Burden and treatment of chronic obstructive pulmonary disease among people using illicit opioids: matched cohort study in England

OBJECTIVE: To understand the burden of chronic obstructive pulmonary disease among people who use illicit opioids such as heroin, and evaluate inequalities in treatment. DESIGN: Cohort study. SETTING: Patients registered at primary care practices in England. PARTICIPANTS: 106 789 patients in the Clinical Practice Research Datalink with illicit opioid use recorded between 2001 and 2018, and a subcohort of 3903 patients with a diagnosis of chronic obstructive pulmonary disease. For both cohorts, the study sampled a comparison group with no history of illicit opioids that was matched by age, sex, and general practice. MAIN OUTCOME MEASURES: In the base cohort: diagnosis of chronic obstructive pulmonary disease and death due to the disease. In the subcohort: five treatments (influenza vaccine, pneumococcal vaccine, pulmonary rehabilitation, bronchodilators or corticosteroids, and smoking cessation support) and exacerbations requiring hospital admission. RESULTS: 680 of 106 789 participants died due to chronic obstructive pulmonary disease, representing 5.1% of all cause deaths. Illicit opioid use was associated with 14.59 times (95% confidence interval 12.28 to 17.33) the risk of death related to chronic obstructive pulmonary disease, and 5.89 times (5.62 to 6.18) the risk of a diagnosis of the disease. Among patients with a new diagnosis, comorbid illicit opioid use was associated with current smoking, underweight, worse lung function, and more severe breathlessness. After adjusting for these differences, illicit opioids were associated with 1.96 times (1.82 to 2.12) times the risk of exacerbations requiring hospital admission, but not associated with a substantially different probability of the five treatments. CONCLUSIONS: Death due to chronic obstructive pulmonary disease is about 15 times more common among people who use illicit opioids than the general population. This inequality does not appear to be explained by differences in treatment, but late diagnosis of the disease among people who use illicit opioids might contribute.