A 29-year-old male with alcohol use disorder has been participating in weekly motivational interviewing sessions for the past 10 weeks. At the outset of treatment, he was in the contemplation stage of change, drinking 8-10 standard drinks daily, and expressed ambivalence about reducing his alcohol use. At his current evaluation session, he reports he has reduced drinking to 3-4 drinks on weekends only, has attended two AA meetings, and has told his family he wants to stop drinking entirely. His AUDIT score has decreased from 32 to 14. However, he had one episode of heavy drinking two weeks ago during a stressful work event. The PMHNP is evaluating the effectiveness of motivational interviewing in this case. Which of the following best represents the appropriate outcome evaluation?