The problem there is not the proximate cause of death - pneumonia, heart disease - but the attribution of those proximate causes to second-hand smoke. In the current study, opioid overdose is the clear-cut proximate cause of death, which both the article and the research paper are careful to NOT say was caused by availability of legal medical marijuana.
Granted tha the opioids were the proximate cause of death.... Agreed that the headline does not fully match the report.(not a new phenomenon).
My point was simply that we need to be careful in the conclusions we draw... Because of the time frame this study covers, I can posit any number of reasons that opioid deaths had decreased.... not just the availability of medical marijuana.