Problems with Double Blind in Medicine

Yngvar Reichelt¹, Karl L. Reichelt²

¹Department of Mathematics, University of Oslo, Oslo, Norway.
²Lab 1, No 1337, Sandvika, Norway and Kleve 4541 m, University of Oslo, Oslo, Norway.

DOI: 10.4236/ojpsych.2015.52024                

Abstract

Double blind tests of drugs and procedures depend on obtaining two equal and randomly assigned groups to be compared. With a diagnosis based only on symptoms, but with different etiologies, this is not very likely. We here show the probability of obtaining two equal groups with one diagnosis but three etiologies. The mathematical name for such a problem is multivariate hypergeometric distribution. We find that increasing the group size decreases the probability.

Keywords

Diagnosis, Difference, Etiologies, Distribution, Groups

Conflicts of Interest

The authors declare no conflicts of interest.

References

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