ACAT (Aggregated Cauchy Association Test)

ACAT [R package] or Cauchy combination test is a generic method that utilizes the Cauchy distribution to effectively combine correlated p-values. It first transforms the individual p-values to Cauchy variables, then takes the (weighted) summation of them as the test statistic.

Key features

  • The overall p-value of ACAT can be accurately approximated by a Cauchy distribution without the need to account for the correlations among individual p-values.

  • Super fast computation

  • Powerful when signals are sparse

Reference

Liu, Y. and Xie, J.(2020). Cauchy combination test: a powerful test with analytic p-value calculation under arbitrary dependency structures. Journal of the American Statistical Association. 115(529), 393-402.

Liu, Y., Chen, S., Li, Z., Morrison, A.C., Boerwinkle, E., and Lin, X. (2019). ACAT: a fast and powerful p-value combination method for rare-variant analysis in sequencing studies. The American Journal of Human Genetics. 104(3), 410-421.