Fig. 2.
Changes in chronic postoperative opioid use. The proportion of patients with chronic postoperative opioid use (per 1,000 total knee arthroplasties) decreased every month, gradually, up to October 2013. However, there was a significant decline after roll out of the Opioid Safety Initiative (interrupted vertical line), with 20% fewer patients continuing chronic opioid use when compared to the number expected based on pre–Opioid Safety Initiative trends (observed n = 3,355 vs. expected n = 4,226). TKA, total knee arthroplasty.