The effect of marijuana use on respiratory complications and pulmonary function was examined in this study. Researchers selected 34 published studies that addressed the impact of marijuana use on airway response, abnormal pulmonary function and respiratory complications. A qualitative review of the articles focused on research methods and clinical applicability.
- Twelve of the studies reviewed were deemed challenge studies, or studies that explored the relationship between short-term marijuana smoking and airway response.
- A relationship between marijuana use and airway response existed in the majority of challenge studies.
- All studies of long-term marijuana use and respiratory complications observed higher levels of respiratory symptoms such as coughing or wheezing for those who used marijuana for longer periods.
- No stable relationship between long-term marijuana smoking and pulmonary function, such as airway hyperreactivity, was found.
- Limitations in research methodology, for example, not adjusting for confounding variables in data analysis, contributed to the variability in studies' quality.