Time trends in autism diagnosis over 20 years: a UK population-based cohort study
Abstract
BACKGROUND
Autism spectrum disorder is a diagnosis that is increasingly applied; however, previous studies have conflicting findings whether rates of diagnosis rates continue to grow in the UK. This study tested whether the proportion of people receiving a new autism diagnosis has been increasing over a twenty-year period, both overall and by subgroups.
METHOD
Population-based study utilizing the Clinical Practice Research Datalink (CPRD) primary care database, which contains patients registered with practices contributing data to the CPRD between 1998 and 2018 (N = 6,786,212 in 1998 to N = 9,594,598 in 2018). 65,665 patients had a diagnosis of autism recorded in 2018. Time trend of new (incident) cases of autism diagnosis was plotted for all, and stratified by gender, diagnostic subtypes, and developmental stage: infancy and preschool, 0-5 years old; childhood, 6-11 years old; adolescence, 12-19 years old; adults, over 19 years old.
RESULTS
There was a 787%, exponential increase in recorded incidence of autism diagnoses between 1998 and 2018; R2 = 0.98, exponentiated coefficient = 1.07, 95% CI [1.06, 1.08], p < .001. The increase in diagnoses was greater for females than males (exponentiated interaction coefficient = 1.02, 95% CI [1.01, 1.03], p < .001) and moderated by age band, with the greatest rises in diagnostic incidence among adults (exponentiated interaction coefficient = 1.06, 95% CI [1.04, 1.07], p < .001).
CONCLUSIONS
Increases could be due to growth in…
How strong is the evidence?
Evidence Hub reads this as a cohort study, done in people. Its evidence level is 3 of 5 (Moderate · trial / cohort / secondary analysis). Trials without a large randomized design, cohorts and secondary analyses give moderate evidence. Reported size: 9,594,598 participants or records.
Read the paper
Related studies
- Improving sleep quality leads to better mental health: A meta-analysis of randomised controlled trials
- Community transmission and viral load kinetics of the SARS-CoV-2 delta (B.1.617.2) variant in vaccinated and unvaccinated individuals in the UK: a prospective, longitudinal, cohort study
- Occupation and risk of severe COVID-19: prospective cohort study of 120,075 UK Biobank participants
- Clinical presentation and virological assessment of confirmed human monkeypox virus cases in Spain: a prospective observational cohort study
- Comparison of the characteristics, morbidity, and mortality of COVID-19 and seasonal influenza: a nationwide, population-based retrospective cohort study
- Lifestyle risk factors, inflammatory mechanisms, and COVID-19 hospitalization: A community-based cohort study of 387,109 adults in UK
Go deeper in Evidence Hub
Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.