Heterogeneity Statistics

This tab displays distributions across all markers for the following heterogeneity statistics: Cochran's Q, the p-value for Cochran's Q, and I2 when either of the inverse variance methods for combining p-values has been selected as the Method to Use and an Effect ID Variable has been specified.

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A set of distributions

These statistics can tell you whether the fixed or random effects model is appropriate for combining p-values for a marker. Low values of Cochran's Q and I2 and a non-significant Cochran's Q p-value indicate small amounts of heterogeneity between studies and thus a fixed effects model is likely appropriate. Otherwise, a random effects model should be used.

The Local Data Filter on the right can be used to view the distributions for a single or a subset of chromosomes at a time. Note however that this does not actually select markers for the drill-down buttons. Markers can be selected either by clicking on chromosomes in the legend below the plot or by selecting points in the plot using left-click with the mouse.