You are here:

Regular cannabis use, with and without tobacco co-use, is associated with respiratory disease

posted 16/09/2019



TheresaWinhusena  JeffTheobalda    David C.Kaelberbcd    DanielLewisa

Addiction Sciences Division, Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati College of Medicine, 3131 Harvey Avenue, Cincinnati, OH 45229, USA

Department of Information Services, The MetroHealth System, Cleveland, OH, USA

Departments of Internal Medicine, Pediatrics, and Population and Quantitative Health Sciences, Case Western Reserve University, Cleveland, OH, USA

The Center for Clinical Informatics Research and Education, The MetroHealth System, Cleveland, OH, USA



•  The role of cannabis use in respiratory disease, apart from tobacco use, is unclear.

•   Regular cannabis use in U.S. adults has increased significantly in recent years.

•   Our matching and analysis method reduce potential confounds in observational data.

•   Regular cannabis use was associated with greater risk of respiratory disease.



Cannabis use is a potential risk factor for respiratory disease but its role apart from tobacco use is unclear. We evaluated the association between regular cannabis use, with and without tobacco co-use, and onset of asthma, chronic obstructive pulmonary disease (COPD), and pneumonia.


Analysis of a limited data set obtained through IBM Watson Health Explorys, an electronic-health-record-integration platform. Matched controls using Mahalanobis distance within propensity score calipers were defined for: 1) cannabis-using patients (n = 8932); and subgroups of cannabis-using patients: 2) with an encounter diagnosis for tobacco use disorder (TUD; n = 4678); and 3) without a TUD diagnosis (non-TUD; n = 4254). Patients had at least: one recorded blood pressure measurement and one blood chemistry lab result in the MetroHealth System (Cleveland, Ohio). Cannabis-using patients had an encounter diagnosis of cannabis abuse/dependence and/or ≥2 cannabis-positive urine drug screens (UDSs). Control patients, not having cannabis-related diagnoses or cannabis-positive UDSs, were matched to the cannabis-using patients on demographics, residential zip code median income, body mass index, and, for the total sample, TUD-status.


Regular cannabis use was significantly associated with greater risk for asthma (odds ratio (OR) = 1.44; adjusted odds ratio (aOR) = 1.50; OR = 1.32), COPD (OR = 1.56; aOR = 1.44; OR = 2.17), and pneumonia (OR = 1.80; OR = 1.84; OR = 2.13) in the total sample and TUD and non-TUD subgroups, respectively. TUD-patients had the greatest prevalence of respiratory disease, regardless of cannabis-use indication.


Regular cannabis use is associated with significantly greater risk of respiratory disease regardless of TUD status. Future research to understand the impact of cannabis use on respiratory health is warranted.

get involved

If you are interested in what we do and would like to support our work, find out more ways to get involved.


get our book

Drugs: It’s just not worth it

Drugs: It’s just not worth it

Our 35-page book gives clear and easy to read facts and advice aimed at teenagers and young people.


Buy Now