Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder whose core symptoms are inattentiveness, hyperactivity and impulsivity. Usually considered a disorder of childhood and adolescence, ADHD is also present in approximately 3% of UK adults. Adults with ADHD tend to have lower educational attainment, reduced employment status and work performance, poor marital relationships, impaired driving safety and premature death from accidents and suicide. Such traits of ADHD, if left undiagnosed or unmanaged by treatment, can present a considerable burden on healthcare and community resource use. Yet, ADHD in adults is under recognised, it can take considerable time and resource until final diagnosis is made, which is further complicated by frequent co-occurrences of other psychiatric disorders.
This study aims to evaluate the real-world diagnostic journey including healthcare resource use (HCRU) and costs for adults before and after final diagnosis of adult ADHD in England. HCRU will include general practitioner appointments, referrals to specialists including mental health professionals, outpatient visits, accident and emergency visits and inpatient hospitalisations. Prescribed pharmacological and non-pharmacological treatments will also be included and overall costs will be calculated.
By comparing pre- and post-diagnosis HCRU and associated costs we aim to investigate the burden of treating un-diagnosed adult ADHD patients within England's healthcare system. Previous research has traditionally focused on HCRU of patients post ADHD diagnosis. Filling evidence gaps in the HCRU burden of adult ADHD patients prior to final diagnosis may demonstrate unmet need in the diagnostic journey of adult ADHD patients in England.
This is a retrospective cohort study to describe total healthcare resource use (HCRU) including costs of adult attention deficit hyperactivity disorder (ADHD) patients prior to diagnosis and post diagnosis in England. The study comprises an observation period from 2014 to 2019 and includes all patients aged 18+ years at study start and with an ADHD diagnosis (index date) between 2016 and 2018 (index period), a minimum of 18-months of data available before and after index date and without a history of ADHD including indicated-medication use prior to index date.
Study objectives include the evaluation of HCRU and associated costs in the 18-month period prior to the index date and comparing to those in the 18-month period after the index date. Diagnostic pathways of ADHD and post-diagnosis treatment patterns will also be assessed. Using CPRD-HES linked data, the healthcare records encompass both primary and secondary care and HCRU includes general practitioner appointments, referrals to specialists including mental health professionals, outpatient visits, investigations, A&E visits and inpatient hospitalisations, as well as prescribed pharmacological and non-pharmacological treatments. Costs will be grouped into prescription costs, primary health care consultations, investigations, outpatient appointments and hospital admissions. Patients’ characteristics at index date, such as age and gender, deprivation, comorbidities and region will also be evaluated.
The analysis comprises a description of HCRU and associated total costs in the pre and post index periods and a comparison using descriptive statistical measures for categorical and continuous variables as appropriate. Costs will also be compared using statistical tests.
In addition, the outcomes will be evaluated for the subgroups a) patients managed under the NICE CG72 and b) under NICE NG87 guidelines. In addition, secondary healthcare visits (inpatient, outpatient and A&E) will be grouped into mental disorders, accidents and injuries, and all other conditions.
Total HCRU including costs in ADHD patients within 18-months prior to diagnosis and total HCRU including costs within 18-months following diagnosis.
Sarah Jenner - Chief Investigator - IQVIA Ltd ( UK )
Emily Wilkes - Corresponding Applicant - IQVIA Ltd ( UK )
Lorena Cirneanu - Collaborator - IQVIA Ltd ( UK )
Margherita Bortolini - Collaborator - IQVIA Ltd ( UK )
Marios Adamou - Collaborator - Not from an Organisation
Peter Egger - Collaborator - IQVIA Ltd ( UK )
Sarah Jenner - Collaborator - IQVIA Ltd ( UK )
Gianluca Lucrezi - Collaborator - IQVIA AG (Switzerland)
Lorena Cirneanu - Collaborator - IQVIA Ltd ( UK )
HES Accident and Emergency;HES Admitted Patient Care;HES Outpatient;Patient Level Index of Multiple Deprivation