To further assess deviation from the linearity assumption, a trend test for BP as a continuous variable was performed for the different headache categories, in which, the trend test for BP as a categorical variable had shown significance.
χ tests were used to assess deviation from Hardy Weinberg equilibrium.
Treatment effects were evaluated by assessing deviation from the grand mean.
The chi-square test was used to assess deviation from Hardy-Weinberg equilibrium (HWE).
Tajima's D statistic was also calculated to assess deviation from the neutral mutation model[ 41].
A chi-square test was performed to assess deviation from the expected uniform distribution.
The Pearson goodness of fit χ test was used to assess deviation from Hardy-Weinberg equilibrium (HWE).
Fisher's exact test was used to assess deviation from HWE in the control group according to genotypes.
For categorical variables, chi-square tests were used to assess overall significance, and its adjusted standardized residuals to assess deviation from chance for each type of center.
The intra-assay co-efficient of variance was calculated by the assessing deviation in Ct values of a selected plasmid concentration.
