Can Electronic Health Records Be Used to Study ADHD and Autism in Children?

What you need to know

• Electronic health records can be used to identify children with ADHD and autism and track their outcomes into early adulthood
• Children with ADHD or autism identified through health records showed expected increased risks for mental health problems, substance use, and self-harm in early adulthood
• Using electronic health records allows researchers to study large numbers of people with ADHD and autism over time without issues of participants dropping out

Background and Purpose

Attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) are conditions that typically start in childhood and can have long-lasting impacts. Studying how these conditions affect people over time is important, but can be challenging. Traditional research studies often have issues with participants dropping out over time, especially those with mental health conditions or from disadvantaged backgrounds. This can make the results less reliable.

An alternative approach is to use electronic health records to track large numbers of people over time. Wales, a country in the UK, has a comprehensive system called the SAIL (Secure Anonymised Information Linkage) Databank that links health records for the entire population.

This study aimed to see if researchers could use the SAIL Databank to:

1. Identify children diagnosed with ADHD and autism
2. Track their outcomes into early adulthood
3. Compare their outcomes to children without these diagnoses

The researchers wanted to validate this method of using electronic health records as a way to study ADHD and autism over time.

How the Study Worked

The researchers used data from the SAIL Databank on all individuals in Wales born between 1991-2000. They identified children diagnosed with ADHD or autism by age 18 using diagnosis codes in their health records.

For each child with ADHD or autism, they matched 3 control children of the same age and sex who did not have these diagnoses.

They then looked at health records for all the children from age 16-25 to see if they had:

• Anxiety or depression
• Self-harm
• Alcohol use problems
• Drug use problems
• Emergency department visits

They compared the rates of these outcomes between the ADHD/autism groups and the control groups.

For children with ADHD, they also compared the electronic record group to a smaller group of children who had been directly assessed and diagnosed with ADHD in a previous research study.

Key Findings

Identifying ADHD and Autism

• 1.4% of children were identified as having ADHD
• 0.9% of children were identified as having autism
• These rates match well with other UK population surveys
• As expected, more boys than girls were identified with both conditions

Outcomes in Early Adulthood

Compared to matched controls, those with childhood ADHD had:

• 2.4 times higher risk of anxiety/depression
• 5.7 times higher risk of self-harm
• 4 times higher risk of alcohol problems
• 5.9 times higher risk of drug problems
• 1.4 times higher risk of emergency department visits

Those with childhood autism had:

• 2.1 times higher risk of anxiety/depression
• 2.9 times higher risk of self-harm
• 2.2 times higher risk of drug problems
• No increased risk of alcohol problems or emergency visits

These increased risks were similar for males and females and across different levels of social deprivation.

Comparison to Directly Assessed ADHD Group

The children identified through electronic records were similar to those directly assessed for ADHD in terms of their outcomes. The only difference was that those in the electronic records were diagnosed at a slightly older age on average.

What This Means

This study shows that electronic health records can be used to successfully identify large groups of children with ADHD and autism and track their outcomes over time. The increased risks found for mental health problems, substance use, and self-harm match what we would expect based on other research. This validates the method of using electronic records for this type of research.

Using electronic health records has several advantages:

• It allows researchers to study very large numbers of people with ADHD and autism
• It avoids the problem of participants dropping out over time
• It includes people who might be less likely to take part in traditional research studies

These advantages mean that results from studies using electronic records may be more representative of the whole population of people with ADHD and autism.

Limitations

There are some limitations to keep in mind:

• The study relied on diagnoses and problems being recorded in health records. Some people with ADHD or autism may not have been diagnosed or had their diagnosis recorded.

• Similarly, some mental health or substance use problems may not have been reported to healthcare services or recorded in the records.

• The follow-up period was not very long for the youngest people in the study, so some problems occurring later in adulthood may have been missed.

• The study only looked at diagnoses made in childhood (before age 18). Some people, especially females, may be diagnosed with ADHD or autism as adults.

Conclusions

• Electronic health records can be used to identify children with ADHD and autism and study their outcomes into early adulthood
• This method produces results that match what we would expect based on other research
• Using electronic records allows researchers to study very large numbers of people over time without issues of participants dropping out
• This approach could be valuable for future research on the long-term impacts of ADHD and autism and for planning health and social services