Scottish Schools Adolescent Lifestyle and Substance Use Survey (SALSUS): technical report 2018

Comparisons with previous data

As is shown in Table 4 below, the age range for 2018 was in keeping with 2015. When analysing the long term trends, it is important to bear in mind that the 2002 and 2004 cohorts were older than those in 2006-15 (as the survey was conducted later in the school year in 2002 and 2004).^[14] Previous surveys show that age plays an important role in the incidence of smoking, drinking and drug use.

Table 4: Age profile comparison between 2015 and 2018

In the surveys conducted prior to 2002, substance use prevalence was measured at a UK level. In order to allow comparability across the home nations (i.e. different age cut-offs for otherwise equivalent year groups), findings were analysed by differences in pupil age rather than year groups. Where comparisons with earlier surveys are made, therefore, S2 and S4 pupils from SALSUS 2018 are compared with 13 year olds and 15 year olds respectively. For simplicity, S2 pupils are referred to as '13 year olds' and S4 pupils as '15 year olds' throughout the report.