The study was published in the Canadian Journal of Anaesthesia January 20, 2021. Opioid use decreased by almost half, from 40.8 per cent at baseline to 23.9 percent at 12 months.
Another recent Canadian study found that using cannabis significantly reduced opioid use and improved quality of life. For those who used opioids, the daily amount fell 78 per cent from 152 mg morphine milligram equivalent (MME) at baseline to 32.2 mg MME at six months.
The original article and link to the actual study are here.