary artery disease	11	31.4
Heart Failure	3	8.6
Peripheral artery disease	4	11.4
Osteoarthritis	10	28.6
Depression	16	45.7
Anxiety	12	34.3
Post-traumatic stress disorder	11	31.4

SD = standard deviation; FEV₁ = Forced expiratory volume in 1 s; mMRC = modified medical research council.

^a Patients with mMRC = 4 were excluded from the study.

Table 2. Daily activities reported by participants on the Physical Activity Checklist (PAC).

	Days performed (range 4–8 days)
	≥One day		>50% of days		Proportion^a
Type of physical activity	n	%	n	%	Mean	SD
Travel in a car, bus, or train	27	(96.4)	16	(57.1)	0.59	(0.30)
Walk more than 5 min at a time	26	(92.9)	21	(75.0)	0.76	(0.26)
Prepare your own meal	25	(89.3)	20	(71.4)	0.79	(0.28)
Wash and fold laundry, sweep floors, make bed	24	(85.7)	12	(42.9)	0.56	(0.32)
Pick up mail from the mailbox	23	(82.1)	15	(53.6)	0.60	(0.24)
Visit with relatives or friends	22	(78.6)	9	(32.1)	0.51	(0.29)
Perform an errand (post office, bank, dry cleaner)	21	(75.0)	6	(21.4)	0.44	(0.25)
Walk in a grocery store	20	(71.4)	6	(21.4)	0.48	(0.30)
Unload groceries from car and carry them into home	19	(67.9)	6	(21.4)	0.45	(0.29)
Walk in a mall or store	13	(46.4)	1	(3.6)	0.27	(0.15)
Climb up stairs	12	(42.9)	9	(32.1)	0.75	(0.34)
Go to a medical appointment	9	(32.1)	2	(7.1)	0.33	(0.24)
Dig in yard or garden, chop wood, or shovel snow	8	(28.6)	1	(3.6)	0.29	(0.21)
Exercise at a gym (swim, bike, treadmill, weights)	6	(21.4)	3	(10.7)	0.50	(0.22)
Exercise at home (bike, treadmill, weights)	6	(21.4)	3	(10.7)	0.52	(0.28)

Two activities from the original PAC are not included because they did not apply to all participants: spending time with grandchildren and walking the dog.

^a Proportion of days the participant performed the activity from total number of days the PAC was completed; calculated only for participants who engaged in the activity.

Table 3. Change in measures of physical activity, and dyspnea, over the 3-month study period.

	Baseline (N = 35)		Month 1 (N = 35)		Month 2 (N = 34)		Month 3 (N = 34)
	Mean	SD	Mean	SD	Mean	SD	Mean	SD	p-value
Outcomes
PASE score	100.2	(48.4)	96.0	(62.1)	83.9	(58.1)	82.0	(53.7)	.013
Average daily steps^a	2483	(2141)	2259	(1737)	–	–	1897	(1500)	.038
SOBQ dyspnea score	52.0	(21.5)	57.9	(23.1)	54.5	(23.3)	52.7	(23.3)	.057

PASE = Physical activity scale for the elderly (higher score, better health); Average daily steps = average number of steps per day over 7-day period measured by pedometer; SOBQ = UCSD Shortness of Breath Questionnaire (higher score, worse health).

^aN = 32 at baseline, N = 30 at Month 1, N = 32 at Month 3.

Table 4. Association between individual sociodemographic variables and two physical activity outcomes, after adjusting for study month.

	PASE score^a		Average daily steps^b
Variables^c	ß	p-value	ß	p-value
Age, year	−0.5	0.66	−74	0.03
Male	13.9	0.71	−859	0.50
Race, White	−74.7	0.01	−969	0.35
Income > $20,000	14.3	0.40	224	0.70
Employed, currently	−2.9	0.92	−348	0.74
Education, college	20.8	0.36	193	0.80
Unhealthy alcohol use	14.7	0.44	443	0.49
Enrollment period May–Sept	−3.5	0.84	−794	0.18
Lives with others	40.0	0.02	1092	0.06
Lives as a couple	27.7	0.13	227	0.72
Walks a dog	10.1	0.58	498	0.42

PASE = Physical activity scale for the elderly (higher score, better health); Average daily steps = average number of steps/day over 7-day period measured by pedometer.

^aAdjusted for study month (baseline, month 1, month 2, month 3).

^bAdjusted for study month (baseline, month 1, month3); steps/day not measured at month 2.

^cEach row is a separate repeated measures model with the individual sociodemographic variable to predict the PASE score and the average daily steps after adjusting for study month.

Table 5. Multivariable association between sociodemographic variables and two physical activity outcomes.

(A) PA outcome: PASE score
	Model 1^a		Model 2^a
	ß	p-value	ß	p-value
Lives with others	37.2	<0.0001	46.4	<0.0001
Race, White	−70.7	<0.0001	−55.4	<0.0001
Age, per year			−0.3	0.44
Study month
Month 0	Ref	Ref	Ref	Ref
Month 1	−4.2	0.72	−4.2	0.67
Month 2	−17.1	0.15	−16.7	0.09
Month 3	−18.9	0.11	−18.5	0.06
FEV1 % predicted
<30%			Ref	Ref
30–49%			−10.1	0.29
50–79%			−8.5	0.40
mMRC dyspnea scale^b
0–1				Ref
2			−37.7	0.0007
3			−71.4	<0.0001
(B) PA outcome: Average daily steps
	Model 1^a		Model 2^a
	ß	p-value	ß	p-value
Lives with others	798	0.03	942	0.008
Age, per year	−68	0.001	−77	0.0003
Study month
Month 0	Ref	Ref	Ref	Ref
Month 1	−209	0.62	−156	0.69
Month 3	−573	0.17	−537	0.17
FEV1 % predicted
<30%			Ref	Ref
30–49%			−203	0.64
50–79%			663	0.14
mMRC dyspnea scale^b
0–1			Ref	Ref
2			646	0.18
3			−592	0.18

PASE = Physical activity scale for the elderly (higher score, better health); Average daily steps = average number of steps/day over 7-day period measured by pedometer; FEV₁ = forced expiratory volume in one second (higher score, better health); mMRC = modified Medical Research Council dyspnea scale (higher score, worse health).

^aModel 1: Multivariable model adjusted for study month plus the variables associated with physical activity (p < 0.10) in Table 4. Model 2: Multivariable model adjusted for the variables in model 1 plus COPD severity variables: Age, FEV₁ % predicted and mMRC dyspnea scale.

^bPatients with a mMRC score of 4 (too dyspneic to leave the house or breathless when dressing) were excluded from this study.