CCBH (B) 2002.

Methods	Allocation: randomised controlled trial; Randomization performed centrally; Blindness of the patients and or the care providers in respect to treatment: not performed, all the patients were orally informed about the treatment they had been allocated Duration of treatment within the study: 12 months
Participants	Diagnosis: heroin addicts (inhaling use) registered in the local methadone maintenance programs, who had failed several methadone programs. N=256 Age=39.6 (5.7 SD) Sex= 79.7% male; History=a history of heroin dependency (DSM‐IV) of at least five years; a minimum dose level of 50 mg (inhaling) or 60 mg (injecting) of methadone per day for an uninterrupted period of at least four week in the previous five years; in the previous year registered in a methadone program, and during the previous six months in regular contact with the methadone program; chronic heroin addiction and unsuccessfully treated in methadone maintenance treatment; daily or nearly daily use of illicit heroin; poor physical, and/or mental, and/or social functioning; Criminal activity=at study entrance at least six days in the previous month of drug‐related illegal activities Mental State= at study entrance a SCL‐90 total score of at least 41 (males) or 60 (females)
Interventions	Group A (no. = 139) 12 months methadone; Group B (no. = 117) 12 months heroin (inhalable) + methadone; Group C (n=119) 6months methadone+ 6 months Psychosocial interventions: Psychosocial treatment was offered throughout
Outcomes	Dichotomous, multidomain response index, including validated indicators of physical health, mental status, and social functioning. Information on Substance use; Retention in treatment, Death, Adverse events
Notes	Country: The Netherlands 1998‐2001 Website: www.ccbh.nl/ENG/publications.htm
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	no description of sequence generation could be traced in the articles and the report of the study and in agreement with the CDAG rule, the judgment has to be "unclear".
Allocation concealment (selection bias)	Low risk	"the randomization was organized centrally by an independent monitoring organization, and conducted separately for the trials on injectable heroin and inhalable heroin." Authors were contacted for further details and correspondence is available by the reviewer's author.
Incomplete outcome data (attrition bias) All outcomes	Low risk	"In the present study, it could not be ruled out that the probability of response would systematically and considerably differ between patients with and without endpoint‐assessments. However, since the primary analysis of effectiveness concerned the total treatment‐offer, regardless of possible deviations from the protocol, statistical methods to correct for bias in the findings caused by missing endpoint‐assessments, like multiple imputation or propensity score estimation, were only of limited applicability. It was therefore considered crucial to minimize the occurrence of missing endpoint‐assessments as much as possible, by conducting intensive field work and by providing additional financial compensation for participating in the endpoint‐assessments. Nevertheless it could not be excluded that some missing endpoint‐assessments would occur in the study population. In case of such missing endpoint‐assessments, and because of lack of satisfactory alternatives, the "last observation carried forward" (LOCF) method was used in the primary analysis."
Selective reporting (reporting bias)	Low risk	Yes prespecified outcomes available on the website of the study, details on table 3.
Blinding (objective outcomes: drop out, use of substances measured by urine analysis)	Low risk	In order to reduce the risk of information bias, outcome assessments were conducted by independent assessors, who used standardized instruments and evaluation procedures.
Blinding (subjective outcomes: use of substances as measured by self report, side effects)	Low risk	The validity of the self‐report data was checked through the application of urinalysis, with regard to the concurrent use of illicit drugs, and collection of registered data from the police and justice system, with regard to committed offenses and periods of detention. These latter types of data are insensitive to information bias.