Table 3

 Characteristics of the interventions in the six “sound” trials

AuthorsIntervention nameIntervention typeIntervention objectivesSettingProviderLengthProtocol
Intervention groupControl group
Allen et al, 1997w1Teen OutreachYouth development programmeTo prevent teenage pregnancy and promote academic achievement among “high risk” young peopleSchool and communityTeachers and adult volunteersOne yearYoung people undertook nearly 50 hours of voluntary service in their local communities, reflected on their experiences in discussion groups, and attended social development classes.Young people in the control group received no intervention.
Berrueta-Clement et al, 1984w2The Perry Preschool ProgramEarly childhood interventionTo improve the intellectual and social development of children from socially disadvantaged familiesSchool and homeTeachersTwo yearsChildren received two and a half hours of preschool education five days a week during term time. Teachers made home visits one afternoon per fortnight.Children in the control group received no intervention.
Campbell et al, 2002w3The Abecedarian ProjectEarly childhood interventionTo enhance cognitive skills and “adaptive” behaviour in early childhood among children in “impoverished households”School and homeTeachersEight yearsChildren aged 0 to 4 years received full time day care that aimed to develop cognitive and language skills and adaptive behaviour. On entering school, children were assigned a home school resource teacher for three years to encourage parental involvement in learning.Children in the control group did not receive any educational intervention but they did receive nutritional supplements for the first 15 months of life.
Hahn et al, 1994w6The Quantum Opportunities ProgramYouth development programmeTo improve academic achievement and social skills among young people from families receiving public assistanceCommunityStaff from local Opportunities Industrial Centres (OIC)Four yearsYoung people took part in community improvement activities, educational activities (for example, tutoring), and developmental activities (for example, health education and career and college planning). Financial incentives were provided for participation.Young people in the control group received no intervention.
Hawkins et al, 1999w7The Seattle Social Development ProjectEarly childhood interventionTo increase school bonding and academic success, reduce physically aggressive behaviour, improve family behaviour management practices, and reduce poor health and other outcomes among children in schools serving high crime areasSchoolTeachersSix yearsTeachers were trained in classroom instruction and management and delivered a cognitive and social skills training curriculum. Parents were offered parent training classes to develop skills in child behaviour management, supporting their children to succeed at school, and reducing their children’s risks for using drugs.Children in the control group received no intervention.
Philliber et al, 2001w10The Children’s Aid Society Carrera-Model ProgramYouth development programmeTo reduce pregnancies amongst socially disadvantaged teenagersCommunityCommunity workersTwo to three yearsYoung people were offered academic support; health, sport, and art workshops; and participation in a “job club,” which included work experience and careers advice.Young people in the control group received no intervention.