Clinical characteristics and risk of all-cause mortality in low education patients with chronic obstructive pulmonary disease in the Chinese population

BACKGROUND: Education levels play a critical role in the development of chronic obstructive pulmonary disease (COPD), which mainly affects the elderly, who generally have a low level of education in China. We aimed to investigate the association between education level and COPD clinical characteristics and outcomes, especially the effects of education level on the all-cause mortality of COPD in the Chinese population. METHODS: We retrieved data collected between December 2016 and June 2020 in the RealDTC, an ongoing multicenter, real-world study on the status of diagnosis and treatment of COPD. The patients were classified into low- and high-education groups. We extracted data on demographics, pulmonary function, Global Initiative for Chronic Obstructive Lung Disease (GOLD) grades, modified Medical Research Council (mMRC) scores, COPD Assessment Test (CAT) scores, exacerbation history, therapy, and comorbidities, and on mortality during three years of follow-up. RESULTS: We included 4098 patients with COPD, of whom 3258 (79.5%) were of low education. This group had higher ages, CAT scores, mMRC scores, and numbers of exacerbations, as well as a greater proportion of females, never smokers, biofuel exposure, and GOLD grade 3. Logistic regression showed that being aged ≥65 years, being female, having biofuel exposure, having CAT scores of 20-29, and having ≥2 exacerbations were independently associated with having low education (P < 0.05). Furthermore, low-education COPD patients had a higher cumulative mortality risk during three years of follow-up than their high-education counterparts (hazard ratio (HR) = 1.75; 95% confidence interval (CI) = 1.17-2.61, P = 0.006). CONCLUSIONS: Low-education COPD patients, who accounted for most of our sample, had a higher symptom burden, risk of exacerbation, and risk of all-cause mortality. Clinicians attending COPD patients should be more attentive of individuals with low education levels.