Health Spring Meeting May 2008 Session # 42: Dental Insurance What's New, What's Important

Transcription

1 Health Spring Meeting May 2008 Session # 42: Dental Insurance What's New, What's Important Floyd Ray Martin, FSA, MAAA Thomas A. McInteer, FSA, MAAA Jonathan P. Polon, FSA

2 Dental Insurance Fraud Detection With Predictive Modeling SOA Spring Health Meeting May 29, 2008 Jonathan Polon FSA Agenda Intro to Predictive Modeling Supervised vs Unsupervised Learning Modeling Procedures Dental Insurance Fraud Detection Examples of Atypical Dentists 1

3 Introduction to Predictive Modeling A Part of Everyday Life Have you used a predictive model today? Mail sorting Credit card processing Credit scores Weather forecasting Grocery shopping 2

4 What is Predictive Modeling Harnesses power of modern computers to find hidden patterns in data Used extensively in industry Many possible uses in insurance: Claim management Pricing Reserving Fraud detection Predictive Modeling Tools Some common techniques Generalized linear models Neural networks Genetic algorithms Random forests Stochastic gradient boosted trees Support vector machines 3

5 Supervised Vs Unsupervised Learning Supervised Learning In the training dataset, there is a known outcome associated with each record Learning objective: build a model that can accurately estimate the outcomes from the predictor variables for each record Eg, Sports Betting: predict winners based on observations from past games Commonly referred to as predictive modeling 4

6 Unsupervised Learning In the training dataset, there is not an outcome associated with any record Learning objective: self-organization or clustering; finding structure in the data. Eg, Grocery Stores: define types of shoppers and their preferences Modeling Dental Procedures 5

7 Why Model Procedures? There s more to diagnosis than category within categories, severity varies similarities can exist between procedures of different categories how do we extract more information? Scoring Procedures Create a series of metrics for each procedure some relative values from 0 10 Some absolute values for example: - unbundling - specialized - major problem - emergency allows every procedure to be compared to every other procedure 6

8 Scoring Procedures - Example Category Caries, trauma, pain control Restorative Pulpotomy, molars, emergency Endodontics Root canals, 3 canals, calcified Endodontics Specialized Major work Emergency No Yes No Dental Fraud Detection Using Unsupervised Learning 7

9 Research Project 200,000 dental claim records from 2004 General practitioners in Ontario Applied modern pattern detection techniques to identify dentists with atypical claims histories Research paper: Dental Insurance Claims: Identification of Atypical Claims Activity Traditional Tools Rule-based Strong at identifying claims that match known types of fraudulent activity Limited to identifying what is known Typically analyze at the level of a single claim, in isolation 8

10 Pattern Detection Tools Analyze millions of claims to reveal patterns Technology learns what is normal and what is atypical not limited by what we already know Categorize each claim, reveals dentists with a high percentage of atypical claims Immediately highlights new questionable behaviors Finds new large dollar schemes Also identifies frequent repetition of small dollar abuses Methodology 3 Perspectives 1. By Claim e.g. Joe Green s semi-annual check-up 2. By Tooth e.g. all work done in 2004 on Joe s bicuspid by Dr. Brown 3. By General Work e.g. all general work (exams, fluoride, radiographs, scaling and polishing) done on Joe in 2004 by Dr. Brown 9

11 Methodology 2 Techniques 1. Principal components analysis 2. Clustering Methodology Summary Claim by claim Tooth by tooth General work PCA Cluster 10

12 Principal Components Analysis Allows reduction of multi-dimensional data to lower dimensions while maximizing amount of information preserved Reducing to 2 dimensions allows data points to be plotted on a chart Powerful approach for identifying outliers PCA: Simple Example 6 PCA: Sam ple Data 4 2 Y-Axis X-Axis Lots of variance between points around both axes 11

13 PCA: Simple Example 6 PCA: Rotate Axes 45 o 4 2 Y-Axis X-Axis Create new axes, X and Y : rotate original axes 45 o PCA: Simple Example 6 PCA: Rotated Axes 4 2 Y'-Axis X'-Axis In the new axes, very little variance around Y Y contains little information 12

14 PCA: Simple Example PCA: Reduce to 1 Dimension Original Revised Y'-Axis X'-Axis Can set all Y values to 0 ie, ignore Y axis Result: reduce to 1 dimension with little loss of info PCA: Identifying Atypical Dentists 13

15 PCA: Identifying Atypical Dentists 1. Begin at the individual transaction level 2. Determine the average transaction for each dentist 3. Graph quickly isolates dentists that are outliers PCA: Identifying Atypical Dentists Dentist Average 90 th percentile 14

16 PCA: Summary 1. Visualization allows for easy and intuitive identification of dentists that are atypical 2. Manual investigation required to understand why a dentist or claim is atypical Clustering Techniques Categorization tools Organize claims into several groups of similar claims Applicable for profiling dentists by looking at the percentage of claims in each cluster We apply two different clustering techniques: K-Means and Expectation-Maximization 15

17 Clustering Example Clustering Example Clustering Example Clustering Example 16

18 Example: Clusters found by Claim 1. Major dental problems 2. Moderate dental problems 3. Age > 28, minor work performed 4. Work includes unbundled procedures 5. Minor work and expensive technologies 6. Age < 28, minor work performed Clusters: Identifying Atypical Dentists 1. Begin at the individual claim level 2. Calculate the proportion of claims in each cluster in total, and for each dentist 3. Isolate dentists with large deviations from average 17

19 Clusters: Identifying Atypical Dentists 100% Proportion of General Work by Cluster K-Means Clustering 80% % Claims X 60% 40% 20% 0% Average 19% 2% 6% 20% 6% 9% 21% 17% Dent A 0% 0% 0% 0% 0% 49% 0% 51% Clustering Techniques: Summary 1. Clustering provides an easy to understand method to profile dentists 2. Unlike PCA, clustering tells why a given dentist is considered atypical 3. Effectively identifies atypical activity at the dentist level 18

20 Pilot Project Results PCA identified 68 dentists that are atypical Clusters identified 182 dentists that are atypical 36 dentists are identified as atypical by both PCA and Clusters In total, 214 of 1,644 dentists are identified as atypical (13%) Billings by atypical dentists were $2.5 MM out of $16.1 MM billed by all dentists (15%) Examples Of Atypical Dentists 19

21 Dentist A 100% Proportion of General Work by Cluster K-Means Clustering 80% % Claims X 60% 40% 20% 0% Average 19% 2% 6% 20% 6% 9% 21% 17% Dent A 0% 0% 0% 0% 0% 49% 0% 51% Analysis: Dentist A is far beyond norms in clusters 6 and 8; both indicate high charges in general dentistry What we discovered: Each of Dentist A s patients is being billed for at least 30 minutes of polishing and 45 minutes of scaling Dentist B 100% Proportion of Teeth by Cluster K-Means Clustering 80% % Claims X 60% 40% 20% 0% Average 22% 9% 5% 13% 19% 25% 8% Dent B 5% 20% 21% 0% 0% 0% 54% Analysis : Dentist B is far beyond norms in cluster 7 (age > 19, major work) What we discovered: Frequent extractions and anesthesia Dentist B looks like an oral surgeon, but is a general practitioner 20

22 Dentist C 100% Proportion of General Work by Cluster EM Clustering 80% % Claims X 60% 40% 20% 0% 1 2 Average 23% 77% Dent C 66% 34% Analysis: Very high proportion in Cluster 1, suggesting many high-ticket visits What we discovered: First, Dentist C performs an inordinate amount of scaling (average of 1 hour p.p.). Second, Dentist C has emergency examinations with atypically high frequency Dentist M Analysis: Dentist M has a disproportionate amount of work beyond the 90 th percentile of work by all dentists on all teeth What we discovered: Dentist M appears to utilize lab work very heavily 21

23 More Atypical Dentists Frequent use of panoramic x-rays Frequent use of nitrous oxide including with procedures rarely associated with anesthesia Large number of extractions, often using multiple types of sedation Very high proportion of claims for crowns and endodontic work Individual instruction on oral hygiene provided with very atypical frequency Dental Fraud Summary Pattern detection: Highly effective in identifying dentists with claim portfolios significantly different from the norm Enables experts to quickly identify and focus on those dentists with atypical claims activity 22

24 Questions? 23