Treatment Patterns, Socioeconomic Status and Clinical Burden in Mild COPD: A Swedish Real-World, Retrospective Cohort Study, the ARCTIC Study

Figures & data

Table 1 Patient Demographics of the Mild COPD and Reference Groups

Variable	Mild COPD Patients (N=844)	Reference Population (N=844)
Age (years)
Mean (SD)	62.6 (10.9)	62.6 (10.9)
Sex, n (%)
Men	353 (41.8%)	353 (41.8%)
BMI (kg/m^2)
Normal weight (BMI 18.5–24.9)	167 (19.8%)	21 (2.5%)
Obese (≥30.0)	83 (9.8%)	13 (1.5%)
Overweight (25.0–29.9)	157 (18.6%)	12 (1.4%)
Underweight (<18.5)	13 (1.5%)	1 (0.1%)
Missing	424 (50.2%)	797 (94.4%)
Smoking
Non-smoker	71 (8.4%)	51 (6.0%)
Smoker	114 (13.5%)	13 (1.5%)
Ex-smoker	43 (5.1%)	2 (0.2%)
Missing	616 (73.0%)	778 (92.2%)

Abbreviations: BMI, body mass index; COPD, chronic obstructive pulmonary disease; SD, standard deviation.

Table 2 Socioeconomic Status of the Mild COPD and Reference Groups

Variable	Mild COPD Patients (N=844)	Reference Population (N=844)	P-value^$
Education, n (%)
Elementary school <9 years	184 (21.8%)	139 (16.5%)	<0.0001
Elementary school ≥9 years	99 (11.7%)	79 (9.4%)
High school 2 years	282 (33.4%)	211 (25.0%)
High school 3 years	86 (10.2%)	98 (11.6%)
University education <3 years	94 (11.1%)	110 (13.0%)
University education ≥3 years and PhD	91 (10.8%)	188 (22.3%)
Missing	8 (0.9%)	19 (2.3%)
Employment status, n (%)
Employed	358 (42.4%)	405 (48.0%)	0.0010
Retired	342 (40.5%)	344 (40.8%)
Unemployment	143 (16.9%)	91 (10.8%)
Missing	1 (0.1%)	4 (0.5%)
Annual income (€) from work
N	501	526	<0.0001
Mean (SD)	13,847.5 (14,715.0)	21,368.4 (19,164.3)
Marital status, n (%)
Married	386 (45.7%)	434 (51.4%)	0.0005
Unmarried	457 (54.1%)	399 (47.3%)
Missing	1 (0.1%)	11 (1.3%)
Sick leave
Any absenteeism due to sickness, n (%)	139 (16.5%)	102 (12.1%)	0.0100
Sickness benefit (number of net days), mean (SD)	29.5 (75.1)	16.8 (56.6)	<0.0001
Comorbidities*, n (%)
Cardiovascular disease (I00-I99)	286 (33.9%)	195 (23.1%)	<0.0001
Congestive heart failure (I09.9 + I11.0 + I13.0 + I13.2 + I25.5 + I42.0 + I42.5-I42.9 + I43 + I50 + P29.0)	4 (0.5%)	4 (0.5%)	1.0000
Ischaemic heart disease, (I20-I25)	68 (8.1%)	49 (5.8%)	0.069
Diabetes type I (E10)	7 (0.8%)	18 (2.1%)	0.027
Diabetes type II (E11 + E13)	31 (3.7%)	41 (4.9%)	0.23
Lung cancer (C34)	0 (0.0%)	3 (0.4%)	0.083
Depression (F32 + F33)	63 (7.5%)	23 (2.7%)	<0.0001
Anxiety (F40 + F41)	48 (5.7%)	13 (1.5%)	<0.0001
Osteoporosis (M80 + M81)	26 (3.1%)	7 (0.8%)	0.0008
Co-medications*, n (%)
Cardiovascular disease medications (C01-C10)	377 (44.7%)	322 (38.2%)	0.0066
Cognitive impairment medications (Alzheimer’s disease) (N06DA)	0 (0.0%)	0 (0.0%)	1.0000
Proton pump inhibitors (A02)	212 (25.1%)	112 (13.3%)	<0.0001
Antidepressants (N06A)	180 (21.3%)	81 (9.6%)	<0.0001
Statins (C10AA + C10B)	140 (16.6%)	138 (16.4%)	0.8956
Central painkillers (N02BE + N02A + M01AE)	292 (34.6%)	179 (21.2%)	<0.0001
Sleep medications (N05C)	40 (4.7%)	7 (0.8%)	<0.0001
Bisphosphonates (M05BA)	33 (3.9%)	15 (1.8%)	0.0084
Beta blockers (C07)	178 (21.1%)	149 (17.7%)	0.074
Antidiabetics (A10)	40 (4.7%)	55 (6.5%)	0.11
Nasal corticosteroids (R01AD)	0 (0.0%)	0 (0.0%)	>0.99
Healthcare resource utilization*
Number of inpatient visits, mean (SD)	0.6 (1.9)	0.5 (1.2)	0.078
Number of outpatient clinic visits, mean (SD)	3.2 (4.4)	3.4 (14.5)	0.0006
Length (in days) of hospitalization, mean (SD)	2.7 (11.5)	2.5 (9.6)	0.10
Number of primary care visits^#, mean (SD)	13.3 (17.2)	3.9 (10.6)	<0.0001

Notes: Bold values denote statistical significance at the p < 0.05 level; *data on comorbidities, co-medications and healthcare resource utilization are 2 years prior to the index date; ^$the p-values are calculated using a chi-square test (categorical variables) or ANCOVA (continuous variables); ^#all visits are included such as doctors’ visits, nurse visits, etc.

Abbreviations: COPD, chronic obstructive pulmonary disease; PhD, Doctor of Philosophy; SD, standard deviation.

Figure 1 Flowchart of patient inclusion and exclusion criteria.

Table 3 Post-Bronchodilator Lung Function, Exacerbations and Respiratory Medications in Patients with Mild COPD

Variable	Mild COPD Patients
	N	Mean (95% CI)
Lung function*
FEV1% predicted after bronchodilation	844	91.0 (90.1, 92.0)
FVC% predicted after bronchodilation	756	94.2 (92.9, 95.5)
Exacerbations^#	N	Annual exacerbation rate
Moderate exacerbations	844	0.64 (0.61, 0.68)
Severe exacerbations	844	0
Pharmacological treatment^#	N	n (%)
LABA	844	387 (45.9%)
LAMA	844	333 (39.5%)
SABA	844	407 (48.2%)
Combination of ICS + LABA	844	287 (34.0%)
Combination of LABA + LAMA	844	1 (0.1%)

Notes: *Lung function values are those closest to (either before or after) the index date; ^#data reported during follow-up period; N (%) indicate the number of patients and (percent of patients in that group) in whom lung function measurements were available.

Abbreviations: CI, confidence interval; COPD, chronic obstructive pulmonary disease; FEV₁, forced expiratory volume in one second; FVC, forced vital capacity; ICS, inhaled steroids; LABA, long-acting beta-agonists; LAMA, long-acting antimuscarinics; SABA, short-acting beta-agonists.

Figure 2 Annual income from work, in Euros.

Table 4 Comparative Analysis Between Mild COPD Patients vs the Reference Population Over Time Stratified by Gender

Variable	Men		Women
	Odds Ratio (95% CI)	P-value	Odds Ratio (95% CI)	P-value
Socioeconomic status
Employed	0.46 (0.30, 0.72)	0.0007	0.49 (0.34, 0.70)	<0.0001
Married	0.64 (0.42, 0.96)	0.0301	0.48 (0.34, 0.67)	<0.0001
Any absenteeism due to sickness	1.96 (1.28, 3.00)	0.0020	1.86 (1.35, 2.55)	0.0001
No. of absenteeism days due to sickness	3.36 (1.95, 5.79)	<0.0001	2.16 (1.47, 3.19)	0.0001
Comorbidities
Cardiovascular disease	1.54 (1.02, 2.34)	0.0398	1.53 (1.07, 2.17)	0.0186
Congestive heart failure	2.08 (0.77, 5.61)	0.1486	4.99 (0.53, 47.40)	0.1616
Ischaemic heart disease	1.13 (0.53, 2.42)	0.7496	2.30 (0.83, 6.40)	0.1098
Diabetes type I	1.70 (0.16, 18.58)	0.6633	0.21 (0.02, 1.83)	0.1563
Diabetes type II	1.93 (0.81, 4.56)	0.1365	1.94 (0.73, 5.16)	0.1825
Lung cancer	0.33 (0.03, 3.74)	0.3704	8.83 (0.88, 88.46)	0.0638
Depression	1.70 (0.72, 4.00)	0.2286	4.00 (2.15, 7.44)	<0.0001
Anxiety	6.34 (1.79, 22.39)	0.0041	5.48 (2.62, 11.45)	<0.0001
Co-medications*
Medications for cardiovascular disease	1.31 (0.89, 1.94)	0.1726	1.21 (0.88, 1.67)	0.2468
Proton pump inhibitors	2.17 (1.33, 3.56)	0.0020	1.67 (1.19, 2.33)	0.0032
Antidepressants	2.39 (1.39, 4.10)	0.0015	3.17 (2.15, 4.66)	<0.0001
Statins	1.02 (0.64, 1.63)	0.9249	1.27 (0.81, 1.97)	0.2949
Central painkillers	2.11 (1.29, 3.43)	0.0028	2.11 (1.54, 2.88)	<0.0001
Sleep medications	3.36 (1.49, 7.57)	0.0035	5.09 (2.74, 9.47)	<0.0001
Beta blockers	1.04 (0.65, 1.66)	0.8668	1.47 (0.95, 2.26)	0.0801
Antidiabetics	1.11 (0.54, 2.28)	0.7687	0.66 (0.29, 1.51)	0.3265
Nasal corticosteroids	1.26 (0.74, 2.14)	0.4033	2.07 (1.40, 3.06)	0.0003
Healthcare resource utilization
No. of inpatient visits	1.10 (0.42, 2.89)	0.8530	0.69 (0.23, 2.05)	0.5010
Length of hospitalization	0.47 (0.10, 2.25)	0.3477	0.32 (0.09, 1.07)	0.0651
No. of primary care visits	1.32 (0.97, 1.79)	0.0737	1.54 (1.32, 1.79)	<0.0001

Notes: Bold values denote statistical significance at the p < 0.05 level; odds ratios above 1.00 indicate a higher value in the COPD group; significant results are indicated by bolded p-values. *Some of the co-medications reported in Table 1 are not included since they were not used by any patient in either group.

Abbreviations: CI, confidence interval; COPD, chronic obstructive pulmonary disease; No, number.