openEBGM-package: openEBGM: EBGM Disproportionality Scores for Adverse Event...

openEBGM-packageR Documentation

openEBGM: EBGM Disproportionality Scores for Adverse Event Data Mining

Description

An implementation of DuMouchel's (1999) \Sexpr[results=rd]{tools:::Rd_expr_doi("10.1080/00031305.1999.10474456")} Bayesian data mining method for the market basket problem. Calculates Empirical Bayes Geometric Mean (EBGM) and posterior quantile scores using the Gamma-Poisson Shrinker (GPS) model to find unusually large cell counts in large, sparse contingency tables. Can be used to find unusually high reporting rates of adverse events associated with products. In general, can be used to mine any database where the co-occurrence of two variables or items is of interest. Also calculates relative and proportional reporting ratios. Builds on the work of the 'PhViD' package, from which much of the code is derived. Some of the added features include stratification to adjust for confounding variables and data squashing to improve computational efficiency. Includes an implementation of the EM algorithm for hyperparameter estimation loosely derived from the 'mederrRank' package.

Data preparation & squashing functions

The data preparation function, processRaw, converts raw data into actual and expected counts for product/event pairs. processRaw also adds the relative reporting ratio (RR) and proportional reporting ratio (PRR). The data squashing function, squashData, implements the simple version of data squashing described in DuMouchel et al. (2001). Data squashing can be used to reduce computational burden.

Negative log-likelihood functions

The negative log-likelihood functions (negLL, negLLsquash, negLLzero, and negLLzeroSquash) provide the means of calculating the negative log-likelihoods as mentioned in the DuMouchel papers. DuMouchel uses the likelihood function, based on the marginal distributions of the counts, to estimate the hyperparameters of the prior distribution.

Hyperparameter estimation functions

The hyperparameter estimation functions (exploreHypers and autoHyper) use gradient-based approaches to estimate the hyperparameters, \theta, of the prior distribution (gamma mixture) using the negative log-likelihood functions from the marginal distributions of the counts (negative binomial). \theta is a vector containing five parameters (\alpha_1, \beta_1, \alpha_2, \beta_2, and P). hyperEM estimates \theta using a version of the EM algorithm.

Posterior distribution functions

The posterior distribution functions calculate the mixture fraction (Qn), geometric mean (ebgm), and quantiles (quantBisect) of the posterior distribution. Alternatively, ebScores can be used to create an object of class openEBGM that contains the EBGM and quantiles scores. Appropriate methods exist for the generic functions print, summary, and plot for openEBGM objects.

Author(s)

Maintainer: John Ihrie John.Ihrie@fda.hhs.gov

Authors:

Other contributors:

  • Ismaïl Ahmed (author of 'PhViD' package (derived code)) [contributor]

  • Antoine Poncet (author of 'PhViD') [contributor]

  • Sergio Venturini (author of 'mederrRank' package (derived code)) [contributor]

  • Jessica Myers (author of 'mederrRank') [contributor]

References

Ahmed I, Poncet A (2016). PhViD: an R package for PharmacoVigilance signal Detection. R package version 1.0.8.

Venturini S, Myers J (2015). mederrRank: Bayesian Methods for Identifying the Most Harmful Medication Errors. R package version 0.0.8.

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.

DuMouchel W, Pregibon D (2001). "Empirical Bayes Screening for Multi-item Associations." In Proceedings of the Seventh ACM SIGKDD International Conference on Knowledge Discovery and Data Mining, KDD '01, pp. 67-76. ACM, New York, NY, USA. ISBN 1-58113-391-X.

Evans SJW, Waller P, Davis S (2001). "Use of Proportional Reporting Ratios (PRRs) for Signal Generation from Spontaneous Adverse Drug Reaction Reports." Pharmacoepidemiology and Drug Safety, 10(6), 483-486.

FDA (2017). "CFSAN Adverse Event Reporting System (CAERS)." URL https://www.fda.gov/food/compliance-enforcement-food/cfsan-adverse-event-reporting-system-caers.

See Also

Useful links:


openEBGM documentation built on Sept. 15, 2023, 1:08 a.m.