This is the most recent survey in a series that began in 1982. Each survey since 1998 has included a core set of questions on smoking, drinking and drug use. In 2000, the survey questions changed to focus on smoking and drinking or on drug use in alternate years and in 2016, the survey reverted back to including both drinking/smoking and drugs focused questions in one survey.
The 2018 survey was conducted by Ipsos Mori, and questioned 13,664 year 7 to 11 pupils, mostly aged 11 to 15, from 193 schools across England, between September 2018 and February 2019.
Full details of the survey design and data collection are given in the Appendix to this report.
Each survey now includes a core section of questions covering the following:
- pupils’ experience of smoking, drinking and drug use;
- consumption of cigarettes and alcoholic drinks in the last week;
- awareness and availability of specific named drugs; and
- small sections on wellbeing and family affluence
More detailed questions were also asked but the sample was split in two in order to make it possible for pupils to complete the questionnaire in one school period. Half the pupils were asked additional questions on smoking and drinking and the other half were asked additional questions on drug use. The additional questions included:
- where pupils get cigarettes, alcohol and drugs;
- attitudes of pupils and their families to smoking, drinking and drug taking;
- impact of school lessons and other sources of information about smoking, drinking and drug taking. dependence on smoking;
- exposure to second-hand smoke;
- where and with whom pupils drink;
- experience of drunkenness; and
- types of drugs taken.
Estimates from surveys
This survey, in common with other surveys, collects information from a sample of the population. The sample is designed to represent the whole population as accurately as possible within practical constraints, such as time and cost. Consequently, statistics based on the survey are estimates, rather than precise figures, and are subject to a margin of error, also known as a 95% confidence interval. Section 2 of Appendix B shows how sampling errors were calculated.
For example the survey estimate might be 24% with a 95% confidence interval of 22% to 26%. A different sample might have given a different estimate, but we expect that the true value of the statistic in the population would be within the range given by the 95% confidence interval in 95 cases out of 100. Confidence intervals are affected by the size of the sample on which the estimate is based. In general, the larger the sample, the smaller the confidence interval, and hence the more precise the estimate.
For key measures in this report, the confidence intervals have been quoted in brackets after the estimated prevalence. Confidence intervals for other key survey estimates are available in an Excel appendix table that accompanies this report.
Where differences are commented on, these reflect the same degree of certainty that these differences are real, and not just within the margins of sampling error. These differences can be described as statistically significant, implying no more than a 5% chance that any reported difference is not a real one but a consequence of sampling error. Some apparently large differences which are not statistically significant have been annotated in the report so users are aware of this.
