Potential limitations and implications
“The fact that COPD- or pneumonia-related mortality was not observed to occur with significantly greater rates among cannabinoid users with COPD may suggest that the increased all-cause mortality finding was not being driven by adverse respiratory-related drug effects, as we hypothesized, and instead was possibly a result of unresolved confounding,” the researchers noted.
The study findings were limited by several factors including the inability to prove causation in an observational study, and the potential for confounding based on unmeasured differences between cannabinoid users and nonusers, the researchers said. “Our findings may not be generalizable to all individuals with COPD, as our study included only those aged 66 years and older, and our COPD identification algorithm, while highly specific, had modest sensitivity,” they added. However, the results were strengthened by the large study population and suggest that cannabinoids are not contraindicated for older adults with COPD, the researchers said. “There can be legitimate reasons for using cannabinoids in this population, such as to help treat chemotherapy-related nausea and vomiting, and possibly for end-of-life care,” they emphasized.
The study findings serve to inform clinicians of the significantly increased mortality risk when older adults with COPD initiate cannabinoids, and “this information should be discussed with patients and incorporated in prescribing decision-making and management plans,” along with consideration of using lower doses when possible to minimize adverse events, they concluded.
The study was supported by The Lung Association – Ontario Grant Review/Grant-In-Aid. The researchers had no financial conflicts to disclose.