Relationship between life habits and school grades in adolescents

Background: Several studies have shown that academic performance in adolescents is closely related to alcohol intake, smoking, and the number of hours spent watching television. The aim of the present study was to determine the association between the time spent watching television, smoking and alcohol intake with academic grades in adolescents in Majorca (Spain). Methods: Data on sports activity, alcohol intake, smoking, the number of hours spent watching television and the number of subjects failed in the previous academic year were collected from 7,361 secondary school students aged 13-15 years old. The family's socioeconomic position was determined by data provided by the adolescents' parents. Multivariate analysis was used to identify the variables associated with a greater risk of failure. Results: The variables significantly associated with academic problems were smoking (OR = 2.64; 95% CI: 2.17-3.20), alcohol intake (OR = 1.58; 95% CI: 1.34-1.87), watching more than two hours of television per day (OR = 1.42; 95% CI: 1.19-1.69), coming from a family with a low socioeconomic position (OR = 5.72; 95% CI: 3.74-8.73), and older age (OR = 1.23; 95% CI: 1.16-1.31). The variables positively associated with good academic performance were practising sports at competition level (OR = 0.648; 95% CI: 0.594-0.787), taking part in sports more than twice a week (OR = 0.820; 95% CI: 0.712-0.945), and female sex (OR = 0.422; 95% CI: 0.373-0.477). Conclusions: Among Spanish adolescents, smoking, drinking alcohol, older age, male sex, watching television for more than two hours per day, and low socioeconomic position were closely related to academic failure. Practising sport more than twice a week was associated with better academic performance.