Chronic obstructive pulmonary disease (COPD) is characterized by persistent and progressive airflow limitation, and a new study examined the factors responsible for a high St George’s Respiratory Questionnaire for COPD (SGRQ-C) based on severity of airflow limitation.
The study, published in the International Journal of COPD
, included 1264 patients who were categorized into 2 groups based on the severity of airflow limitation: mild-to-moderate COPD and severe-to-very severe COPD.
“The substantial symptomatic burden of COPD reduces physical and psychological functioning, ultimately decreasing health-related quality of life (HRQoL),” explained the authors.
They sought to analyze the SGRQ-C, which is used to grade symptoms, to identify factors associated with a high score in patients with stable COPD based on the severity of airflow limitation.
The study selected patients in the Korean COPD Subgroup Study cohort and recorded a variety of data, including age, sex, height, weight, smoking status, comorbidities, 6-minute walk distance, cough, sputum, and SGRQ-C score. Of the 902 patients who had mild-to-moderate COPD, 534 (59.2%) had a high SGRQ-C score, and of the 362 patients with severe-to-very severe COPD, 261 (80.4%) had a high SGRQ-C score.
Compared with patients with a low SGRQ-C score, patients with mild-to-moderate COPD and a high score were more likely to be less educated, have more comorbidities, and suffer from more respiratory symptoms, such as cough, sputum, and dyspnea. These patients also had a “significantly lower level” of exercise capacity as determined by the 6-minute walk distance.
Patients with severe-to-very severe COPD and a high score were more likely to have a lower body mass index, a history of pneumonia, osteoporosis, and respiratory symptoms, such as cough, sputum, and dyspnea. Similar to patients with mild-to-moderate COPD, this group had a significantly shorter 6-minute walk distances compared with similar patients with a low SGRQ-C score. No comorbidities were associated with a high score for this group.
Overall, the researchers found a negative correlation between HRQoL and severity of airflow limitation. The fact that only respiratory symptoms were significantly associated with a high SGRQ-C score “indicates the need for an improved management strategy for relieving respiratory symptoms in COPD patients with poor HRQoL,” the authors concluded.