Table 1 Baseline characteristics and summary statistics

Males n (%)

Females n (%)

Age median (IQR^a)

Education < 10 years n (%)

Education 10–12 years n (%)

Education > 12 years n (%)

Homelessness n (%)

Social security benefits as income n (%)

Formal work as income n (%)

Methadone n (%)

Buprenorphine n (%)

Other opioid agonist treatment medications n (%)

Substance use last 30 days n (%)

Illicit opioids

Alcohol

Amphetamines or cocaine

Benzodiazepines

Cannabis

I.v. drug use last 6 months

Debut age smoking median (IQR^a)

Years of smoking median (IQR^a)

Average daily number of cigarettes smoked

Body mass index median (IQR^a)

Obstructive pulmonary disease^b n (%)