Self-medication among adolescents aged 18 years: the 1993 Pelotas (Brazil) birth cohort study

To estimate the point prevalence of self-medication among adolescents aged 18 years and to evaluate the type of drugs used (either over-the-counter or prescription drugs) and socioeconomic, health-related, and behavioral correlates of self-medication.

This cross-sectional study used data from the 1993 Pelotas (Brazil) Birth Cohort Study. Data were obtained through the administration of a questionnaire to adolescents aged 18 years. The outcome variables were point prevalence of medicine use and self-medication collected by self-report. The independent variables studied were gender, continuous medicine use, socioeconomic status, schooling, self-rated health, body mass index, and physical activity levels. Medicines were classified into therapeutic groups according to the Anatomical Therapeutic Chemical classification system.

A total of 4,106 adolescents were interviewed. The point prevalence of medicine use was 41.1% (95% confidence interval [CI] 39.6-42.6), and the proportion of self-medication among medicine users was 65.1% (95% CI 62.8-67.4). The point prevalence of self-medication was 26.7% (95% CI 25.4-28.1), and it was higher among female adolescents, those more educated, and those who rated their health as poor. Out of the drugs used for self-medication (58% of all drugs used), 1,003 (78.7%) were nonprescription drugs and 271 (21.3%) were prescription drugs. The most frequently used drugs for self-medication were analgesics (56.1%), systemic antihistamines (7.4%), and anti-inflammatory and antirheumatic products (7.1%).

A high point prevalence of self-medication was found among adolescents, which is particularly concerning due to high use of prescription drugs for self-medication. Interventions are needed to promote rational use of medicines in this population.