Methods	Design: parallel randomised controlled trial
Participants	Participants: incarcerated drink-driving offenders with AsPD sentenced to a Driving While Intoxicated (DWI) treatment programme Sex: (AsPD subgroup) 45/52 (87%) male; 7/52 (13%) female Age: (AsPD subgroup) mean 26.5 (SD 7.9) years Unit of allocation: individual participant Number randomised: 52 (n = 36 intervention group; n = 16 control group) Number completing: 52 (n = 36 intervention group; n = 16 control group) Setting: prison, single site, USA (New Mexico) Inclusion criteria: court-defined first offenders sentenced to the Driving While Intoxicated (DWI) treatment programme whilst in prison; diagnosis of AsPD (DSM-III-R, Diagnostic Interview Schedule) Exclusion criteria: none reported Ethnicity: (AsPD subgroup) 37/52 (71%) Native American; 12/52 (23%) Non-Hispanic white; 3/52 (6%) Hispanic or other Baseline characteristics: 42/52 (89%) met DSM-III-R criteria for alcohol dependency using the Diagnostic Interview Schedule; mean DrinC score = 23.8 (SD 9.9); mean number of days drinking in past 30 days = 9.2 (SD 8.4) days; mean number of days in last 30 days when had drank and then driven = 3.9 (SD 5.3) days; mean number of drinks per drinking day = 5.9 (SD 5.1); mean number of days with 5 or more drinks = 5.9 (SD 6.9); mean number of days driving after 5 or more drinks = 2.9 (SD 4.3); Form 90 measures of drinking over past 90 days: total standard ethyl-alcohol consumption (SEC) = 328.0 (SD 431.3), drinking days = 25.7 (SD 26.3), mean blood alcohol content (BAC) = 0.043 (SD 0.058)
Interventions	Two conditions: ’Driving Whilst Intoxicated program’ + incarceration/incarceration only ’Driving Whilst Intoxicated program’ + incarceration (DWI) (n = 36 randomised) Incarceration only (n = 16 randomised) Details of conditions: In the DWI condition, the programme was non-confrontational and utilised motivational interviewing principles. Components included: alcohol use, abuse and dependence; health and nutrition; psychological effects of alcohol; drinking and driving awareness; stress management; goal setting and action planning for the future; family issues and alcohol; domestic violence; HIV/AIDS prevention; work release programme for those in employment. Also incorporated culturally appropriate elements such as sweat lodges and talking circles (71 % of participants were native American). The DWI programme was delivered whilst participants were subject to 28 days incarceration The control condition was 28 days incarceration Duration of intervention: 28 days Duration of trial: 25 months (1 month of intervention and 24 months of follow up) Length of follow up: 6, 12 and 24 months Dose adjustment: n/a
Outcomes	Primary outcomes Reconviction: recidivism data Secondary outcomes Substance misuse (alcohol): number of drinks, number of drinking days and mean blood alcohol content; mean number of days driving after drinking in past 30 days; mean number of days driving after 5 or more drinks in past 30 days (via Form 90 and DrInc-2R questionnaires) Other outcomes None
Notes	-
Risk of bias
Item	Authors’ judgement	Description
Adequate sequence generation?	Unclear	No information provided. Insufficient reporting to permit judgement of Yes or No. Clarification has been requested from the trial investigators, but no further information was available at the time this review was prepared
Allocation concealment?	Unclear	No information provided. Insufficient reporting to permit judgement of Yes or No. Clarification has been requested from the trial investigators, but no further information was available at the time this review was prepared
Blinding? of participants	Unclear	In a study such as this full blinding is difficult to achieve because participants would be aware whether or not they were participating in a psychological intervention and may also be aware of the nature of this intervention. The review authors judged that it would thus not be possible to fully blind participants in this type of study. We found no indication of any specific additional measures taken to reduce the risk of bias that might result from differential behaviours by participants
Blinding? of personnel	Unclear	In a study such as this full blinding is difficult to achieve because personnel would be aware whether or not they were participating in a psychological intervention and may also be aware of the nature of this intervention. The review authors judged that it would thus not be possible to fully blind personnel in this type of study
Blinding? of outcome assessors	Unclear	Insufficient information to allow a judgement to be made. Clarification about blinding of outcome assessors has been requested from the trial investigators, but no further information was available at the time this review was prepared
Incomplete outcome data addressed? All outcomes	Unclear	For the outcome of self-reported drink-driving behaviour, data missing for 6/36 (17%) of the intervention group and for 3/16 (19%) of control group. Although these numbers appear similar, reasons for this missing data are not provided. For the outcome of alcohol use, the amount of missing self-report data is not reported but review authors judge it reasonable to assume that the above figures also apply to this as it was measured similarly. For the outcome of drink-driving recidivism, it is unclear what numbers of missing data occurred in AsPD subgroup, although for entire sample missing data on this item reported as 31/305 (10%). Clarification has been requested from the trial investigators, but no further information was available at the time this review was prepared
Free of selective reporting?	Yes	Study protocol is not available but it seems clear that the published report includes all expected outcomes. No evidence of selective reporting. All prospectively stated outcomes are reported
Free of other bias?	Unclear	In terms of baseline imbalance, the intervention group were significantly more likely to have histories of drinking and driving in comparison with the controls, although it is unclear if this applied to the AsPD subgroup