The logarithmic transformation and the geometric mean in reporting experimental IgE results: what are they and when and why to use them?
- Ann Allergy Asthma Immunol, 100(6), p.625-626, 2008 .
Immunologic data, such as IgE and interleukin 4, tend to have positively skewed distributions with a long tail of larger values. This renders analyses based on normal distribution theory questionable (eg, t tests and analysis of variance)and distorts the sample mean as a measure of central tendency. These problems can be addressed through analysis of log-transformed data. Data analyzed in this fashion are summarized with the geometric mean.