Introduction
Methods
Subjects
Measurements
Physical capacity
Physical activity
PC-PA quadrant concept
Respiratory variables
Blood gas analysis
COPD-specific health status
Comorbidities and survival
Exacerbation history
Data analysis and statistics
Results
Study participants
N = 283 | |
---|---|
Age, y | 63 (58/68) |
Male / Female, N | 184 / 99 |
BMI, kg/m2 | 25.8 (22.4/28.7) |
Waist / Hip ratio | 0.97 (0.91/1.03) |
Smoker / Former smoker, N (%) | 67 (24) / 207 (73) |
Pack years, N | 40 (30/60) |
mMRC score | 2 (1/2) |
CAT score | 15 (11/20) |
Anxiety score | 4 (2/8) |
Depression score | 4 (2/7) |
GOLD, N (%) | |
I | 25 (9) |
II | 92 (33) |
III | 103 (36) |
IV | 63 (22) |
COPD Risk Group, N (%) | |
A | 48 (17) |
B | 192 (68) |
C | 9 (3) |
D | 34 (12) |
FEV1, % pred. | 44 (31/64) |
RV/TLC, % | 55.6 (11.7) |
TLco, ml/mmHg/min | 47 (35/68) |
PaO2, kPa | 9.04 (8.21/10.13) |
PaCO2, kPa | 5.03 (4.63/5.45) |
SaO2, % | 94.7 (93.0/96.0) |
Number of comorbidities, N | 3 (1/4) |
Number of exacerbations in the previous year, N | 1 (0/1) |
Number of severe exacerbations in the previous year, N | 0 (0/0) |
Frequent exacerbator, N (%) | 68 (24) |
Survival time, days | 2094 (1420/2483) |
Retired person, N (%) | 191 (68) |
6MWD, m | 418.3 (125.7) |
6MWD, % pred. | 79.4 (23.1) |
SpO2 after 6MWT, % | 90 (84/95) |
Steps per day, N | 4421 (2522/6863) |
PC-PA quadrants
Differences in clinical characteristics in PC-PA quadrants
“Can’t do, don’t do” N = 85 | “Can do, don’t do” N = 81 | “Can’t do, do do” N = 13 | “Can do, do do” N = 104 | Overall p-value | |
---|---|---|---|---|---|
Age, y | 64 (60/69) | 64 (58/67) | 56 (53/60)*† | 64 (58/68)‡ | 0.007 |
Male, N (%) | 63 (74) | 51 (63) | 7 (54) | 63 (61) | 0.180 |
BMI, kg/m2 | 24.9 (21.1/28.1) | 26.6 (22.8/29.4) | 24.0 (22.6/25.8) | 26.7 (22.6/29.2) | 0.110 |
Waist/Hip ratio | 0.98 (0.90/1.05) | 0.98 (0.93/1.02) | 0.93 (0.90/1.02) | 0.96 (0.89/1.01) | 0.250 |
Smoker, N (%) | 11 (13) | 25 (31)* | 2 (15) | 29 (28)* | 0.026 |
mMRC score | 3 (2/3) | 1 (1/2)* | 2 (1/3) | 1 (1/2)* †‡ | < 0.001 |
CAT score | 18 (14/23) | 14 (10/18)* | 19 (13/22) | 13 (8/19)* | < 0.001 |
Anxiety score | 5 (3/8) | 3 (2/6) | 7 (5/9) | 4.5 (2.0/8.0) | 0.080 |
Depression score | 6 (4/8) | 4 (2/6)* | 5 (2/8) | 3.5 (1.0/6.0)* | < 0.001 |
GOLD, N (%) | < 0.001 | ||||
I | 2 (2) | 6 (7) | 0 (0) | 17 (16)* | |
II | 11 (13) | 27 (33)* | 6 (46)* | 48 (46)* | |
III | 35 (41) | 36 (44) | 3 (23) | 29 (28)† | |
IV | 37 (44) | 12 (15)* | 4 (31) | 10 (10)*‡ | |
COPD Risk Group, N (%) | < 0.001 | ||||
A | 4 (5) | 16 (20)* | 1 (8) | 27 (26)* | |
B | 68 (80) | 54 (67) | 10 (77) | 60 (58)* | |
C | 1 (1) | 0 (0) | 0 (0) | 8 (8)*† | |
D | 12 (14) | 11 (14) | 2 (15) | 9 (9) | |
FEV1, % pred. | 31 (25/43) | 45 (34/65)* | 41 (29/56) | 58 (40.5/75.0)*† | < 0.001 |
RV/TLC, % | 63 (57/68) | 55 (45/65)* | 55 (46/62) | 52 (43/59)* | < 0.001 |
TLco, % pred. | 36 (28/45) | 47 (36/64)* | 43 (34/48) | 63 (46/78)*†‡ | < 0.001 |
PaO2, kPa | 8.6 (7.6/9.5) | 9.0 (8.4/10.1) | 9.3 (8.5/9.6) | 9.6 (8.8/10.5)* | < 0.001 |
PaCO2, kPa | 5.2 (4.7/5.7) | 5.0 (4.5/5.3)* | 5.0 (4.7/5.2) | 4.9 (4.6/5.4) | 0.047 |
SaO2, % | 93.7 (91.2/95.3) | 94.8 (93.3/96.0) | 94.8 (94.5/96.0) | 95.2 (93.7/96.5)* | 0.007 |
Number of comorbidities, N | 3 (2/5) | 3 (2/5) | 2 (1/2)*† | 2 (1.0/3.5)*† | < 0.001 |
Exacerbations in the previous year, N | 1 (0/2) | 0 (0/1) | 1 (0/2) | 0 (0/1)*‡ | < 0.001 |
Severe exacerbations in the previous year, N | 0 (0/1) | 0 (0/0)* | 0 (0/0) | 0 (0/0)* | 0.006 |
Frequent exacerbator, N (%) | 28 (33) | 20 (25) | 6 (46) | 14 (14)*‡ | 0.004 |
Survival time, days (N = 214) | 1550 (836/2268)a | 2115 (1599/2394)b | 2390 (1799/3019)c | 2279 (1944/2839)d*† | < 0.001 |
Retired person, N (%) | 64 (76) | 56 (70) | 7 (54) | 64 (62) | 0.130 |
6MWD, m | 300 (252/349) | 450 (390/510)* | 360 (300/375)† | 495 (444/562)*‡ | < 0.001 |
6MWD, % pred. | 57 (47/65) | 87 (77/95)* | 61 (56/65)† | 96 (95/107)*‡ | < 0.001 |
SpO2 after 6MWT, % | 87 (81/92) | 90 (85/93)* | 91 (87/95) | 92 (87/95)* | < 0.001 |
Steps per day, N | 2388 (1329/3357) | 3284 (2113/3864) | 6590 (6007/9258)*† | 7553 (5876/9819)*† | < 0.001 |
“Can’t do, don’t do” vs “Can do, don’t do” | “Can’t do, don’t do” vs “Can’t do, do do” | “Can’t do, don’t do” vs “Can do, do do” | “Can do, don’t do” vs “Can’t do, do do” | “Can do, don’t do” vs “Can do, do do” | “Can’t do, do do” vs “Can do, do do” | |
---|---|---|---|---|---|---|
Age, y | −1 (− 3/2) | −8 (− 11/− 4)* | 1 (− 3/1) | −7 (− 10/− 4)* | 0 (− 2/2) | 7 (3/10)* |
mMRC score, N | − 1 (− 1/− 1)* | 0 (− 1/0) | − 1 (− 2/− 1)* | 1 (0/1) | 0 (− 1/0)* | − 1 (− 2/0)* |
CAT score, N | − 4.3 (−6.1/− 2.4)* | −0.14 (− 4.0/3.7) | −4.6 (− 6.7/− 2.6)* | 4.1 (0.6/7.6) | −0.4 (− 2.4/1.6) | −4.5 (− 8.9/− 0.1) |
Depression score, N | −2 (− 3/− 1)* | −1 (− 3/2) | − 2 (− 3/− 1)* | 1 (−1/4) | 0 (− 1/1) | −1 (− 4/1) |
FEV1, % pred. | 13 (8/18)* | 7 (−2/20) | 23 (17/30)* | −5 (−15/5) | 9 (3/16)* | 15 (6/25) |
RV/TLC, % | −7 (− 10.9/− 4.0)* | −7 (− 14/0) | − 11 (− 14/− 8)* | 0 (−7/7) | − 4 (− 8/0) | − 4 (− 11/3) |
TLco, % pred. | 11 (6/17)* | 6 (−2/15) | 25 (18/31)* | −5 (− 16/4) | 12 (5/18)* | 18.5 (8/28)* |
Number of comorbidities, N | −1 (− 1/0) | −2 (− 2/− 1)* | − 1 (− 2/− 1)* | −1 (− 2/0)* | −1 (− 1/0)* | 1 (0/1) |
Exacerbations in the previous year, N | 0 (−1/0) | 0 (− 1/1) | − 1 (− 1/0)* | 1 (0/2) | 0 (0/0) | − 1 (− 2/0)* |
Severe exacerbations in the previous year, N | 0 (0/0)* | 0 (0/0) | 0 (0/0)* | 0 (0/0) | 0 (0/0) | 0 (0/0) |
Survival time, days (N = 214) | 332 (49/698) | 884 (328/1358) | 732 (386/1075)* | 461 (− 181/1069) | 303 (62/568)* | −84 (− 701/467) |
6MWD, m | 169.0(182.8/195.2)* | 35.2 (−13.2/83.7) | 210.7 (185.5/236.0)* | − 133.8 (− 184.4/83.2)* | 41.7 (15.6/67.8) | 175.5 (123.8/227.2)* |
6MWD, % pred. | 32 (28/36)* | 2 (− 3/8) | 40 (36/44)* | −29 (− 36/− 22)* | 7 (3/12) | 37 (31/44)* |
SpO2 after 6MWT, % | 2 (0/5)* | 4 (1/7) | −4 (2/7)* | 1 (−1/4) | 2 (4/1) | 1 (−2/3) |
Steps per day, N | 692 (263/1108) | 4770 (3716/6145)* | 5193 (4657/5822)* | 3990 (2916/5641)* | 4477 (3939/5130)* | 349 (− 627/1508) |
Longitudinal properties of the PC-PA quadrant
Differences in clinical characteristics in “changing groups”
Dependent variable | Remainer N = 100 | Decliner N = 29 | Improver N = 20 | Waverer N = 24 | P-value |
---|---|---|---|---|---|
Median annual change BMI, kg/m2 | −0.08 (− 0.75/0.66) | − 0.03 (− 1.09/0.46) | 0.01 (− 0.93/1.02) | 0 (− 0.71/0.35) | 0.740 |
Median annual change Waist/Hip ratio | 0.01 (− 0.03/0.04) | 0.01 (− 0.01/0.03) | −0.01 (− 0.03/0.02) | 0 (− 0.04/0.02) | 0.094 |
Median annual change mMRC score | 0 (0/1) | 0 (0/1) | 0 (− 1/0) | 0 (0/1) | 0.210 |
Median annual change CAT score | 1 (−3/3) | 2 (−2/4) | −1 (− 5/3)† | 1 (− 2/3)‡ | 0.042 |
Median annual change Anxiety score | 0 (− 2/1) | 0 (− 1/1) | 0 (− 2/1) | 0 (− 1/2) | 0.330 |
Median annual change Depression score | 0 (−2/1) | 0 (− 1/2) | − 1 (− 2/0) † | 0.5 (− 1.0/1.5) | 0.045 |
Median annual change FEV1, % pred. | 0 (−4/6) | 0 (− 3/5) | 3 (− 4/6) | − 2 (− 6/1)* | 0.046 |
Median annual change RV/TLC, % | 0 (−5/5) | 1 (− 5/5) | 0 (− 3.0/2.5) | 2.5 (− 2.5/6.0) | 0.180 |
Median annual change TLco, % pred. | −2 (− 6.7/4.0) | − 3 (−9/2) | 0 (− 6/6) | − 1.0 (− 7.0/5.0) | 0.400 |
Median annual change PaO2, kPa | 0.1 (− 0.7/0.6) | −0.21 (− 0.69/0.60) | −0.20 (− 0.82/0.56) | 0.08 (− 0.82/0.75) | 0.840 |
Median annual change PaCO2, kPa | 0 (− 0.31/0.23) | 0.01 (− 0.27/0.20) | −0.10 (− 0.29/0.14) | 0.02 (− 0.17/0.42) | 0.450 |
Median annual change SaO2, % | 0 (− 1.1/1.2) | 0.1 (− 1.5/1.0) | −0.2 (− 1.5/1.0) | 0 (− 1/1) | 0.860 |
Median annual change Number of comorbidities | 0 (0/0) | 0 (0/1) | 0 (0/1) | 0 (0/0) | 0.100 |
Median annual change Exacerbations in the previous year, N | 0 (− 1/0) | 0 (− 1/1) | 0 (−0.5/0.0) | 0 (− 1/1) | 0.850 |
Median annual change Severe exacerbations in the previous year, N | 0 (0/0) | 0 (0/0) | 0 (0/0) | 0 (0/0) | 0.810 |
Median annual change 6MWD, m | 0 (− 30/30) | −25 (− 60.0/28.7) | 11 (− 18/57.5)† | 0 (−75/35) | 0.019 |
Median annual change 6MWD, % pred. | 1.5 (− 3.0/10.0) | 0 (−11/7) | 9.5 (−2/20) | 1 (− 14/14)‡ | 0.005 |
Median annual change SpO2 after 6MWT, % | 0 (−3/3) | −1 (− 3/2) | 0 (− 3/2) | −1 (− 5/4) | 0.540 |
Median annual change Steps per day, N | − 298 (− 1418/566) | − 1202 (− 2926/− 348)* | − 192 (− 1393/1809)† | − 761 (− 1870/665) | < 0.001 |