Analysis of the Effect of Multiple Testing in Assessing Tobacco Product Differences

During the last two decades, an increase of tobacco product reporting requirements from regulators was observed, such as Europe, Canada or USA.

However, the capacity to compare and discriminate accurately two products is impacted by the number of constituents used for the comparison. Indeed, performing a large number of simultaneous independent hypothesis tests increases the probability of rejection of the null hypothesis when it should not be rejected. This leads to virtually guarantee the presence of type I errors among the findings. Correction methods have been developed to overcome this issue like the Bonferroni or Benjamini & Hochberg ones. The performance of these methods was assessed by comparing identical tobacco products with different sizes of data sets. Results showed that multiple comparisons lead to erroneous conclusions if the risk of type I error is not corrected. Unfortunately, reducing the type I error impacts the statistical power of the tests. Consequently, strategies for dealing with multiplicity of data should provide a reasonable balance between testing requirement and statistical power of differentiation. Multiple testing for product comparison is less of a problem if studies restrict to the most relevant parameters for comparison.