“…All the studies included are randomized clinical trials (RCTs), but 10 studies included in the review on bMethadone Maintenance at Different Dosages for Opioid DependenceQ (Faggiano et al, 2003) are controlled perspective studies (CPS) (Caplehorn & Bell, 1991;Caplehorn, Dalton, Cluff, & Petrenas, 1994;Caplehorn, Irwig, & Saunders, 1996;D'Ippoliti, Davoli, Perucci, Pasqualini, & Bargagli, 1998;Del Rio, Mino, & Perneger, 1997;Gaughwin, Solomon, & Ali, 1998;Gossop, Marsden, Stewart, & Treacy, 2001;Maddux, Prihoda, & Vogtsberger, 1997;Torrens, Castillo, & Pérez-Solà, 1996;Van Ameijden, Langendam, & Coutinho, 1999). The analysis of CPS is presented separately from the others.…”