Guy GP, et al. - In the present study, researchers tested the premise that the Centers for Disease Control and Prevention (CDC) guideline release corresponded to declines in specific opioid prescribing practices. Findings revealed that the overall opioid prescribing rate was 6577 per 100,000 persons in January 2012 and declined by 23.48 each month before the guideline release and by 56.74 per month afterwards. Before the CDC guideline, several opioid prescribing practices were decreasing. However, the time of its release was related to a greater decline. In changing prescribing practices, guidelines might be effective.