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Use of double-blind placebo-controlled N-of-1 trials among stimulant-treated youths in The Netherlands: a descriptive study

European Journal of Clinical Pharmacology volume 63, pages 57–63 (2007)Cite this article

Abstract

Objectives

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.

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Affiliations

  1. Department of Social Pharmacy, Pharmacoepidemiology and Pharmacotherapy, Groningen University Centre for Drug Exploration (GUIDE), Antonius Deusinglaan 2, 9713 AV, Groningen, The Netherlands

    Adrianne Faber, Ron J. Keizer, Paul B. van den Berg, Lolkje T. W. de Jong-van den Berg & Hilde Tobi

  2. SIR Institute for Pharmacy Practice and Policy, Theda Mansholtstraat 5b, 2331 JE, Leiden, The Netherlands

    Adrianne Faber

  3. Social Sciences, Research Methodology Group, Wageningen University Research, Bode 175, P.O. Box 8130, 6700 EW, Wageningen, The Netherlands

    Hilde Tobi

  4. SIR Institute for Pharmacy Practice and Policy, Theda Mansholtstraat 5b, 2331 JE, Leiden, The Netherlands

    Adrianne Faber

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  1. Adrianne Faber
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  2. Ron J. Keizer
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  3. Paul B. van den Berg
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  4. Lolkje T. W. de Jong-van den Berg
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  5. Hilde Tobi
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Correspondence to Adrianne Faber.

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Faber, A., Keizer, R.J., van den Berg, P.B. et al. Use of double-blind placebo-controlled N-of-1 trials among stimulant-treated youths in The Netherlands: a descriptive study. Eur J Clin Pharmacol 63, 57–63 (2007). https://doi.org/10.1007/s00228-006-0219-7

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  • DOI: https://doi.org/10.1007/s00228-006-0219-7

Keywords

  • N-of-1 trial
  • Stimulant
  • Methylphenidate
  • Attention deficit hyperactivity disorder