“…Also noteworthy, a recent Berlin-wide anonymous survey of patients under opioid services found that approximately 40% of those on conventional maintenance would prefer to transfer into diamorphine substitution (Bald, Bermpohl, Heinz, Gallinat & Gutwinski, 2013). Importantly, despite a higher opioid dose in terms of 'methadone equivalents', these patients reported more frequent use of illicit drugs than patients not desiring to switch to diamorphine maintenance therapy (Bald, Bermpohl, Heinz, Gallinat & Gutwinski, 2013). Finally, a positive association between patient satisfaction during methadone replacement therapy and treatment retention has been demonstrated, highlighting the great clinical relevance of this variable (Kelly, O'Grady, Mitchell, Brown & Schwartz, 2011).…”