Use of healthcare services before diagnosis of attention-deficit/hyperactivity disorder: a population-based matched case-control study.
Level 4 - case-series / case-control
Population-based matched case-control study using electronic health records.
PubMed 37903632 · doi:10.1136/archdischild-2023-325637
What was done
A population-based matched case-control study analyzed linked primary care and hospital records from the English Clinical Practice Research Datalink (1998-2015). The study compared 8,127 children and young people (aged 4-17 years) diagnosed with ADHD against 40,136 non-ADHD controls matched on age, sex, and general practitioner (GP) practice. Medical diagnoses, prescriptions, hospital admissions, and procedures in the 2 years before diagnosis (or matched index date) were evaluated.
What was found
Children and young people with ADHD attended healthcare services twice as often as controls in the 2 years prior to diagnosis, with GP rate ratio 2.0 (95% CI: 2.0, 2.1) and hospital rate ratio 1.8 (95% CI: 1.8, 1.9). The strongest association for GP visits was for mental and behavioural disorders (OR 25.2, 95% CI: 23.3, 27.2). They also had higher attendances for physical conditions, including eye, ear, nose, throat, and oral conditions (OR 1.5, 95% CI: 1.4, 1.5), asthma (OR 1.3, 95% CI: 1.3, 1.4), and eczema (OR 1.2, 95% CI: 1.0, 1.3).
Why it matters
Children later diagnosed with ADHD present to healthcare services with elevated frequency for both physical and behavioural complaints years before formal diagnosis. These frequent contacts provide identifiable clinical opportunities for earlier recognition and intervention.
Limits
As an observational study using electronic health records, data are vulnerable to diagnostic misclassification, incomplete recording, and residual confounding. The retrospective case-control design cannot establish whether increased physical conditions reflect shared etiology, healthcare-seeking differences, or diagnostic bias. Results from English records between 1998 and 2015 may not fully reflect current practice or other healthcare settings.
Cited by
- contradicts Individuals with untreated ADD use medical services at four times the rate of the general population.