METHODS	Using data from a multisite , randomized controlled trial of buprenorphine-naloxone plus counseling for DSM-IV prescription opioid dependence ( June 2006-July 2009 ) , we conducted a secondary analysis to investigate the relationship between initial medication response and 12-week treatment outcome to establish how soon the efficacy of buprenorphine-naloxone could be predicted ( N = 360 ) .\