title: Tracking of medicine use and self-medication from infancy to adolescence: 1993 Pelotas (Brazil) birth cohort study.
abstract: OBJECTIVE
  To track the use of medicine and self-medication from infancy to adolescence.
  
  
  METHODS
  All newborns in the city of Pelotas, Brazil, were monitored and enrolled in the 1993 Pelotas (Brazil) Birth Cohort Study. Subsamples of the cohort were visited at 1, 3, and 6 months and at 1 and 4 years of age. At 11 and 15 years of age, all cohort members were sought. In each of these visits, information on medicine use in the 15 days before the interview was collected. Two outcomes were analyzed: prevalence of medicine use and prevalence of self-medication.
  
  
  RESULTS
  Prevalence of medicine use in the first year of life ranged from 52.0% to 68.6%. From 4 to 15 years of age, the prevalence decreased, ranging from 30.9% to 37.2%. At age 15, girls presented a 33% higher prevalence of medicine use than boys. The proportion of self-medication ranged from 12.4% to 29.0% and was higher in girls aged 11 and 15 years than boys of the same age. In all follow-up periods, use of medicines was significantly higher among children who used medicines in the earlier period. Prevalence of self-medication was higher among those who were self-medicated in the previous periods.
  
  
  CONCLUSIONS
  Tracking studies are important to public health because they can predict future behavior by analyzing past behavior, thus helping in designing preventive actions. In this study, previous use of medicines predicts future use, thus creating an opportunity to plan actions that promote the rational use of medicines.
authors.affiliation: Postgraduate Program in Epidemiology, Federal University of Pelotas, Pelotas, Brazil. andreadamaso.epi@gmail.com
authors.forename: Andréa Dâmaso
authors.initials: AD
authors.lastname: Bertoldi
authors.forename: Marysabel Pinto Telis
authors.initials: MP
authors.lastname: Silveira
authors.forename: Ana M B
authors.initials: AM
authors.lastname: Menezes
authors.forename: Maria Cecília Formoso
authors.initials: MC
authors.lastname: Assunção
authors.forename: Helen
authors.initials: H
authors.lastname: Gonçalves
authors.forename: Pedro Curi
authors.initials: PC
authors.lastname: Hallal
mesh_terms: D000293:Adolescent; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D015438:Health Behavior; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D015995:Prevalence; D012651:Self Medication; D012737:Sex Factors