Hucker 1988.

Methods	Design: parallel RCT
Participants	Participants: paedophiles currently charged with a sexual offence against children or convicted of such an offence in the past and instructed to take treatment as a condition of probation Sex: male Age: mean = 40.5 years. No SD or range given Unit of allocation: individual Number randomised: 18 Number completing: 11 Setting: the Forensic Service of the Clarke Institute (Toronto, Canada) Inclusion criteria: primary attraction to children Exclusion criteria: suffering from any medical condition that would "contraindicate participation" (p 230) Baseline characteristics: data provided on IQ scores (mean = 106.7; education (mean years completed = 12.2), and number of previous sex offences (mean = 1.7). 2 neuropsychological tests and a phallometric test to confirm sexual preference for children were also administered.  Alcohol and drug use data were collected and reported (p 230, p 233)
Interventions	2 conditions: medroxyprogesterone acetate (MPA) (200 mg/day) placebo (described as identical in colour and taste) Both interventions administered orally Duration of trial: 3 months Length of follow‐up: none past end of study
Outcomes	Primary outcome Recidivism as measured by reconviction, caution or self report: no data reported Secondary outcomes  Capacity for physiological arousal: number of erections, sexual activity (masturbation or intercourse) Anomalous or deviant urges or desires: frequency of sexual fantasies (participants in this trial were all paedophiles. Fantasies were subdivided into those about adults and those about children) Anxiety or mood: anecdotally reported; potentially artefacts of distress whilst awaiting trial Dropping out of treatment: (see note 1) Adverse events: side effects of medroxyprogesterone Other outcomes Hormone profiles: plasma testosterone levels; metabolites; liver enzymes
Notes	Investigators note that refusal rate for therapy is as important as the rate of dropout (citing Langevin 1979). For this study (for example) of "100 consecutive referred cases, only 48 were prepared to complete a comprehensive assessment, consider treatment, or even admit they might have a problem of sexual attraction to children" (p 231)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomisation was done at a pharmacy; method of sequence generation unknown (Hucker 2012)
Allocation concealment (selection bias)	Low risk	Investigator clarified that the preparation of both treatment and placebo was done remotely and in batches by the pharmacy involved. Treating staff were unaware of allocation (Hucker 2012)
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Neither participants nor their treating physicians were aware of assignment throughout the study (Hucker 2012)
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Neither participants nor their treating physicians were aware of assignment throughout the study at outcome assessment (Hucker 2012)
Incomplete outcome data (attrition bias) All outcomes	High risk	1 participant was excluded from the study due to a medical condition (parathyroid tumour). A second was excluded from analysis as hormone analysis showed he was not taking the MPA. 5 participants left of their own accord; these men appeared to have had "higher frequency of fantasies about children" (p 234); investigators themselves were unsure whether this might represent selection bias of a higher risk group unwilling or unable to give up fantasies about children
Selective reporting (reporting bias)	Low risk	Study protocol is not available but it seems clear that the published report included all expected outcomes, including those that were pre‐specified
Other bias	Low risk	The study appeared free of other sources of bias. The investigators made strenuous efforts to assess potential baseline differences between those choosing to participate in the study and those who did not and found, for example, those accepting had generally higher IQ scores. They also compared baseline data for those who dropped out and those who completed the study, and found no significant differences except on fantasies