Rosenblatt 1976.

Methods	Design: placebo‐controlled cross‐over trial
Participants	Participants: adults who had complained of difficulty in controlling physically punitive impulses towards (or were suspected of physical assault on) their own children Sex: mixed (11 women; 2 men) Age: adults, age not reported Unit of allocation: individual participant Number randomised: 13 (11 women; 2 men) (see note 1) Number completing: 8 completed phase 1 (6 women; 2 men) (see note 1) Setting: outpatient; USA (New York) Inclusion criteria: suspected of physical assault on (or complaining of difficulty in controlling physically punitive impulses towards) own children Exclusion criteria: not reported Ethnicity: not reported Baseline characteristics: not reported
Interventions	Two conditions: diphenylhydantoin / placebo diphenylhydantoin 400 mg/day; administered as 200 mg twice daily placebo Duration of intervention: 8 weeks Duration of trial: 16 weeks (cross‐over trial; 2 phases) Length of follow up: participants were not followed up beyond the end of the intervention period Dose adjustment: not reported
Outcomes	Primary outcomes None Secondary outcomes Aggressive impulsiveness: subscale of Q‐Sort A, a self‐rating scale (developed by the authors) Hostility: subscale of Q‐Sort A, a self‐rating scale (developed by the authors); subscale of Q‐Sort B, a self‐rating scale (developed by the authors) Non‐compliance: proportion of participants discontinuing treatment
Notes	1. n = 13 randomised, but information on number allocated to each intervention at start of trial was not provided. Results for phase 1 completers only (5 in diphenylhydantoin group; 3 in placebo group).
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Unclear risk	Investigators report that participants were allocated “on a random, double‐blind basis . . “ (p.333). No further details given. Due to age of study, unable to contact trial investigators for more information.
Allocation concealment?	Unclear risk	No details reported. Due to age of study, unable to contact trial investigators for more information.
Blinding? of participants	Unclear risk	Investigators report that participants were allocated “on a random, double‐blind basis . . “ (p.333). No further details given. Due to age of study, unable to contact trial investigators for more information.
Blinding? of personnel	Unclear risk	Investigators report that participants were allocated “on a random, double‐blind basis . . “ (p.333). No further details given. Due to age of study, unable to contact trial investigators for more information.
Blinding? of outcome assessors	Unclear risk	Investigators report that participants were allocated “on a random, double‐blind basis . . “ (p.333). No further details given. Due to age of study, unable to contact trial investigators for more information.
Incomplete outcome data addressed? All outcomes	Unclear risk	Investigators report attrition overall (5/13 in phase 1) but not by treatment condition. Insufficient reporting of attrition to permit judgement of ‘Yes’ or ‘No’. In this review, data from 8 participants were included in the analysis.
Free of selective reporting?	Low risk	Study protocol is not available but it seems clear that the published report includes all expected outcomes.
Free of other bias?	Unclear risk	Although this was a 16‐week cross‐over trial, results reported for first week only. Investigators report that after the first week of the trial, “confounding factors such as the interviews, changes in life situation etc., strongly influence the dependent variable”. Insufficient information to assess whether an important risk of bias exists.