GPS: Gamma Poisson Shrinker (GPS)

In bips-hb/pvm: PharmacoVigilance Methods

Gamma Poisson Shrinker (GPS)

Description

Applies the Gamma Poisson Shrinker (GPS) introduced by DuMouchel (1999) to a collection of 2 x 2 tables of the form

	event	not event
drug	a	c
not drug	b	d

Usage

GPS(
  a,
  b,
  c,
  d,
  E = ((a + b) * (a + c))/(a + b + c + d),
  prior = fitPriorParametersGPS(a, b, c, d),
  alpha = NULL
)

Arguments

a	A vector with the counts of the upper left corner of the tables
b	A vector with the counts of the lower left corner of the tables
c	A vector with the counts of the upper right corner of the tables
d	A vector with the counts of the lower right corner of the tables
E	Vector with the expected values when there are no associations. By default set to the values used by DuMouchel (1999), i.e., ((a + b)*(a + c)) / (a + b + c + d).
prior	List that contains the prior parameters. If not specified, automatically fitted to the data, see fitPriorParametersGPS().
alpha	Value between (0,1). If set, the lower endpoint the confidence (or credible) interval is returned. (Default = NULL)

Value

a vector with the GPS estimates

References

DuMouchel, W. (1999). Bayesian Data Mining in Large Frequency Tables, with an Application to the FDA Spontaneous Reporting System. The American Statistician, 53(3), 177–190. https://doi.org/10.1080/00031305.1999.10474456

        DuMouchel, W., & Pregibon, D. (2001). Empirical bayes screening
        for multi-item associations. Proceedings of the Seventh ACM
        SIGKDD International Conference on Knowledge Discovery and
        Data Mining - KDD ’01, (October), 67–76.
        http://doi.org/10.1145/502512.502526

See Also

fitPriorParametersGPS()

bips-hb/pvm documentation built on Feb. 13, 2025, 3:32 a.m.