Article Text

Clustering of substance use and sexual risk behaviour in adolescence: analysis of two cohort studies


Objectives The authors aimed to examine whether changes in health risk behaviour rates alter the relationships between behaviours during adolescence, by comparing clustering of risk behaviours at different time points.

Design Comparison of two cohort studies, the Twenty-07 Study (‘earlier cohort’, surveyed in 1987 and 1990) and the 11-16/16+ Study (‘later cohort’, surveyed 1999 and 2003).

Setting Central Clydeside Conurbation around Glasgow City.

Participants Young people who participated in the Twenty-07 and 11-16/16+ studies at ages 15 and 18–19.

Primary and secondary outcomes measures The authors analysed data on risk behaviours in both early adolescence (started smoking prior to age 14, monthly drinking and ever used illicit drugs at age 15 and sexual intercourse prior to age 16) and late adolescence (age 18–19, current smoking, excessive drinking, ever used illicit drugs and multiple sexual partners) by gender and social class.

Results Drinking, illicit drug use and risky sexual behaviour (but not smoking) increased between the earlier and later cohort, especially among girls. The authors found strong associations between substance use and sexual risk behaviour during early and late adolescence, with few differences between cohorts, or by gender or social class. Adjusted ORs for associations between each substance and sexual risk behaviour were around 2.00. The only significant between-cohort difference was a stronger association between female early adolescent smoking and early sexual initiation in the later cohort. Also, relationships between illicit drug use and both early sexual initiation and multiple sexual partners in late adolescence were significantly stronger among girls than boys in the later cohort.

Conclusions Despite changes in rates, relationships between adolescent risk behaviours remain strong, irrespective of gender and social class. This indicates a need for improved risk behaviour prevention in young people, perhaps through a holistic approach, that addresses the broad shared determinants of various risk behaviours.

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  • To cite: Jackson C, Sweeting H, Haw S. Clustering of substance use and sexual risk behaviour in adolescence: analysis of two cohort studies. BMJ Open 2012;2:e000661. doi:10.1136/bmjopen-2011-000661

  • Contributors All authors contributed to the analysis plan and questions addressed in the paper and to the interpretation of the results. CJ drafted the paper and is guarantor. HS contributed to the design of 11-16/16+ and its data collection, cleaned data from both studies and conducted the analyses. HS and SH critically revised the paper and all authors gave approval for the final version to be published.

  • Funding CJ and SH are co-funded by the Scottish Chief Scientist Office and MRC at the Scottish Collaboration for Public Health Research and Policy (SCPHRP). HS is funded by the UK Medical Research Council (MRC) as part of the Gender and Health Programme (WBS U.1300.00.004) at the Social and Public Health Sciences Unit. The ‘Twenty-07’ and ‘11-16/16+’ studies were funded by the MRC. The analyses in the current study were part funded by a grant from the SCPHRP. The funders played no role in the design of the analysis and interpretation of the data, the writing of the report or the decision to submit the paper for publication.

  • Competing interests None.

  • Ethics approval Ethics approval was provided by NHS Scotland and Glasgow University.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data sharing statement

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