Simkiss 2013.

Methods	Design: Parallel randomised controlled trial Unit of randomisation: Individual family Follow‐up: 9 months Study dates: December 2008 to January 2011
Participants	Participants: Parents (275 mothers; 11 father) living in the catchment area of "Flying Start" early years centres who had not previously attended the Family Links Nurturing Programme Mean age of parents: Not reported Age of child: 2 to 4 years (mean, SD, range, number of boys and girls: NR) Ethnicity: 71% White British; 16% White Other; 1% Black African; 0.3% Black Caribbean; 5% Asian Indian/Pakistani/Bangladeshi; 0.7% Asian Chinese; 6% other Number randomised: 286 (intervention 143; control 143) Country & setting: UK; multi‐site; recruited from early years' centres; delivery of intervention not reported Eligibility criteria: Parents with children aged 2 to 4 years living in the catchment area of ‘Flying Start’ early years centres who had not previously attended a Family Links Nuturing Programme
Interventions	Two conditions: Group‐based parent training (Family Links Nurturing Programme); wait‐list control Duration of intervention: 10 (2 hour) sessions over 10 weeks Therapist training: Facilitators trained over a 4‐day programme and had supervision
Outcomes	Externalising problems: Parent Account of Child Symptoms ‐ Cscale, as reported by researchers observing child behaviour Externalising problems subscales ‐ hyperactivity/inattention: Parent Account of Child Symptoms ‐ Hscale, as reported by researchers observing child behaviour Internalising problems: Parent Account of Child Symptoms ‐ internalising, as reported by researchers observing child behaviour. We included data from the Hscale and Cscales, but have requested confirmation from the study investigators that these scales represent hyperactivity and conduct. No further information was available at the time this review was prepared Timing of outcomes: Outcomes reported for 9‐month follow‐up Secondary outcomes/adverse events: No other outcomes relevant to this review specified
Notes	Level of prevention: Primary Funding: Trial was funded by a consortium of four local authorities in South Wales: Cardiff, Torfaen, Newport and Caerphilly and the Welsh Assembly Government. Additional funding was provided by the Esme Fairburn Foundation and the Waterloo Foundation
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	A random sequence was computer‐generated
Allocation concealment (selection bias)	Low risk	Study investigators reported that the allocation sequence was held by a service not involved with recruitment, therapy, or evaluation
Blinding of participants and personnel (performance bias) All outcomes	High risk	Participants: It would not have been possible to fully blind participants in this type of study (there is an obvious difference between receiving group training and wait list). No indication of any specific additional measures taken to reduce the risk of bias that might result from differential behaviours by participants were found Personnel: The design of the study meant that personnel delivering the intervention were aware which groups had been assigned to the different study conditions
Blinding of outcome assessment (detection bias) Independent observer reported outcomes	Low risk	Study investigators reported that assessors conducting coding and data analysis were blind to group allocation, "except on rare occasions when families disclosed their assignment status during postcourse interviews"
Blinding of outcome assessment (detection bias) Parent reported outcomes	Low risk	There were no parent‐reported outcome measures
Incomplete outcome data (attrition bias) All outcomes	High risk	The study reported that 48/143 families (34%) allocated to the intervention group did not attend any sessions; a further 27/143 (19%) discontinued the programme in the first 3 sessions. Reasons for dropout not given. 15/143 (10%) control group families attended a Family Links Nurturing Programme before 9‐month follow‐up and a further 13/143 (9%) control group parents attended other parenting support programmes during the trial. Number of analysed participants does not match with these numbers
Selective reporting (reporting bias)	Low risk	The published report included all expected outcomes, including those that were prespecified
Other bias	Low risk	The study appeared to be free of other sources of bias