We investigated patients with
chronic obstructive pulmonary disease (
COPD) to analyze patterns and identify determinants of healthcare use, according to the severity of airflow obstruction. We used retrospective cohort data from a combination of the 4th Korea National Health and Nutritional Examination Survey (KNHANES) and Korean National Health Insurance (NHI) claims.
METHODS: Demographic and medical claims data were retrospectively analyzed from the 4th KNHANES along with NHI claims. Eligible patients were aged ≥40 years, who underwent complete pulmonary function tests (PFTs), and had at least one inpatient or outpatient claim coded as
COPD between January 1, 2007 and December 31, 2010.
RESULTS: Among 6,663 eligible participants, 897 (13.5%) had
airway obstruction. Self-reported physician-diagnosed
COPD comprised only 3%, and there were 870 undiagnosed
COPD patients (97%). Self-reported physician-diagnosed
asthma made up 3.7%. Of the 897 respondents, 244 (27.2%) used
COPD-related healthcare services. The frequency of healthcare visits increased with increasing severity of
airway obstruction. After a 3-year follow-up period, 646 (74.2% of those initially undiagnosed) remained undiagnosed and only 224 (25.8%) were diagnosed and treated for
COPD. Only 27.5% of the 244 participants with
airway obstruction who used
COPD-related healthcare underwent PFTs during the study period. The percentage of prescribed medications associated with
COPD increased in accordance with the severity of the
COPD. Inhaled long-acting
anticholinergics were prescribed for 10.9% of patients with moderate
airway obstruction and for 52.4% of patients with severe obstruction. Inhaled long-acting β-agonists combined with
corticosteroids were prescribed for 50% of patients with severe
airway obstruction. Conversely, 44.6% of healthcare users were prescribed oral
theophylline for
COPD treatment, and 21.7% were also prescribed an oral
corticosteroid. The determinants of
COPD-associated healthcare use in respondents with
obstructive lung disease were advanced age, severe airflow limitation, presence of comorbidities, and self-reported physician diagnosis of
COPD.
CONCLUSIONS: This study ascertained marked underdiagnosed
COPD. Although the percentage of prescribed medication used to treat
COPD increased with the severity of the
COPD, medications primarily prescribed such as oral
theophylline or oral
corticosteroids are inappropriate for first-line
COPD treatment.