Trends in Sexual Behaviors and Attitudes in the UK

We did all analyses with the complex survey functions of Stata (version 12.1) to incorporate weighting, clustering, and stratification of data. We present descriptive statistics by sex and age group. We used binary logistic regression to calculate age-adjusted odds ratios (aAORs) to investigate how reporting of key sexual behaviours and attitudes varied by three measures of social status: the National Statistics Socio-Economic Classification²⁸ (NS-SEC; individual level), education attainment defined according to school leaving age and academic qualifications obtained (individual level), and the Index of Multiple Deprivation²⁹ (area level). We then used ordinal and binary logistic regression to calculate aAORs to compare estimates between the three Natsal surveys for participants aged 16–44 years. We used Natsal-2 as the reference category to quantify the change between Natsal-2 and Natsal-3 and also to allow comparisons with Natsal-1. Finally, we obtained data from the three surveys to examine changes in the reporting of sexual practices with partners of the opposite sex and partner numbers by birth cohort and age at interview. We used an α of 0·05 in all analyses.