Aims: To examine how adolescents' inattentive behaviour, together with parental smoking patterns, predicts smoking initiation by age 14. DESIGN, SETTINGS: A prospective, longitudinal study: baseline at ages 11-12, follow-up at age 14. A population-based sample of Finnish twins, born 1983-1987, with parents and classroom teachers as additional informants. Two groups were formed, allocating the co-twins of each family into separate groups: the study sample and a replication sample.
Participants: Twin individuals (n = 4552), aged 11-12 at baseline and 14 (average 14.04 years) at follow-up.
Measurements: At baseline, inattentiveness was assessed with the Multidimensional Peer Nomination Inventory (MPNI, Teacher Form) and parental smoking with individual questionnaires completed by each twins' parents; at the age 14 follow-up, adolescent smoking was assessed with a self-report questionnaire.
Findings: At age 14, 57% reported never having smoked, 34% had experimented with cigarettes and 9% were current smokers. Inattentiveness and parental smoking additively predicted both experimental and current smoking in adolescence. The effects were independent of each other.
Conclusions: The risk related to inattentiveness itself is high, but in combination with the effects of parental smoking, the probability of current smoking can rise as high as 38%, compared with 5% without these two risk factors. For prevention purposes, parental commitment to non-smoking should be emphasized.