This ignores the fact that many trials do not result in an effective intervention.
This supports previous reports, that many trials do not report harms, or do so in a fragmented or suboptimal way [ 167].
The fact that many trials do not recruit their target sample sizes [ 40] may suggest acquiescence in such sample size over-estimation.
This knowledge should serve as a lesson in the current development of other agents in NSCLC, where many trials do not meet their end points because of a questionable clinical benefit in unselected populations.
Several investigations of recruitment have attempted to quantify the extent of the problem, and while estimates differ, it is clear that many trials do not meet their recruitment targets. 2 4–6 Of those that do, many achieve them only after extending the length of the trial.
As many trials do not report this information directly (Altman et al, 1995), appropriate data such as log rank test results were extracted to allow estimation of the log HR and its variance using previously reported methods (Parmar et al, 1998; Williamson et al, 2002).
Although many MDA trials did not interrupt transmission, most succeeded in considerably reducing parasite prevalence, and some showed marked reduction in incidence of cases and deaths (32 ).
Many early trials did not use prenatal steroids or surfactant, and later studies used HFOV with low mean airway pressures and therefore did not take advantage of the open-lung benefits of HFOV.
5 Additionally, a number of randomized, placebo-controlled clinical trials of vitamin D supplementation among patients with MS have reported lower numbers of gadolinium-enhancing lesions (GELs) 6 and relapses 7 or no effect of 25(OH D on any MS endpoint, 8, 9 although it must be noted that many clinical trials did not have sufficient power to detect an effect of 25(OH D on MS disease activity.
