Determinants of change in physical activity during moderate-to-severe COPD exacerbation

Figures & data

Figure 1 Flowchart of exclusions and missing cases.

Abbreviation: ED, emergency department.

Table 1 Descriptive characteristics of the sample by admission status

	Hospital admission		P-value
	Yes	No
Age, years	72.6 (9.6)	73.0 (9.7)	0.74
Male, %	1,394 (90.3)	873 (91.8)	0.33
Baseline FEV1, %			≤0.0001
≥50	429 (30.7)	339 (43.1)
30–49	666 (47.7)	342 (43.5)
<30	302 (21.6)	106 (13.5)
Previous HOT/CPAP/NIMV	585 (38.1)	256 (26.9)	≤0.0001
Charlson Comorbidity Index	2.31 (1.6)	2.10 (1.6)	0.002
EQ-5D	0.60 (0.28)	0.64 (0.29)	0.003
Previous admission (year before)	1.0 (1.5)	0.56 (1.1)	≤0.0001
Living arrangements			0.001
Lives alone	204 (12.6)	81 (8.1)
Lives in a residence	38 (2.4)	17 (1.7)
Lives with someone	1,348 (83.6)	888 (89.3)
Other	23 (7.4)	9 (0.9)
Edema (at arrival ED)	299 (21.0)	137 (15.1)	≤0.0001
Dyspnea at rest (at arrival ED)	1,301 (78.5)	461 (50.7)	≤0.0001
Glasgow Coma Scale <15 (at ED arrival)	59 (3.8)	11 (1.1)	0.0003
Baseline physical activity			≤0.0001
1= from bed to chair only	101 (7.2)	56 (6.7)
2= housebound, but walks inside	103 (7.3)	43 (5.1)
3= walks a few hundred meters	363 (25.7)	165 (19.7)
4= walks for errands	409 (29.0)	194 (23.2)
5= usual walker	425 (30.1)	366 (43.8)
6= does some sports	10 (0.7)	12 (1.4)
Physical activity at 24 hours			≤0.0001
1= bedridden	222 (15.6)	31 (3.6)
2= sits	234 (16.5)	44 (5.2)
3= walks just to the bathroom	469 (33.0)	69 (8.1)
4= walks around the room	246 (17.3)	123 (14.5)
5= walks outside of the room with limitations	212 (14.9)	381 (45.0)
6= walks outside of the room without limitations	37 (2.6)	199 (23.5)
Physical activity at 1 week/discharge			≤0.0001
1= bedridden	35 (2.6)	24 (2.9)
2= sits	60 (4.5)	24 (2.9)
3= walks just to the bathroom	114 (8.5)	32 (3.8)
4= walks around the room	227 (17.0)	74 (9.0)
5= walks outside of the room with limitation	628 (46.9)	342 (41.5)
6= walks outside of the room without limitation	274 (20.4)	328 (39.8)
Length of stay (admitted)	7.75 (6.2)	N/A
Death	56 (3.6)	3 (0.3)	≤0.0001

Notes: Summary variables are presented as mean ± standard deviation for quantitative variables, and frequency for discrete variables.

Abbreviations: FEV₁, forced expiratory volume in 1 second; HOT, home oxygen therapy; CPAP, continuous positive airways pressure; N/A, not applicable; NIMV, noninvasive mechanical ventilation; EQ-5D, European Quality of Life-5 Dimensions; ED, emergency department.

Figure 2 Changes in physical activity from ED arrival to follow-up by basal physical activity level and admission status.

Note: Physical activity levels: 1 – I am bedridden; 2 – I sit down; 3 – I walk to the bathroom; 4 – I walk in the room; 5 – I walk outside the room with limitations; and 6 – I can walk outside the room without limitations.
Abbreviation: ED, emergency department.

Table 2 Univariate analysis of predictors of change of physical activity at hospital discharge or 7 days after visiting the ED

	Hospital admission
	Yes		No
	β estimate	P-value	β estimate	P-value
Age	−0.01	≤0.0001	−0.02	≤0.0001
Sex
Men	−0.08	0.48	−0.001	0.99
Women	–	–	–	–
Baseline FEV1, %
≥50	–	–	–	–
30–49	−0.23	0.003	−0.38	≤0.0001
<30	−0.38	≤0.0001	−0.75	≤0.0001
Previous HOT/CPAP/NIMV
No	–	–	–	–
Yes	−0.48	≤0.0001	−0.50	≤0.0001
Charlson Comorbidity Index	−0.08	≤0.0001	−0.06	0.01
Previous admission (year before)	−0.08	≤0.0001	−0.08	0.05
Living arrangements
Lives alone	0.25	0.01	0.28	0.05
Lives in a residence	−0.59	0.002	−1.1	0.0007
Other	−0.43	0.14	−1.03	0.009
Lives with someone	–	–	–	–
Edema (at arrival ED)
No	–	–	–	–
Yes	−0.36	0.001	−0.13	0.10
Dyspnea at rest (at arrival ED)
No	–	–	–	–
Yes	−0.28	0.0003	−0.37	≤0.0001
Glasgow Coma Scale <15 (at arrival ED)
No	–	–	–	–
Yes	−0.65	0.0006	−1.24	0.0008
Baseline physical activity
1= from bed to chair life only	−2.00	≤0.0001	−2.49	≤0.0001
2= housebound, but could walk inside	−1.37	0.0001	−1.36	≤0.0001
3= walks a few hundred meters	−0.85	0.01	−0.66	0.02
4= walks for errands	−0.51	0.14	−0.22	0.46
5= usually walker	−0.24	0.47	−0.002	0.99
6= does some sports	–	–	–	–
Physical activity at 24 hours after ED arrival
1= bedridden	−1.59	≤0.0001	−2.80	≤0.0001
2= sits	−1.22	≤0.0001	−2.21	≤0.0001
3= walks just to the bathroom	−0.79	≤0.0001	−1.26	≤0.0001
4= walks around the room	−0.56	0.005	−0.88	≤0.0001
5= walks outside of the room with limitations	−0.25	0.22	−0.49	≤0.0001
6= walks outside of the room without limitations	–	–	–	–
Length of stay	−0.03	≤0.0001	–	–

Note: Reference categories for each variable were the best situation category for each variable.

Abbreviations: FEV₁, forced expiratory volume in 1 second; HOT, home oxygen therapy; CPAP, continuous positive airways pressure; NIMV, noninvasive mechanical ventilation; ED, emergency department.

Table 3 Change in PA level in admitted patients: multivariate analysis

	β estimate	P-value
Intercept	5.63	<0.0001
Baseline physical activity
From “bed to chair life” or housebound, but walks inside	−0.61	<0.0001
Walks a few hundred meters	−0.16	0.026
Walks for errands or usually walker or does some sports	–	–
Physical activity at 24 hours
1= bedridden	−0.64	0.001
2= sits	−0.54	0.005
3= walks just to the bathroom	−0.36	0.05
4= walks around the room	−0.30	0.11
5= walks outside of the room with limitation	−0.12	0.54
6= walks outside of the room without limitation	–	–
Age	−0.012	<0.0001
EQ-5D	0.95	<0.0001
Home status
Lives alone	0.21	0.015
Lives in a residence	−0.14	0.43
Other	−0.18	0.49
Lives with someone	–	–
Medication
Anticholinergic (used)	0.16	0.03
Anticholinergic (not used)	–	–
Corticosteroids (systemic) used	−0.27	0.0005
Corticosteroids (systemic) not used	–	–
Length of hospital stay	−0.012	0.03

Notes: Model R-square: 0.30, adjusted for participating hospital. Reference categories for each variable were the best case category for each variable. Baseline physical activity categories were reduced to three levels for this model.

Abbreviations: PA, physical activity; EQ-5D, European Quality of Life-5 Dimensions.

Table 4 Change in PA level in ED discharged patients: multivariate analysis

	β estimate	P-value
Intercept	5.95	<0.0001
Baseline PA
From bed to chair life only or housebound, but could walk inside	−1.17	<0.0001
Walks a few hundred meters	−0.32	0.0005
Walks for errands or usually walker or does some sports	–	–
Physical activity at 24 hours
1= bedridden	−2.04	≤0.0001
2= sits	−1.52	≤0.0001
3= walks just to the bathroom	−0.94	≤0.0001
4= walks around the room	−0.68	≤0.0001
5= walks outside of the room with limitation	−0.41	≤0.0001
6= walks outside of the room without limitation	–	–
FEV1, %
<30	−0.23	0.04
30–49	−0.19	0.01
≥50	–	–
Dyspnea at rest at ED arrival
Yes	−0.16	0.03
No	–	–

Notes: Model R-square: 0.43, reference categories for each variable were the best case category for each variable; baseline physical activity categories were reduced to three levels for this model.

Abbreviations: ED, emergency department; PA, physical activity; FEV₁, forced expiratory volume in 1 second.

Table 5 Outcomes by physical activity levels in patients admitted and discharged from ED

Outcomes	Physical activity level						P-value
	1	2	3	4	5	6
Hospital admitted patients
Baseline physical activity
Length of stay	8.9 (5.1)	10.2 (7.7)	8.8 (6.6)	7.5 (5.0)	6.1 (3.8)	5.3 (4.1)	≤0.0001
Death during admission	19 (15.45)	11 (9.17)	9 (2.12)	3 (0.67)	1 (1.25)	1 (0.25)	≤0.0001
Physical activity at 24 hours
Length of stay	9.2 (6.3)	8.9 (5.8)	7.6 (5.7)	7.2 (4.7)	5.8 (3.9)	6.8 (5.6)	≤0.0001
Death during admission	27 (10.55)	7 (2.67)	7 (1.31)	3 (1.06)	0 (0)	0 (0)	≤0.0001
Physical activity at discharge
Readmissions until 2 months	16 (40)	17 (25.37)	38 (29.92)	65 (25.39)	142 (20.40)	41 (15.65)	0.001
ED discharged patients
Physical activity at 1 week
Readmissions until 2 months	11 (40.74)	7 (34.14)	7 (19.44)	22 (26.51)	53 (12.68)	33 (10.61)	≤0.0001

Notes: Summary variables are presented as mean ± standard deviation for quantitative variables, and frequencies and percentage for discrete variables. Baseline physical activity: 1, from bed to chair only; 2, “housebound but I walk inside”; 3, “I walk a few hundred meters outside”; 4, “I walk for errands”; 5, “I regularly walk – walk an itinerary at least 3 days a week”; 6, “I do some kind of sports”. Physical activity at 24 hours, physical activity at discharge, physical activity at 1 week after being discharged from ED: 1, “I am bedridden”; 2, “I sit”; 3, “I walk just to the bathroom”; 4, “I walk in the room”; 5, “I walk outside the room with limitation”; 6, “I can walk outside room without limitations”.

Abbreviation: ED, emergency department.