To estimate prevalence and persistence of 19 common paediatric conditions from infancy to 14–15 years.Design
Population-based prospective cohort study.Setting
Parallel cohorts assessed biennially from 2004 to 2014 from ages 0–1 and 4–5 years to 10–11 and 14–15 years, respectively, in the Longitudinal Study of Australian Children.Main outcome measures
19 health conditions: 17 parent-reported, 2 (overweight/obesity, obesity) directly assessed. Two general measures: health status, special health care needs. Analysis: (1) prevalence estimated in 2-year age-bands and (2) persistence rates calculated at each subsequent time point for each condition among affected children.Results
10 090 children participated in Wave 1 and 6717 in all waves. From age 2, more than 60% of children were experiencing at least one health condition at any age. Distinct prevalence patterns by age-bands comprised eight conditions that steadily rose (overweight/obesity, obesity, injury, anxiety/depression, frequent headaches, abdominal pain, autism spectrum disorder, attention-deficit hyperactivity disorder). Six conditions fell with age (eczema, sleep problems, day-wetting, soiling, constipation, recurrent tonsillitis), three remained stable (asthma, diabetes, epilepsy) and two peaked in mid-childhood (dental decay, recurrent ear infections). Conditions were more likely to persist if present for 2 years; persistence was especially high for obesity beyond 6–7 (91.3%–95.1% persisting at 14–15).Conclusions
Beyond infancy, most Australian children are experiencing at least one ongoing health condition at any given time. This study’s age-specific estimates of prevalence and persistence should assist families and clinicians to plan care. Conditions showing little resolution (obesity, asthma, attention-deficit hyperactivity disorder) require long-term planning and management.