Using the method described in Section 2.4.2, an algorithm adapted from Storey and Tibshirani (2003) was used to determine the false discovery rate based on an estimate of the probability of a true null hypothesis. This estimate is based on the distribution of p-values of the entire set of regression calculations. This procedure, when applied to the p-values of the genotypic parameters from the 6288 regression calculations provided a conservative estimate of the probability of a true null hypothesis at .63. This is illustrated in figure 3. To control the false discovery rate at 5%, the p-value threshold was set at p < 0.009, which includes 24% of the values tested. Correspondingly, as described in Section 2.4.2, using the proportion threshold to deal with median p-values for the condensed age ranges, 24% of the median p-values are less than 0.0136. To control the false discovery rate at 1%, the p-values threshold was set at p < 6.2 × 10−5, which includes 8% of the genotypic parameters. Correspondingly, 8% of the median p-values are less than .0014.
