Alcohol use, cigarette smoking, vaping and number of sexual partners: A cross‐sectional study of sexually active, ethnically diverse, inner city adolescents

Abstract Context There are few UK data on the prevalence and clustering of risky behaviours in ethnically diverse adolescents. Objectives To investigate the prevalence of reported alcohol use, smoking and vaping, and explore whether these behaviours are associated with increased numbers of sexual partners. Design Questionnaire survey of ‘Test n Treat’ chlamydia screening trial participants. Setting and participants Sexually active students attending six London technical colleges completed confidential questionnaires and provided genitourinary samples. Results The median age of the 509 participants was 17 years (IQR: 16‐18), 47% were male, 50% were of black ethnicity, 55% reported ≥2 sexual partners in the past year (67% of males and 45% of females) and 6.2% had chlamydia infection and 0.6% gonorrhoea. Almost half (48%) reported getting drunk in the past month, 33% smoked cigarettes and 7% had ever vaped. A larger percentage of students with ≥2 sexual partners than 0‐1 partners reported getting drunk in the past month (53.7%, 144/268% versus 42.2% 94/223, adjusted prevalence ratio: 1.33, 95% confidence interval: 1.11‐1.61) and smoking cigarettes (36.6%, 100/273% versus 30.2%, 67/222, 1.34 (1.05‐1.70)). By contrast, multiple sexual partners were not associated with vaping or chlamydia infection, but numbers were small. Conclusions We found high prevalences of risky behaviour and an association between multiple sexual partners and smoking and/or getting drunk. Findings support the introduction of compulsory sex and relationship education in UK secondary schools, including information about the adverse effects of alcohol and smoking. Public contribution Participants helped with study design, conduct and interpretation.