About the Study

The aims of the study have developed as the study has evolved to take account of the age and life-stage of the cohort members. They have also changed to take account of the data collection methods and data available for analysis. Across the eight phases of the study, the aims are outlined below

Phases 1 to 6 (age 12 to 17):

1. To investigate and identify the factors which impact on young people’s involvement in offending behaviour and desistance from it.

2. To examine the striking differences between males and females in terms of the extent and patterns of criminal offending.

3. To explore these in the contexts of:

• Individual development
• Interactions with official agencies of social control and law enforcement
• The social and physical structures of neighbourhoods

4. To develop new theories explaining offending behaviour and contribute to practical policies targeting young people.

Phase 7 (age 24):

5. To explore young people’s transitions from the juvenile justice system into the adult criminal justice system.

6. To identify the potential causal effects of juvenile justice system contact on later criminal conviction in adulthood.

Phase 8 (age 33):

7. To explore the impact of early contact with the justice system on the longer-term life chances of individuals (including health, employment, family and criminal conviction).

8. To compare the criminal justice profile of the Edinburgh Study cohort with the wider population across Scotland using administrative data.

The Edinburgh Study is a prospective longitudinal study involving a large, single-age cohort. The research includes a near total census of children who began secondary school in the City of Edinburgh in the autumn of 1998, at approximately age 12. This single-age cohort design was chosen over a multiple-cohort design as it was more efficient and would be less disruptive to schools, and could result in higher participation and response rates. The study followed the same year group on an annual basis for six years, by which point they had all reached the maximum school leaving age (approximately age 17). Subsequent follow-ups have taken place at age 24 and 33.

The study design includes multiple methods of data collection. The primary method of data collection during phases one to six was a self-completion questionnaire filled out by cohort members. Fieldwork during the first six phases was mainly carried out in supervised conditions at school; however, where this was not possible (due to absenteeism or leaving school) cohort members were contacted and (where possible) surveyed at another locus. Fieldwork carried out during phases 7 and 8 has mainly involved contacting cohort members at their home addresses and conducting either online, telephone or face to face interviews.

In addition to self-completion questionnaires, information has been sought about cohort members from a variety of administrative records, and linked using unique identifiers, in order to build up a broader picture of people’s lives. This has included data from: a survey of parents and carers (on home life and family relationships); school records (on school attendance, exclusion and attainment); social work records (on referrals to and contact with social workers); children’s hearings records (on referrals to the Children’s Reporter and attendance at children’s hearings); police records (on contact with juvenile liaison officers); and criminal history records (on number and nature of criminal convictions).

Cohort starting age: The Edinburgh Study of Youth Transitions and Crime was not concerned with identifying the childhood origins of criminal offending. Instead it aimed to explain differences in the pathways that young people take into and out of offending during their adolescent years (typically the ‘peak’ age of offending). For this reason, the study began by targeting young people who were starting their first year at secondary school (who were, on average, age 12) in the autumn of 1998.

Cohort location: The study focused on a single year cohort of young people attending school in the City of Edinburgh. This made it easier to negotiate with all the necessary schools and other organisations within one Local Authority. Rather than selecting a sample of young people from between or within schools (which would have been difficult to organise in practical terms and would weaken the power of the study during data analysis) a census approach was taken, with every school in Edinburgh being asked to participate. This provided a very strong research design for examining a range of various factors that drive offending behaviour, because the City of Edinburgh comprises enormous diversity, including all the extremes of poverty and wealth, high and low crime areas, and high and low areas of drug abuse.

School participation: In the first phase of the study, 40 out of a possible 49 schools in Edinburgh agreed to participate. This included all 23 mainstream secondary schools, 8 out of 14 independent schools and 9 out of 12 schools for children with special education needs. Pupils attending the participating schools represented 92.2% of all eligible children starting secondary school in 1998. All 40 participating schools took part throughout the first six phases of the study.

Parental participation: Parents were informed about the study by letter during the first year and asked if they wished to opt their child out of the study. A total of 151 children were opted out by their parents, reducing the proportion of all eligible children in the city to 89.1%. In phases two to six, parents of participating children were sent a reminder of the study and given the opportunity to opt their children out. Cohort members have also been given the opportunity to opt out at every study sweep.

Cohort participation in phase 1: The final eligible cohort in the first year of the study was 4,313. There was some cohort bias, given that the proportion of eligible participants from independent schools (60.5%) and special schools (65.3%) was far lower than the proportion attending mainstream secondary schools (96.8%). Given the small number of potential cohort members missed at special schools (around 30), it is unlikely to have had a dramatic effect on the overall findings of the study. However, excluding 39.5% (around 350) of the eligible independent sector pupils could have implications for the validity of the study when comparing across school sectors. Unfortunately, other than age, sex and school type, no information could be gathered on those who were not included in the first phase of the study.

Cohort participation in phases 2 to 4: All new pupils joining schools in the target year group up to the end of the third year of fieldwork were invited to participate in the study (the same parental opt in procedure was used). It was also decided that any pupils leaving the Edinburgh area altogether would not be tracked during years two and three (with the exception of those going to local authority funded special or residential schools outside Edinburgh). From year four onwards, it was agreed that there would be no further changes to the membership of the cohort. The final eligible cohort was set at 4,389.

Cohort response rates in phases 1 to 6: Cohort member response rates were extremely high in the first four years of the study (ages 12 to 15), mainly because the vast majority of the cohort were still attending school and could still be accessed fairly readily in class. However, once young people reached the school leaving age of 16, and school attendance began to fall, response rates fell in phases 5 and 6 as it became harder to contact individual cohort members. Nevertheless, in phase 6 the response rate was still over 80%, which is high for a longitudinal study.

Response rates at each sweep:

Notes: The final cohort was set at 4,389 in phase 4 (allowing no further participants to join the study). The number of ‘non-responders’ includes self and parental opt outs, people who had moved away, people who had died, people who refused to participate and people who could not be contacted despite multiple attempts.

Cohort participation in phase 7: Conducted in 2011/12, phase 7 of the study aimed to explore transitions into the adult criminal justice system at age 24 amongst the Edinburgh Study cohort. Criminal convictions data were updated from administrative records in order to study the characteristics and institutional histories of cohort members with a criminal record as compared to those with no record. A total of 4,243 eligible cohort members were known to be eligible to participate (i.e. based on a sample safeguarding exercise conducted in 2007 these individuals had not withdrawn from the study, died or moved away from the UK permanently). These cohort members were contacted by letter and given the opportunity to opt out of this phase of the study. As a result, records for 4,098 cohort members were checked and 511 (12.5%) of these individuals were found to have at least one criminal conviction.

In order to explore the impact of both early and late juvenile justice contact on longer term criminal justice transitions, two groups of young people were identified: one group who had experienced juvenile justice contact by the age of 12; and a second group who had experienced juvenile justice contact for the first time at age 15. Using a quasi-experimental design (propensity score matching) two matching control groups (who had not experienced juvenile justice contact) were identified based on data collected about all cohort members during phases one to six. A total of 463 individuals were selected for interview across all four groups (juvenile justice cases and their controls). Due to the very hard to reach nature of these groups, interviews were achieved with 252 (54%) of these individuals.

Cohort participation in phase 8: The main aim of phase 8 is to explore the impact of early justice system contact (both juvenile and adult) on people’s life outcomes at age 33. This phase will draw on data from the earlier phases of the Edinburgh Study; and it will make comparisons between the Edinburgh Study cohort and the wider population, using data from the Scottish Offenders Index.

Phase 8 will involve a further update of the criminal conviction records for all cohort members; a short online survey of all cohort members; and face-to-face interviews with a sub-sample of around 200 cohort members. Fieldwork for phase 8 is just beginning, so further details will be provided once this has been completed.

Further information on participation rates can be found in the Edinburgh Study technical reports, available in the Publications section of this website.

Further information on the characteristics of the cohort during years 1 and 2 can be found in chapter 2 of Smith et al., (2001) The Edinburgh Study of Youth Transitions and Crime: Key Findings at Ages 12 and 13.

The consent procedures for this study were carefully discussed and agreed by the Edinburgh Study Advisory Group, chaired by Professor Sir Michael Rutter and attended by senior members of all relevant organisations from the City of Edinburgh.

During phases one to three, the parents of all young people in the relevant year group who were attending participating schools were sent a letter explaining what the study was about, what it would involve and the type of information that would be collected. This letter provided detailed information about our plans to access administrative records, including social work, children’s hearing, and school records. Parents were given the opportunity to opt their child out of the research at this initial stage. Prior to the start of fieldwork in phase one, 151 young people were permanently opted-out of the study by their parents. Once young people had been enrolled into the study, parents were sent a letter at each further phase of data collection to remind them about the study and give them a further opportunity to withdraw their child.

All cohort members have been given the opportunity to opt out of the research at every phase of the study.

In 2001, written consent to access Juvenile Liaison Officer records was gained from cohort members at phase four of the study (3,447 individuals provided consent). In 2006 and 2011, all contactable cohort members were sent information about plans to collect and update data from criminal records and given the opportunity to opt out of these phases of data collection. In 2019, all cohort members will again be written to about criminal convictions data collection and giving them the opportunity to opt out.

The Edinburgh Study research team has provided a complete guarantee of confidentiality to all cohort members at every phase of data collection. This applies to all information collected, including personal contact details, self-completion questionnaire responses and information collected from administrative records, such as social work, school, children’s hearings and criminal conviction records. Moreover, no member of the cohort has ever been identified or asked to participate in any media or promotional work relating to the study.

Until phase six of the study there was one exception to the guarantee of confidentiality. It was agreed by the Study Team with the City of Edinburgh Council Child Protection officer that any disclosures of physical or sexual abuse would be reported to the school authorities; however, no such disclosures were ever made.

Our first priority is to ensure that the Edinburgh Study is conducted safely and that any data collected is held securely. As data held by the Edinburgh Study are personal data, they are subject to the Data Protection Act 2018 and the General Data Protection Regulation of the EU. Ethical approval for the study has been granted at each phase of fieldwork by the University of Edinburgh’s School of Law Research Ethics Committee.

A Data Protection Impact Assessment (DPIA) was conducted and approved by the University of Edinburgh’s Data Protection Officer on 23rd July 2019. The DPIA provides that all study data will be held on the University’s secure Datastore system which has strict security measures in place to prevent unauthorised access to file servers. Data will be held in folders that can be authorised only by approved users (members of the study team). There is restricted access to the databases holding personal data (names, dates of birth, addresses, telephone numbers, etc) which are held only for cohort contact and data linkage purposes. All folders are password protected.

Any personal data held on paper records are kept secure in locked cabinets and in locked rooms. Only restricted members of the study team will have access to these cabinets. Researchers have access to only the information necessary to conduct their fieldwork. While conducting fieldwork, personal data will only be accessible via tablets carried by the researchers, which will be password protected and encrypted.

Data transfer on criminal convictions data will take place through a secure data transfer service, operated as standard by Police Scotland. All those with access to personal data collected through the Edinburgh Study are subject to strict protocols as to how they can use and access the data. No information collected about study members is passed on to Police Scotland during administrative data collection.

Any information published from the study will be presented at an aggregate level and will not allow any individual to be identified, either directly or indirectly. As is standard for publicly funded academic research, data collected by the study may be shared, but only in an anonymised form, to allow reuse by other researchers (e.g. through the UK Data Archive). However, special procedures are put in place to restrict access to these anonymised data and they will always be released in a format that does not allow any individuals to be identified.