Multicriteria decision frontiers for prescription anomaly detection over time

J Appl Stat. 2021 Jul 31;49(14):3638-3658. doi: 10.1080/02664763.2021.1959528. eCollection 2022.

Abstract

Health care prescription fraud and abuse result in major financial losses and adverse health effects. The growing budget deficits of health insurance programs and recent opioid drug abuse crisis in the United States have accelerated the use of analytical methods. Unsupervised methods such as clustering and anomaly detection could help the health care auditors to evaluate the billing patterns when embedded into rule-based frameworks. These decision models can aid policymakers in detecting potential suspicious activities. This manuscript proposes an unsupervised temporal learning-based decision frontier model using the real world Medicare Part D prescription data collected over 5 years. First, temporal probabilistic hidden groups of drugs are retrieved using a structural topic model with covariates. Next, we construct combined concentration curves and Gini measures considering the weighted impact of temporal observations for prescription patterns, in addition to the Gini values for the cost. The novel decision frontier utilizes this output and enables health care practitioners to assess the trade-offs among different criteria and to identify audit leads.

Keywords: Medicare Part D; Multivariate anomaly detection; decision models; health care fraud; prescription patterns; topic model.

Grants and funding

T.E. acknowledges the support of the Texas State University through Faculty Development Leave and Presidential Research Leave Award and through Heath Scholar Showcase award from Translational Health Research Center. This work was partially supported by the National Science Foundation under grant DMS-1638521 to the Statistical and Applied Mathematical Sciences Institute.