An n-of-1 trial service in clinical practice: testing the effectiveness of stimulants for attention-deficit/hyperactivity disorder.
OBJECTIVE
We sought to describe the clinical use of n-of-1 trials for attention-deficit/hyperactivity disorder in publicly and privately funded family and specialized pediatric practice in Australia.


METHODS
We used a within-patient randomized, double-blind, crossover comparison of stimulant (dexamphetamine or methylphenidate) versus placebo or alternative stimulant using 3 pairs of treatment periods. Trials were conducted from a central location using mail and telephone communication, with local supervision by the patients' clinicians.


METHODS
Our study population included children with clinically diagnosed attention-deficit/hyperactivity disorder who were aged 5 to 16 years and previously stabilized on an optimal dose of stimulant. They were selected because treatment effectiveness was uncertain.


METHODS
Our measures included number of patients recruited, number of doctors who used the service, geographic spread, completion rates, response rate, and post-n-of-1 trial decisions.


RESULTS
Forty-five doctors across Australia requested 108 n-of-1 trials, of which 86 were completed. In 69 drug-versus-placebo comparisons, 29 children responded better to stimulant than placebo. Immediately posttrial, 19 of 25 drug-versus-placebo responders stayed on the same stimulant, and 13 of 24 nonresponders ceased or switched stimulants. In 40 of 63 for which data were available, posttrial management was consistent with the trial results. For all types of n-of-1 trials, management changed for 28 of 64 children for whom information was available.


CONCLUSIONS
Attention-deficit/hyperactivity disorder n-of-1 trials can be implemented successfully by mail and telephone communication. This type of trial can be valuable in clarifying treatment effect when it is uncertain, and in this series, they had a noticeable impact on short-term management.
Nikles
C Jane
CJ
The University of Queensland, Herston, Queensland 4006, Australia. uqjnikle@uq.edu.au
Mitchell
Geoffrey K
GK
Del Mar
Chris B
CB
Clavarino
Alexandra
A
McNairn
Norma
N
D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy*; D000697:Central Nervous System Stimulants / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D002986:Clinical Trials as Topic / Q000379:methods; D018592:Cross-Over Studies; D003913:Dextroamphetamine / Q000627:therapeutic use*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008774:Methylphenidate / Q000627:therapeutic use*
D000697:Central Nervous System Stimulants; D008774:Methylphenidate; D003913:Dextroamphetamine