University of Michigan
Department of Pediatrics
Evidence-Based Pediatrics Web Site

Question

• Are single patient, double-blind, placebo controlled, methylphenidate trials (MPT) useful and practical in a primary care setting?

Clinical Bottom Lines

1. ADHD is a common (3-10%) diagnosis amongst school age children, however, there is a wide range in how clinicians and families arrive at treatment decisions.
2. Single patient, double-blind, placebo controlled, methylphenidate trials provide an objective measure of methylphenidate efficacy in individual patients.¹
3. All parents who completed the trial found results to be helpful, and most used results as sole factor in deciding whether to continue methylphenidate.
4. Compliance with single patient trials was high despite socioeconomic restraints and comorbidity that can accompany children with ADHD.

Summary of Key Evidence

1. 50 children ages 4-14 enrolled in a 3 week double-blind, placebo controlled, methylphenidate trials, with one week each of placebo, 0.3mg/kg and 0.5mg/kg given po q8am and qnoon.¹
2. Study was performed at a large tertiary children's hospital in Canada.
3. Inclusion criteria: age 4-14, DSM IV diagnosis of ADHD and willing to participate in study.
4. Exclusion criteria: previous diagnosis of PDD, developmental delay, or unwilling to follow study guideline.
5. Outcome measured at baseline and at the end of each week by 1 parent and 2 teachers, Connor's scales and objective comments.
6. Parents offered continuation of methylphenidate at end of trial if >1 SD decrease in hyperactivity sub-scale on any one Connor's scale and positive comments.
7. Family interview at 14-21 months to assess patient's subsequent treatment and ADHD symptoms.
8. Of parents available at follow-up, 68% used MPT as sole determinant of whether to continue methylphenidate after MPT.  All found MPT useful.
9. At time of follow-up 20/31 that showed response to methylphenidate during MPT were still on methylphenidate.  None of the 6 with a negative MPT (no response to methylphenidate) where on methylphenidate at time of follow-up.

Additional Comments

• Study population included only those willing to follow guidelines of study - skews results given, this represents a motivated subset of families, but may better represent those who would participate in an office-based MPT.
• Study at tertiary referral center - results may not be reproducible in primary care setting.
• Practical obstacles to office based MPT include time constraint, family motivation and cooperation of parents, teachers and pharmacy.
• Patients at long term follow-up not compared to a control group.
• Unable to use study results to evaluate MPT as a prognostic indicator indicator of methylphenidate use at long term follow-up because patients treated differently based on MPT results.

Citation

1. Kent MA, Camfield CS, Camfield PR.  Double-blind methylphenidate trials: Practical, useful, and highly endorsed by families.  Archives of Pediatrics & Adolescent Medicine, 1999; 153(12):1292-1296.
2. Clinical Practice Guideline: Diagnosis and Evaluation of the Child With Attention Deficit/Hyperactivity Disorder.  Pediatrics, 2000; 105:1158-1170.
3. Miller KJ.  Attention deficit/hyperactivity disorders.  Pediatrics In Review, 1998; 19(11):373-384.

CAT Author: Todd Koffler, MD

CAT Appraisers: John G. Frohna, MD

Date appraised: June 29, 2000