Further statistics in dentistry. Part 4: Clinical trials 2.
The principles which underlie a well-designed clinical trial were introduced in a previous paper. The trial should be controlled (to ensure that the appropriate comparisons are made), randomised (to avoid allocation bias) and, preferably, blinded (to obviate assessment bias). However, taken in isolation, these concepts will not necessarily ensure that meaningful conclusions can be drawn from the study. It is essential that the sample size is large enough to enable the effects of interest to be estimated precisely, and to detect any real treatment differences.
Petrie
A
A
Biostatistics Unit, Eastman Dental Institute for Oral Health Care Sciences, University College London. a.petrie@eastman.ucl.ac.uk
Bulman
J S
JS
Osborn
J F
JF
D002986:Clinical Trials as Topic / Q000379:methods / Q000706:statistics & numerical data*; D018865:Dental Research / Q000379:methods; D006801:Humans; D018401:Sample Size