Chronic obstructive pulmonary disease (COPD) among opioid-dependent patients in agonist treatment. A diagnostic study

Aims: To estimate the prevalence of chronic obstructive pulmonary disease (COPD) and related risk factors in people in opioid agonist treatment (OAT), to compare airflow limitation severity and age-specific COPD prevalence rates with those in the general population, and to assess the OAT patients' willingness to adopt life-style changes and to use therapeutic offers for COPD management.

Design: Cross-sectional study in a random sample of OAT patients.

Setting: Out-patient centres for substance addiction medicine in Zurich, Switzerland.

Participants: A total of 125 participants, recruited from November 2016 to April 2017 through invitation letters followed by phone or personal contact.

Measurements: Standardized questionnaires about drug use, smoking habits and medical history, completed during face-to-face interviews or from medical records. Spirometry without and-depending on the result-with bronchodilation.

Findings: Almost one-third [30.3%; 95% confidence interval (CI) = 22.6-39.0%] of the 119 participants with valid spirometry tests were diagnosed with COPD. Among males aged 30-59 years, the age-adjusted prevalence of at least moderate airflow limitation (GOLD grade ≥ 2) was 2.4 (95% CI = 1.3-4.4) times as high as in the ever-smoking Swiss population in the same age group. Smoking tobacco (92.0%) and substance inhalation (cannabis = 97.6%, cocaine = 69.6%, heroin = 68.0%) were highly prevalent among all participants. The participants expressed considerable interest in life-style changes and use of therapeutic offers for COPD management, with smoking cessation being least (20.2% of tobacco smokers interested) and pharmacological treatment to alleviate COPD symptoms most popular.

Conclusions: In Switzerland, COPD prevalence and multiple risk factors for COPD appear to be high among people in OAT compared with the general population. Individuals in OAT appear to develop COPD at a younger average age compared with the general population and are open to life-style changes and other COPD management approaches.