Evidence based management of attention deficit hyperactivity disorder. (Evidence based paediatrics).

This is the last in a series of five articles

Summary points

Some 7% of children of school age have attention deficit hyperactivity disorder, and boys are affected three times as often as girls

Between 18% and 35% of affected children have an additional psychiatric disorder

ADHD-specific ratings scales are useful in the diagnostic evaluation

Stimulants, and perhaps tricyclic antidepressants, are effective treatments for attention deficit hyperactivity disorder in children

Symptoms diminish over time, but in up to half of affected children the disorder is still present in adolescence or young adulthood

THE CASE Your first patient of the morning is brought in by his parents for evaluation of school problems. He has always been described as "on the go." When he was 4 years old, a preschool teacher expressed concern that his activity level at times limited play with other children. Now, in the middle of second grade, he is underachieving and not keeping up with either reading or mathematics. His teacher reports that he fidgets constantly and cannot keep his hands off other children. Friendships are limited and not sustained. His teacher suggested that his paediatrician should be asked whether he has attention deficit hyperactivity disorder.

Background

Attention deficit hyperactivity disorder (ADHD) is among the most common neurodevelopmental disorders in children. (1) Its hallmarks are hyperactivity, impulsiveness, and inattention beyond the norm for a child's age (box). (2)

The disorder is frequently diagnosed in children with behavioural problems or in those who underachieve at school. (3) Although the diagnosis is reliable if made by a standardised approach, concerns about the validity of the disorder often arise. (4) At present there is no biological marker that clearly identifies affected children. Furthermore, it is unclear whether the disorder is unique or merely one end of the continuum of age appropriate behaviour. (5 6)

You wonder how frequently academic difficulties or disruptive behaviours in a child are due to attention deficit disorder or to another psychiatric disorder; what tests will be helpful to diagnose the disorder; what treatments are effective; and what is the prognosis. For your patient, these questions need to be answered before you can decide on the best course of action.

Database queries

You wish to use an evidence based approach, so you frame your questions to maximise the yield from searching, and you look first for high quality systematic reviews and evidence based guidelines to answer your questions. You specify in each case the population, the event or exposure, the intervention, and the outcome, and identify the question type--whether it seeks evidence of a prevalence or risk in a baseline population, a prognosis, or the value of therapy.

(1) In children of school age (population), what is the likelihood of ADHD (outcome)? [baseline risk]

(2) In children of school age (population) with ADHD (exposure), what is the likelihood of additional psychiatric disorders (outcome)? [baseline risk]

(3) In children of school age (population) suspected of having ADHD (exposure), what is the value of behavioural rating scales and other tests (intervention) in the diagnosis (outcome)? [diagnostic test]

(4) In …