Functional performance in patients with COPD: association with treatment regimen, GOLD group, lung function, and symptom burden in a cross-sectional study

Figures & data

Table 1 Patient demographics and clinical characteristics

	All (N=1,775)
Mean age, years	65.2
Male, n (%)	978 (55.1)
Ethnicity, n (%)
White/Caucasian	1,277 (71.9)
African American	284 (16.0)
Hispanic/Latino	97 (5.5)
Asian	71 (4.0)
Other	46 (2.6)
Mean body mass index, kg/m^2	27.5
Smoking status,a n (%)
Former	896 (51.1)
Current	632 (36.0)
Never	227 (12.9)
Mean number of pack-years smokedb	32.7
Mean Charlson Comorbidity Index (post-treatment)	1.6
Most common comorbidities,c n (%)
None	947 (53.4)
Hypertension	733 (41.3)
Elevated cholesterol/hyperlipidemia	399 (22.5)
Diabetes mellitus	255 (14.4)
Obesity	255 (14.4)
Coronary heart disease	240 (13.5)
Gastroesophageal reflux disease	205 (11.5)
Depression	184 (10.4)
Anxiety	164 (9.2)
Obstructive sleep apnea	157 (8.8)
Congestive heart failure	154 (8.7)
Previous asthma diagnosis, n (%)	224 (12.6)
Mean time since COPD diagnosis, years	2.1
Patients with exacerbations in the last 12 months, n (%)
0 exacerbations	792 (44.6)
1 exacerbation	234 (13.2)
≥2 exacerbations	749 (42.2)
Mean number of exacerbations	1.0
Physician-reported COPD severity, n (%)
Mild	517 (29.1)
Moderate	809 (45.6)
Severe	333 (18.8)
Very severe	107 (6.0)
Do not know	9 (0.5)
GOLD 2017 groups,d n (%)
GOLD A	257 (14.8)
GOLD B	812 (46.6)
GOLD C	45 (2.6)
GOLD D	627 (36.0)
Mean post-bronchodilator FEV1,e % predicted (SD)	61.2 (18.3)
Mean MVV,f L/min (SD)	87.9 (32.4)
Mean IC,g L (SD)	2.2 (0.7)

Notes:

a N=1,755;

b N=850;

c comorbidities occurring in >150 patients;

d N=1,741;

e N=758;

f N=96;

g N=108.

Abbreviations: GOLD, Global Initiative for Chronic Obstructive Lung Disease; IC, inspiratory capacity; MVV, maximal voluntary ventilation.

Figure 1 Current treatment classes prescribed to COPD patients, overall and by GOLD 2017 group.

Notes: ^aNumber of patients with current treatment regimen identified who were classified by GOLD 2017. ^bPercentages for all patients, and GOLD groups A and B do not add up to 100% due to rounding. ^cOther treatments included, but were not limited to ICS, short-acting bronchodilators in combination with other treatments, and phosphodiesterase-4 inhibitors or oral corticosteroids alone or in combination with other treatments.
Abbreviations: GOLD, Global Initiative for Chronic Obstructive Lung Disease; ICS, inhaled corticosteroid.

Table 2 Patient-reported functional performance (FPI-SF)a by current treatment regimen, mean (SD)

	FPI-SF total	Body care	Maintaining the household	Physical exercise	Recreation: activities for personal pleasure	Spiritual activities	Social interaction; family and friends
Allb (N=1,743)	2.1 (0.7)	2.5 (0.7)	1.8 (0.8)	1.7 (0.8)	2.4 (0.8)	2.1 (1.2)	2.1 (0.9)
Short-acting bronchodilator (N=140)	2.3 (0.7)	2.7 (0.5)	2.2 (0.8)	1.9 (0.8)	2.6 (0.7)	2.1 (1.2)	2.2 (0.9)
Mono long-acting bronchodilator (N=195)	2.2 (0.7)	2.6 (0.7)	2.0 (0.8)	1.8 (0.8)	2.5 (0.8)	2.1 (1.2)	2.2 (0.9)
Dual long-acting bronchodilator (N=153)	2.2 (0.7)	2.6 (0.7)	1.9 (0.8)	1.8 (0.8)	2.6 (0.7)	2.0 (1.2)	2.2 (0.8)
ICS/long-acting bronchodilator (N=648)	2.2 (0.7)	2.6 (0.6)	1.9 (0.8)	1.7 (0.8)	2.5 (0.8)	2.2 (1.1)	2.2 (0.9)
Triple therapy (N=535)	1.9 (0.7)	2.4 (0.7)	1.5 (0.8)	1.4 (0.7)	2.3 (0.8)	2.0 (1.2)	1.9 (0.9)
Otherc (N=72)	2.2 (0.7)	2.6 (0.6)	2.0 (0.9)	1.8 (0.9)	2.6 (0.7)	2.1 (1.2)	2.2 (0.9)

Notes:

a Patients rated how difficult each activity was for them to perform and their responses were scored on a three-point scale: 1= much difficulty, 2= some difficulty, 3= no difficulty. If patients did not perform an activity (either for health reasons or by choice), the item received a score of 0.¹²

b Number of patients with completed FPI-SF who were classified by current treatment regimen.

c Other treatments included, but were not limited to: ICS, short-acting bronchodilators in combination with other treatments, and phosphodiesterase-4 inhibitors or oral corticosteroids alone or in combination with other treatments.

Abbreviations: FPI-SF, Functional Performance Inventory-Short Form; ICS, inhaled corticosteroid.

Table 3 Patient-reported functional performance (FPI-SF)a by GOLD 2017 group, mean (SD)

	FPI-SF total	Body care	Maintaining the household	Physical exercise	Recreation: activities for personal pleasure	Spiritual activities	Social interaction; family and friends
Allb (N=1,718)	2.1 (0.7)	2.5 (0.7)	1.8 (0.8)	1.7 (0.8)	2.4 (0.8)	2.1 (0.9)	2.1 (0.9)
GOLD A (N=254)	2.6 (0.5)	2.9 (0.4)	2.5 (0.6)	2.4 (0.6)	2.9 (0.4)	2.7 (0.6)	2.7 (0.6)
GOLD B (N=800)	2.1 (0.7)	2.6 (0.7)	1.8 (0.8)	1.6 (0.8)	2.4 (0.8)	2.1 (0.9)	2.1 (0.9)
GOLD C (N=45)	2.6 (0.5)	2.8 (0.4)	2.5 (0.6)	2.4 (0.5)	2.8 (0.6)	2.6 (0.7)	2.6 (0.7)
GOLD D (N=619)	1.9 (0.7)	2.3 (0.7)	1.5 (0.8)	1.4 (0.7)	2.2 (0.8)	1.8 (0.9)	1.8 (0.9)

Notes:

a Patients rated how difficult each activity was for them to perform and their responses were scored on a three-point scale: 1= much difficulty, 2= some difficulty, 3= no difficulty. If patients did not perform an activity (either for health reasons or by choice), the item received a score of 0.¹²

b Number of patients with completed FPI-SF who were classified by GOLD 2017.

Abbreviations: FPI-SF, Functional Performance Inventory-Short Form; GOLD, Global Initiative for Chronic Obstructive Lung Disease.

Figure 2 Patient-reported functional performance (FPI-SF)^a by current treatment regimen (A) and GOLD 2017 group (B).

Notes: Error bars represent SD. ^aHigher scores indicate less difficulty with physical activity.^{12 b}Number of patients with completed FPI-SF who were classified by treatment regimen. ^cOther treatments included, but were not limited to ICS, short-acting bronchodilators in combination with other treatments, and phosphodiesterase-4 inhibitors or oral corticosteroids alone or in combination with other treatments. ^dNumber of patients with completed FPI-SF who were classified by GOLD 2017.
Abbreviations: FPI-SF, Functional Performance Inventory-Short Form; GOLD, Global Initiative for Chronic Obstructive Lung Disease; ICS, inhaled corticosteroid; LA, long-acting bronchodilator; SA, short-acting bronchodilator.

Figure 3 Post-bronchodilator FEV₁ % predicted by current treatment regimen (A) and GOLD 2017 group (B).

Notes: Error bars represent SD. ^aNumber of patients with FEV₁ data available who were classified by treatment regimen. ^bOther treatments included, but were not limited to ICS, short-acting bronchodilators in combination with other treatments, and phosphodiesterase-4 inhibitors or oral corticosteroids alone or in combination with other treatments. ^cNumber of patients with FEV₁ data available who were classified by GOLD 2017.
Abbreviations: GOLD, Global Initiative for Chronic Obstructive Lung Disease; ICS, inhaled corticosteroid; LA, long-acting bronchodilator; SA, short-acting bronchodilator.

Table 4 Multiple linear regression analysis between FPI-SF and FEV₁ % predicted

	FPI-SF total (N=735)	Body care (N=738)	Maintaining the household (N=739)	Physical exercise (N=741)	Recreation: activities for personal pleasure (N=741)	Spiritual activities (N=739)	Social interaction; family and friends (N=740)
Regression coefficient	0.0104	0.0103	0.0132	0.0107	0.0086	0.0094	0.0110
r^2 value	0.3299	0.2642	0.3163	0.3322	0.2496	0.0622	0.2605
P-value	0.00	0.00	0.00	0.00	0.00	0.005	0.00

Abbreviation: FPI-SF, Functional Performance Inventory-Short Form.

Table 5 Multiple linear regression analysis between FPI-SF and CAT scores

	FPI-SF total (N=1,691)	Body care (N=1,708)	Maintaining the household (N=1,704)	Physical exercise (N=1,709)	Recreation: activities for personal pleasure (N=1,712)	Spiritual activities (N=1,704)	Social interaction; family and friends (N=1,711)
Regression coefficient	−0.0403	−0.0339	−0.0483	−0.0490	−0.0371	−0.0273	−0.0470
r^2 value	0.4335	0.3202	0.3163	0.4492	0.2960	0.0787	0.3434
P-value	0.00	0.00	0.00	0.00	0.00	0.00	0.00

Abbreviations: CAT, COPD assessment test; FPI-SF, Functional Performance Inventory-Short Form.

Figure 4 Multiple linear regression analysis^a of FPI-SF and FEV₁ % predicted (A) and CAT score (B).

Notes: y =1.5068+0.0104*FEV₁; r² value 0.3299 (A); y =2.8775–0.0403*CAT; r² value 0.4335 (B). ^aThe regression analyses were adjusted for the following variables: patient age, sex, BMI, employment status, currently prescribed treatment, smoking status, and Charlson Comorbidity Index.
Abbreviations: BMI, body mass index; CAT, COPD assessment test; FPI-SF, Functional Performance Inventory-Short Form.

Table S1 Comorbidities

Patients with comorbidities, n (%)	N=1,775
None	947 (53.4)
Cardiovascular condition	935 (52.7)
Angina pectoris	32 (1.8)
Cardiac arrhythmias	105 (5.9)
Coagulated blood clotting disorder	16 (0.9)
Congestive heart failure	154 (8.7)
Coronary heart disease	240 (13.5)
Elevated cholesterol/hyperlipidemia	399 (22.5)
Hypertension	733 (41.3)
Myocardial infarction	75 (4.2)
Peripheral vascular disease	93 (5.2)
Cerebrovascular disease	32 (1.8)
Thrombosis	20 (1.1)
Other cardiovascular condition	26 (1.5)
Dementia	65 (3.7)
Endocrine disorder	333 (18.8)
Diabetes mellitus	255 (14.4)
No end organ damage	214 (12.1)
End organ damage	41 (2.3)
Hyperthyroidism	31 (1.7)
Osteoporosis	48 (2.7)
Other endocrine disorders	41 (2.3)
Glaucoma	96 (5.4)
Gastrointestinal condition	266 (15.0)
Crohn’s disease	10 (0.6)
Dyspepsia/stomach pain	39 (2.2)
Gastroesophageal reflux disease	205 (11.5)
Peptic ulcer disease	13 (0.7)
Other gastrointestinal condition	25 (1.4)
Hematological disorder	40 (2.3)
Anemia	31 (1.7)
Leukemia	4 (0.2)
Other hematological disorder	6 (0.3)
HIV/AIDS	8 (0.5)
AIDS	2 (0.1)
HIV	6 (0.3)
Pulmonary condition	211 (11.9)
Chronic bronchitis	87 (4.9)
Cystic fibrosis	2 (0.1)
Emphysema	80 (4.5)
Idiopathic pulmonary fibrosis	8 (0.5)
Pulmonary arterial hypertension	19 (1.1)
Lung cancer	17 (1.0)
Other pulmonary condition	37 (2.1)
Hemiplegia	8 (0.5)
Malignant lymphoma	13 (0.7)
Obesity	255 (14.4)
Prostate disorder	137 (7.7)
Psychiatric disorder	279 (15.7)
Anxiety	164 (9.2)
Depression	184 (10.4)
Other psychiatric disorder	19 (1.1)
Renal disorder	85 (4.8)
Moderate/severe chronic kidney disease	75 (4.2)
Renal failure	7 (0.4)
Other renal disorder	7 (0.4)
Rhinosinusitis	113 (6.4)
Rheumatic disorder	57 (3.2)
Arthritis	48 (2.7)
Connective tissue/rheumatological disease	11 (0.6)
Other rheumatic disorders	1 (0.1)
Sleep apnea	199 (11.2)
Sleep apnea	55 (3.1)
Obstructive sleep apnea	157 (8.8)
Other sleep apnea	1 (0.1)
Solid tumor	36 (2.0)
Non-metastatic	28 (1.6)
Metastatic	4 (0.2)
Other solid tumor	5 (0.3)
Substance abuse/addiction	107 (6.0)
Systemic sclerosis	4 (0.2)
Other	38 (2.1)

LeidyNKKnebelAIn search of parsimony: reliability and validity of the Functional Performance Inventory-Short FormInt J Chron Obstruct Pulmon Dis2010541542321191436

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Data availability

All relevant data analyzed during this study are included in this published article.