Use of double-blind placebo-controlled N-of-1 trials among stimulant-treated youths in The Netherlands: a descriptive study.
OBJECTIVE
An N-of-1 trial is a double-blind placebo-controlled randomized trial to objectively and systematically evaluate the individual's response. This approach seems extraordinarily suitable for assessing the efficacy of stimulants in the treatment of attention deficit hyperactivity disorder (ADHD). The aim is to examine the use of N-of-1 trials among youths in the Netherlands, the protocols used, and the continuation of stimulant treatment thereafter.


METHODS
Physicians requesting N-of-1 trials with stimulants were interviewed about their rationale and protocol. Prevalence and continuation were investigated by extracting N-of-1 trials among youths <20 years of age from a large pharmacy dispensing database for 2000-2004.


RESULTS
The main purpose of N-of-1 trials mentioned by physicians was the assessing of individuals' response and dose-finding. Trial length, dosing schedule and efficacy assessment differed per physician. Trials consisted of a maximum of two treatment periods per dose. The annual percentage of youths starting stimulant treatment with an N-of-1 trial fluctuated between 0.6% (3/462) and 3.3% (10/301). No statistical significant difference could be detected between the continuation of stimulant treatment with or without an N-of-1 trial (p = 0.71).


CONCLUSIONS
N-of-1 trials with stimulants are infrequently and not optimally used in the Netherlands. The results of N-of-1 protocols described by physicians are of questionable value, due to the small number of treatment periods per dose. More uniformity in the protocols would make it easier to encompass the N-of-1 methodology in physicians' daily practice.
Faber
Adrianne
A
Department of Social Pharmacy, Pharmacoepidemiology and Pharmacotherapy, Groningen University Centre for Drug Exploration (GUIDE), Antonius Deusinglaan 2, 9713 AV, Groningen, The Netherlands. adrianne.faber@chello.nl
Keizer
Ron J
RJ
van den Berg
Paul B
PB
de Jong-van den Berg
Lolkje T W
LT
Tobi
Hilde
H
D000293:Adolescent; D000328:Adult; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy; D000697:Central Nervous System Stimulants / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D016208:Databases, Factual; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008774:Methylphenidate / Q000627:therapeutic use; D009426:Netherlands / Q000453:epidemiology; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data / Q000639:trends; D016032:Randomized Controlled Trials as Topic / Q000379:methods*; D011795:Surveys and Questionnaires
D000697:Central Nervous System Stimulants; D008774:Methylphenidate