Placebo response rates in individual trials with cisapride with excellent symptom improvement. Shaded symbols are open studies. There are two observations. In both there is large variability at low sample size. Almost all of this variation is, as expected, with the smallest studies with sample sizes of 30 patients or fewer.
Larger samples are less inaccurate.
Variation in cisapride effects Figures 3 and 4 show the individual trial responses to cisapride for an excellent and a good or excellent response, respectively. Again there is considerable variation. But now the response for the open studies is considerably different from that for the double blind studies. Shaded symbols are open studies. Cisapride response rates in individual trials with cisapride with excellent symptom improvement.