Has increasing internet use due to smartphone uptake contributed to the decline in adolescent smoking?

Abstract

The emergence of low-cost smartphone technology has coincided with major declines in adolescent smoking and other risk behaviours. This study explores the relationship between internet use and smoking in adolescents and investigates whether rising internet use contributed to the decline in smoking between 2012 and 2018. Data were drawn from a nationally representative New Zealand survey of students aged 14-15 (N=11 299), conducted biennially between 2012 and 2018. We used logistic regression to explore the association between internet use and smoking and test whether increasing time on the internet was associated with declining adolescent smoking over the study period. The proportion of students spending 5+ hours per day online increased from 15% to 35%. Heavy internet use was not a protective factor for smoking at the individual level. In 2016/2018, some types of past week internet use were associated with decreased risk of smoking (e.g. doing schoolwork, finding out about news), some were associated with increased risk (e.g. social media use) and others appeared to have no association with smoking (e.g. gaming, online shopping). The relative risk of smoking was lower in 2018 relative to 2012 (relative risk 0.68, 95% confidence interval 0.51, 0.90, after adjustment for demographic factors). Adding internet use to the model did not help to account for smoking decline. We found no evidence that increasing time spent on the internet during the 2012-2018 period (during which smartphones became ubiquitous) contributed to the decline in adolescent smoking.