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Clinical Trials in TMD Sections
Author Bio
Introduction
The Biopsychosocial Model
Currently selected section: Designing Multicenter RCTs
Players in an RCT
Randomization
Trial Design Quality
TMD Case Definition
Endpoints and Outcome Measures
Blinding & Masking
Study Sample Size
Number and Nature of Interventions
Study Length and Follow up
Intent-to-treat Analyses and Sample Size
Compliance
Multicenter RCTs
Implementing RCTs: Practical Issues
Analysis of TMD Trials
Conclusions
Acknowledgments
Appendix A
Appendix B

 

Chapter 22: Clinical Trials in Temporomandibular: Designing Multicenter RCTs
          

Multicenter RCT Overview

Definition of a Multicenter RCT

A multicenter RCT can be defined as a formally constituted collaborative effort involving at least two non-affiliated institutions--clinical research centers, hospitals, medical or dental schools, etc-who each recruit, and enroll subjects in a clinical trial using consensually agreed upon protocols and then following up cohorts of patients with common outcome measures.

The number of multicenter RCTs has increased dramatically in the past decade, many funded by NIH and many funded in whole or in part by the biomedical industry, especially pharmaceutical manufacturers. However, there have been virtually no true multicenter RCTs conducted investigating TMD, despite the already alluded to plethora of clinical research in the field.

The major reason for conducting multicenter trials is to recruit and enroll adequate numbers of patients to allow a realistic test of experimental hypotheses. This is especially true when investigating treatments for more rarely occurring conditions; however, even with more prevalent disorders, large trials provide the most secure scientific data, all other things being equal; large trials mean many participants, which, in turn means involving many clinical centers.

Prevalence estimates are low for some TMD subtypes, of the order of 1-8% of TMD cases, for many forms of TMD involving disk disorders or degenerative conditions of the TMJ as the sole disorder. RCTs requiring hundreds of participants cannot be accomplished at a single center, and an important reason our knowledge of TMD remains limited in several spheres has been the lack of effort to mount multicenter trials that can accumulate sufficient sample sizes for experimental hypothesis testing.

Two additional related reasons for supporting multicenter trials are:

  • The opportunity afforded to investigate, with adequate sample sizes, the effect of a planned intervention on more than one target population, distinguished by ethnicity, geography, psychosocial or lifestyle levels of function, and/or socioeconomic status. For example, are all ethnic groups equally affected by the experimental treatment; do rural and urban centers yield comparable results, etc.
  • Multicenter trials afford the opportunity to investigate multiple treatments in the case where each clinical site is assured of securing a sample size large enough to evaluate one type of treatment, but unable to adequately investigate two or more treatment interventions.

 

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