DTI Drug Target Insights 2021; 15: 21-25ISSN 1177-3928 | DOI: 10.33393/dti.2021.2291ORIGINAL RESEARCH ARTICLE

Drug Target Insights - ISSN 1177-3928 - www.aboutscience.eu/dti
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Clinical factors predictive of appropriate treatment  
in COPD: a community hospital setting
Sukanya Tongdee1, Bundit Sawunyavisuth2, Wattana Sukeepaisarnjaroen3, Watchara Boonsawat3, Sittichai Khamsai3,  
Kittisak Sawanyawisuth3

1Department of Medicine, Chumpae Hospital, Khon Kaen - Thailand
2Department of Marketing, Faculty of Business Administration and Accountancy, Khon Kaen University, Khon Kaen - Thailand
3Department of Medicine, Faculty of Medicine, Khon Kaen University, Khon Kaen - Thailand

ABSTRACT
Background: Chronic obstructive pulmonary disease (COPD) is a common respiratory disease. The appropriate 
treatment according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guideline was 19-60%. 
However, there are limited data on predictors of appropriate treatment in patients with COPD. This study aimed 
to evaluate risk factors of appropriate treatment in patients with COPD according to the GOLD guideline in a real-
world community setting. 
Methods: This is a retrospective study conducted at a community hospital. Inclusion criteria were adult 
patients diagnosed as COPD treated at a COPD clinic. The primary outcome was the appropriate treatment, 
defined by correct pharmacological treatment by the GOLD guideline according to the ABCD severity assess-
ment. Clinical predictors of appropriate treatment were executed by stepwise multivariate logistic regression 
analysis. 
Results: 136 patients with COPD met the study criteria. Of those, 100 patients had inappropriate treatment 
according to the GOLD guideline. Three factors were independently associated with the appropriate treatment 
including number of admissions, modified Medical Research Council (mMRC) score, and CAT score. These factors 
had adjusted odds ratio of 3.11, 2.86, and 1.26, respectively. Causes of inappropriate treatment were unavail-
ability of long-acting muscarinic antagonist (LAMA) (51 patients; 79.69%), treated by inhaled corticosteroid (ICS) 
alone (12 patients; 18.75%), and treated with only bronchodilator (1 patient; 1.56%).
Conclusions: Appropriate COPD patients’ treatment according to the GOLD guideline was 26.47% in community 
setting. Factors associated with severity of COPD were associated with prescribing appropriate treatments.
Keywords: CAT, hospitalization, mMRC

Received: July 7, 2021
Accepted: October 19, 2021
Published online: November 13, 2021

Corresponding authors:
Sittichai Khamsai and Kittisak Sawanyawisuth
123 Mitraparp Road
Department of Medicine
Faculty of Medicine
Khon Kaen University
Khon Kaen, 40002 - Thailand
sittikh@kku.ac.th and kittisak@kku.ac.th

can be confirmed by evidence of incomplete irreversible 
airflow limitation without other causes. Treatment of COPD 
comprises both pharmacological and nonpharmacological 
modalities such as smoking cessation. Uncontrolled COPD 
may lead to COPD exacerbations and mortality (2). A study of 
73,106 patients with COPD found that the mortality rate was 
50% at 3.6 years after hospitalization (3), while another study 
found that in-hospital mortality rate was 2.6% (4).

There are several factors associated with COPD control 
such as COPD severity, patient compliance, correct inhaler 
technique, or nonpharmacological treatment (5,6). Even 
though patients with COPD had medication adherence of 
51.0%, 85 out of 549 patients or only 15.5% were under 
control (7). Another factor that may be associated with 
COPD symptom control is appropriately prescribed medi-
cation (6,8,9). An undertreatment according to the guide-
line increases risk of COPD exacerbation with a coefficient 
of −0.179 (p < 0.001) (9). The Global Initiative for Chronic  
Obstructive Lung Disease (GOLD) guideline recommends 

Introduction

Chronic obstructive pulmonary disease (COPD) is a respi-
ratory disease mainly caused by smoking. Patients with COPD 
suffer from several symptoms, exacerbations, or hospitaliza-
tions leading to 2.6% of disability-adjusted life years (DALYs) 
and at least 3.2 million deaths globally (1). Diagnosis of COPD 

https:doi.org/10.33393/dti.2021.2291
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COPD community22 

© 2021 The Authors. Drug Target Insights - ISSN 1177-3928 - www.aboutscience.eu/dti

various pharmacological regimens based on COPD severity 
(10). In real practice, the appropriate treatment according 
to the GOLD guideline was 19-60% (9,11,12). However, there 
are limited data on predictors of appropriate treatment in 
patients with COPD. This study aimed to evaluate risk factors 
of appropriate treatment in patients with COPD according to 
the GOLD guideline in a real-world community setting.

Methods

This study was a retrospective study conducted at  
Chumpae Hospital, the largest community hospital in Khon 
Kaen province, Khon Kaen, Thailand. The inclusion criteria 
were adult patients who were diagnosed with COPD and 
treated at the COPD clinic. The diagnosis of COPD was made 
according to the GOLD guideline (10). The study period was 
between May and November 2019. The study protocol was 
approved by the institutional review board, Ministry of Public 
Health, Khon Kaen Branch, Thailand (61165).

Eligible patients were enrolled from clinical charts and 
evaluated for baseline characteristics, smoking history, risk 
factor for COPD, symptoms, chest x-ray, pulmonary function 
test, COPD type, 6-minute walk test (6MW), history of exacer-
bations, history of admission, and COPD assessment.  History 
of cough was defined by the presence of cough for more than 
2 weeks, while productive sputum more than 2 months was 
recorded. COPD assessment was evaluated by using modi-
fied Medical Research Council (mMRC), COPD Assessment 
Test (CAT), and COPD classification by the GOLD guideline or 
ABCD assessment. The primary outcome of the study was the 
appropriate treatment, which was defined by correct phar-
macological treatment by the GOLD guideline to category A 
to D: a bronchodilator for group A; a long-acting bronchodila-
tor (long-acting beta2-agonists: LABA or long-acting musca-
rinic antagonist: LAMA) for group B; LAMA for group C; and 
LAMA or LAMA plus LABA or inhaled corticosteroid (ICS) plus 
LABA for group D. Treatment other than this recommenda-
tion in a particular category was defined as inappropriate 
treatment. The inappropriate treatment was also classified 
as under- and overtreatment according to the recommenda-
tion for each category. Note that information retrieved for 
the study was at the initial therapy of each patient.

Statistical analyses

Patients were categorized into two groups by appropri-
ateness of treatment. The studied variables were compared 
between both groups by descriptive statistics. For numeri-
cal variables, mean and SD was reported and compared be-
tween groups by using independent t-test or Wilcoxon Rank 
Sum test where appropriate. Numbers and percentages of 
each categorical variable were reported and compared be-
tween groups by Chi Square test or Fisher Exact test where 
appropriate. Clinical predictors of appropriate treatment 
were executed by stepwise multivariate logistic regression 
analysis. Those factors with a p value of less than 0.20 by uni-
variate logistic regression were put in the subsequent mul-
tivariate logistic regression analysis. The goodness of fit of 
the final model was tested by Hosmer-Lemeshow method. 

The statistical analyses were executed by the STATA software  
(College Station, Texas, USA).

Results 

There were 136 patients with COPD who met the study 
criteria. Of those, 100 patients (73.53%) were with inappro-
priate treatment according to the GOLD guideline. Between 
those with appropriate and inappropriate treatment groups, 
there were two significant factors in terms of baseline char-
acters including cough and sputum production (Tab. I). The 
appropriate treatment group had higher proportions of  
patients with cough and sputum production than the inap-
propriate treatment group (77.78% vs. 54.00%; and 80.56% 
vs. 60.00%, respectively).

TABLE I - Baseline characters of patients with chronic obstructive 
pulmonary diseases (COPD) categorized by receiving appropriate 
treatment

Factors Inappropriate 
n = 100

Appropriate 
n = 36

p  
value

Mean (SD) age, years 64.51 (8.83) 63.47 (10.51) 0.566

Male sex, n (%) 94 (94.00) 35 (97.22) 0.675

Occupation:  
agricultural, n (%)

93 (93.00) 31 (86.11) 0.412

Diabetes mellitus, n (%) 8 (8.00) 7 (19.44) 0.060

Hypertension, n (%) 42 (42.00) 17 (47.22) 0.588

Dyspnea, n (%) 100 (100.00) 37 (100.00) NA

Cough, n (%) 54 (54.00) 28 (77.78) 0.012

Sputum, n (%) 60 (60.00) 29 (80.56) 0.026

Smoking history, n (%) 0.992

 None 9 (9.00) 3 (8.33)

 Ex-smoker 72 (72.00) 26 (72.22) 

 Current smoker 19 (19.00) 7 (19.44)

Mean (SD) pack-year of 
smoking

21.49 (15.40) 26.82 (29.24) 0.498

Exposure to noxious  
particles, n (%)

6 (6.00) 2 (5.56) 0.999

Mean (SD) BMI (kg/m2) 21.17 (3.69) 21.90 (3.95) 0.446

BMI = body mass index; NA = not available.

Between these two groups, the appropriate treatment 
group had shorter 6MW test (328.05 vs. 353.49 m) and 
lower mMRC (1.83 vs. 0.96) than the inappropriate treat-
ment group significantly (Tab. II). But the average CAT score 
(15.88 vs. 7.22), average number of exacerbation (2.83 vs. 
1.13 times), and average number of admissions (2.83 vs. 1.13 
times) were significantly higher in the appropriate treatment 
group than the inappropriate treatment group (Tab. II) while 
the post-bronchodilator FEV1/FVC was significantly lower 
in the appropriate treatment group than the inappropriate 
treatment group (53.19 vs. 57.32; p = 0.033). COPD class D 



Tongdee et al Drug Target Insights 2021; 15: 23

© 2021 The Authors. Published by AboutScience - www.aboutscience.eu

was also found more in the appropriate treatment group 
than the inappropriate treatment group (100.00% vs. 3.00%).

There were five factors remaining in the final model 
predictive of appropriate treatment in patients with COPD 
(Tab. III). Of those, three factors were independently asso-
ciated with the appropriate treatment including number of 
admissions, mMRC score, and CAT score. These factors had 
adjusted odds ratio of 3.11, 2.86, and 1.26, respectively. The 
final model had the Hosmer-Lemeshow chi-square of 10.72 
(p = 0.218), indicating goodness of fit of the model. Causes 
of inappropriate treatment were unavailability of LAMA  

(51 patients; 79.69%), treated by ICS alone (12 patients; 
18.75%), and treated with only bronchodilator (1 patient; 
1.56%). Categorized by COPD category, overtreatment was 
found in categories A, B, and C, while undertreatment was 
reported in categories B, C, and D (Tab. IV).

TABLE IV - Proportions of under- or overtreatment by chronic  
obstructive airway disease category (n = 100)

Treatment A (n = 42) B (n = 30) C (n = 25) D (n = 3)

Undertreatment 0 6 (20.00) 2 (8.00) 3 (100.00)

Overtreatment 42 (100.00) 24 (80.00) 23 (92.00) 0

Discussion

This study showed that the appropriate treatment for 
patients with COPD was 26.47%: in category D at 100.00% 
(Tab. II). Compared with other three previous studies, this 
study had appropriate treatment rate comparable with the 
study at VA hospital in the US (27.2% vs. 18.7%) and lower 
than two studies from tertiary hospitals. In this community 
hospital setting, patients with category D had highest appro-
priate treatment rate than others at 100.00% (Tab. II). This 
pattern was also found in other studies which may indicate 
that severe cases of COPD tend to follow the GOLD guideline 
as they may have severe symptoms and required appropriate 
and several pharmacological therapies (10,13). 

This study also found another similar pattern on appro-
priate treatment: low appropriate treatment rate in catego-
ries A, B, and C. First, we found that inhaled corticosteroid 
alone was used in 12 patients or 18.75%. The study from Italy 
also found that inhaled corticosteroid was overused despite 
the GOLD guideline that does not recommend it as shown 
in Table V (11). But, the attending physicians believe that it 
is more effective. A study from Sweden also found that in-
haled corticosteroid was used inappropriately in 45.5% of pa-
tients with COPD regardless of categories: A 33.6%; B 46.2%; 

TABLE II - Laboratory results and disease status of patients with 
chronic obstructive pulmonary diseases (COPD) categorized by  
receiving appropriate treatment

Factors Inappropriate 
n = 100

Appropriate 
n = 36

p 
value

CXR, n (%)

 Normal, n (%) 53 (53.00) 19 (52.78)   0.982

 Hyperinflation, n (%) 36 (36.00) 13 (36.11)   0.990

Post-bronchodilator  
FEV1, mL

66.86 (17.40) 60.30 (19.11)   0.061

Post-bronchodilator  
FEV1, %

6.02 (7.00) 6.80 (7.21)   0.602

Post-bronchodilator 
FEV1/FVC

57.32 (9.17) 53.19 (9.99)   0.033

COPD type, n (%)   0.999

 Chronic bronchitis 3 (3.00) 1 (2.78)

 Emphysema 5 (5.00) 1 (2.78)

 Mixed 92 (92.00) 34 (94.44)

Mean (SD) 6MW,  
meters

353.49 (72.91) 328.05 (87.16)   0.222

mMRC, n (%) 0.96 (0.66) 1.83 (0.88) <0.001

 0 22 (22.00) 1 (2.78)

 1 62 (62.00) 13 (36.11)

 2 14 (14.00) 14 (38.89)

 3 2 (2.00) 7 (19.44)

 4 0 1 (2.78)

Mean (SD) CAT 7.22 (5.31) 15.88 (5.04) <0.001

Exacerbation, n (%) 1.13 (2.40) 2.83 (2.09) <0.001

Admission, n (%) 0.26 (0.75) 1.22 (1.17) <0.001

Category, n (%) <0.001

 A 42 (42.00) 0

 B 30 (30.00) 0

 C 25 (25.00) 0

 D 3 (3.00) 36 (100.00)

6MW = 6-minute walk test; CAT = COPD Assessment Test; mMRC = modi-
fied Medical Research Council dyspnea questionnaire; COPD category by the 
GOLD guideline. 

TABLE III - Factors predictive of appropriate treatment in chronic 
obstructive pulmonary diseases (COPD) treated at community  
hospital

Factors Unadjusted odds ratio  
(95% confidence  

interval)

Adjusted odds ratio  
(95% confidence  

interval)

Age 0.99 (0.95, 1.03) 0.94 (0.89, 1.01)

Diabetes 2.77 (0.93, 8.31) 3.10 (0.46, 20.84)

Admission 3.73 (2.02, 6.88) 3.11 (1.39, 6.97)

mMRC 4.47 (2.41, 8.30) 2.86 (1.18, 6.94)

CAT 1.32 (1.19, 1.47) 1.26 (1.13, 1.42)

Factors in the model included sex, smoking, cough, sputum, body mass index, 
chest x ray, 6-minute walk test, post-bronchodilator FEV1, post-bronchodila-
tor FEV1/FVC, and exacerbation. 
CAT = COPD Assessment Test; mMRC = modified Medical Research Council 
dyspnea questionnaire.



COPD community24 

© 2021 The Authors. Drug Target Insights - ISSN 1177-3928 - www.aboutscience.eu/dti

C 54.8%; and D 71.0% (14). An inappropriate use of inhaled 
corticosteroid was also found in 50% of patients with COPD 
in the UK (15). Another limitation for community hospital in 
this study is lack of LAMA in 79.69%: it may be due to unavail-
ability and cost of LAMA. 

Not surprisingly, factors predictive for appropriate treat-
ments were factors indicating severe COPD including hospital 
admissions, mMRC, and CAT score (Tabs. II and III). Among 
these three factors, admissions and mMRC had higher  
adjusted odds ratios than the CAT score. These may imply 
that the two factors are slightly stronger predictors for se-
vere COPD than the CAT score (9,10,13). Additionally, hospi-
talizations may remind physicians to prescribe more proper 
medications for the patients as they may have more times to 
assess the patients than in the outpatient setting (16). 

This study had some limitations. First, we did not evalu-
ate association of COPD such as obstructive sleep apnea 
(OSA) or asthma which may result in overprescription of 
corticosteroids (17-21). Second, the study population was 
community hospital. The results of this study may not be 
applied for more complicated COPD patients. Second, there 
was no follow-up data on long-term outcomes. Finally, 
 inappropriate treatment of not using LAMA was due to un-
availability. Other causes of inappropriate treatment were 
treatment with only ICS (18.75%) or bronchodilator alone 
(1.56%).

Conclusion

Appropriate treatment of patients with COPD according 
to the GOLD guideline was 26.47% in community setting.  
Factors associated with severity of COPD were associated 
with prescribing of appropriate treatments. 

Acknowledgments

The authors would like to thank Research Center in Back, 
Neck Other Joint Pain and Human Performance (BNOJPH), 
Khon Kaen University, Khon Kaen, Thailand.

Disclosures
Conflict of interest: The authors declare that they have no conflicts 
of interest.
Financial support: None.

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18/41  
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234/272 
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19/379  
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73/292 
(25.0%)

42/121 
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Chan, 2017 Hong Kong Tertiary Hospital 262/450 
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1/5  
(20.0%)

7/164  
(1.6%)

0/8  
(0%)

254/273 
(56.4%)

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(26.47%)

0/42  
(0%)

0/30  
(0%)

0/25  
(0%)

36/39 
(92.31%)

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