Journal of Dental Research, Vol 74, 1453-1458, Copyright © 1995 by International & American Associations for Dental Research Online Journals
Definitive vs. exploratory periodontal trials: a survey of published studies
P. P. Hujoel
Department of Dental Public Health Sciences, School of Dentistry, University of Washington, Seattle 98195, USA.
Definitive and exploratory randomized controlled trials (RCTs) have
different goals as well as different design and analysis characteristics.
The goal of definitive studies is to provide unequivocal evidence of a
treatment's tangible benefit to the patient; a pre-trial-specified
hypothesis is tested by use of a pre-trial-specified method. The goal of
exploratory studies is to elucidate biological treatment mechanisms, to
identify promising treatments, and to generate hypotheses for definitive
studies; multiple hypotheses are evaluated to extract as much information
from the data as possible. The purposes of this study were: (1) to survey
selected design and analysis characteristics of randomized controlled
periodontal trials published between 1988 and 1992 (n = 86), and (2) to
classify trials as exploratory or definitive studies. The peridontal RCTs
surveyed were typical of exploratory studies whose primary goal was to
elucidate biological treatment mechanisms. Trial reports indicated the
testing of multiple hypotheses (> or = 6 hypothesis tests in 70 of the
86 trials) on a variety of biological markers (86 out of 86 trials). The
sample size (< or = 30 subjects in 67 out of 86 trials), duration (<
or = 6 months in 65 out of 86 trials), and design and analysis
characteristics (e.g., an absence of masking in 57 out of 86 trials) were
also typical of exploratory studies which strive to obtain quick answers
(short duration) at a low cost (small sample size; accept bias for
increased efficiency and a lower cost). No definitive trials were
identified.(ABSTRACT TRUNCATED AT 250 WORDS)
