PREDICTIVE TEST FOR WHETHER A PATIENT WILL BENEFIT FROM PHARMACOGENOMICS TESTING
20230089464 · 2023-03-23
Inventors
Cpc classification
G16H20/10
PHYSICS
International classification
G16H20/10
PHYSICS
G16B20/00
PHYSICS
Abstract
Pharmacogenomic (PGx) testing provides valuable insight into patient-specific mechanisms for drug response. Limitations on the throughput of PGx testing and associated costs make it currently infeasible to test every individual, particularly in large medical enterprises such as the VA or medical centers servicing large numbers of patients simultaneously. To overcome this, a method and system is described that predicts whether a patient is likely to benefit from PGx testing. Our method permits a healthcare provider to prioritize patients for PGx testing based on which patients are identified as being most likely to benefit from the testing, and can avoid PGx testing for those patients that are likely to obtain little or no benefit from the testing, thereby saving healthcare costs.
Claims
1. A computer-implemented method for determining whether to perform a pharmacogenomics test on a patient, comprising: obtaining an input data set comprising at least one of data indicative of a disease status of the patient or data indicative of currently prescribed medications for the patient; implementing in the computer a Bayesian network representable as a tripartite graph having links between three partitions: (1) a disease status partition having elements representing one or more independent diseases of the patient; (2) a medications partition having elements representing medications associated with the elements of the disease status partition or with the currently prescribed medications for the patient; and (3) a genetics partition having elements representing particular genetic variations which have a pharmacogenomics relationship with the elements in the medications partition; wherein weights of links between the disease status partition and the medications partition are based on an analysis of a corpus of patient data comprising prescribed medications and disease diagnoses, and wherein weights of links between the medications partition and the genetics partition have binary values that depend on whether a pharmacogenomics relationship has been established between the elements of the medications partition and the elements of the genetics partition; generating from the Bayesian network a probability of the patient being prescribed a particular medication having a pharmacogenomics relationship with one of the genetic variations in the genetics partition, P(M), based on the input data; and predicting whether the patient will likely benefit from a pharmacogenomics test based on the generated probability P(M).
2. The method of claim 1, wherein the probability P(M) is generated in accordance with equation (1).
3. The method of claim 1, wherein the input data set comprises a set of ICD-10 codes or the equivalent representing diagnoses of independent diseases assigned to the patient.
4. The method of claim 1 wherein predicting whether the patient will likely benefit from the pharmacogenetics test comprises comparing on the probability P(M) to a threshold that is less than or equal to 0.01.
5. The method of claim 1, further comprising generating by the computer a prediction of the risk of the patient developing a disease in a given time frame in the future.
6. The method of claim 5, further comprising predicting medications for the predicted future disease, and generating with the Bayesian network a prediction of the probability that the patient will be prescribed a medication with a pharmacogenomics relationship in the future.
7. The method of claim 6, further comprising assigning a weight to the likelihood of the patient having an actionable genetic variant based on the prevalence of the genetic variant in the general population, and using the weight in the Bayesian network to generate the prediction of the probability that the patient will be prescribed a medication with a pharmacogenomics relationship in the future.
8. An improved computer configured to determine whether to conduct pharmacogenetics testing on a patient, comprising: a memory storing an input data set comprising at least one of data indicative of disease status of the patient, or data indicative of currently prescribed medications for the patient; a processing system configured to implement a Bayesian network representable as a tripartite graph having three partitions: (1) a disease status partition having elements representing one or more independent diseases of the patient; (2) a medications partition having elements representing medications associated with the elements of the disease status partition or with the currently prescribed medications for the patient; and (3) a genetics partition having elements representing particular genetic variations which have a pharmacogenomics relationship with the elements in the medications partition; wherein weights of links between the disease status partition and the medications partition are based on an analysis of a corpus of patient data comprising prescribed medications and disease diagnoses and wherein weights of links between the medications partition and the genetics partition have binary values that depend on whether a pharmacogenomics relationship has been established between the elements of the medications partition and the elements of the genetics partition; executable instructions for the processing unit to generate from the Bayesian network a probability of the patient being prescribed a particular medication having a pharmacogenomics relationship with one of the genetic variations in the genetics partition, P(M), based on the input data; and predicting whether the patient will likely benefit from a pharmacogenomics test based on the generated probability P(M).
9. The apparatus of claim 8, wherein the executable instructions calculate the probability P(M) in accordance with Equation (1).
10. The apparatus of claim 8, wherein the input data set comprises a set of ICD-10 codes or the equivalent representing diagnoses of independent diseases assigned to the patient.
11. The apparatus of claim 8, wherein the instructions further include a threshold for recommending a pharmacogenetics test based on the probability P(M) and wherein the threshold is less than or equal to 0.01.
12. The apparatus of claim 8, further comprising instructions for generating a prediction of the risk of the patient developing a disease in a given time frame in the future.
13. The apparatus of claim 12, wherein the instructions include instructions for predicting medications for the predicted future disease, and generating with the Bayesian network a prediction of the probability that the patient will be prescribed a medication with a pharmacogenomics relationship in the future.
14. The apparatus of claim 12, wherein a weight is assigned to the likelihood of the patient having an actionable genetic variant based on the prevalence of the genetic variant in the general population, and using the weight in the Bayesian network to generate the prediction of the probability that the patient will be prescribed a medication with a pharmacogenomics relationship in the future.
15. A method of selectively conducting pharmacogenomics testing on a multitude of patients, comprising: a) obtaining input data for each of the multitude of patients; b) conducting the method of claim 1 for each of the multitude of patients based on the input data; c) using the predictions P (M) for each of the patients to select a subset of the multitude of patients to subject to pharmacogenomics testing, and d) conducting pharmacogenomics testing for the selected subset of patients.
16. The method of claim 15, wherein steps a), b) and c) are performed daily for each patient of the healthcare provider.
17. The method of claim 15, wherein the input data of step a) comprises one of (a) patient medical record number, or (b) patient identifying information such as name, or number associated with the patient.
18. The method of claim 15, wherein the healthcare provider is at least one of a hospital or medical clinic.
19. The method of claim 18, wherein the healthcare provider is the United States Veterans Administration or a subdivision thereof.
20. An apparatus for determining whether to perform pharmacogenomics testing on a patient, comprising: a user interface comprising a display that is operable by the patient to input information as to diseases they have been diagnosed with or medications they have been prescribed; a processing system configured to implement an applications programming interface that provides the information entered in the user interface to the computer of claim 8, wherein the information entered in the toot user interface is converted by the applications programming interface to the input data set for the computer, wherein the user interface is also configured to report, to the patient, the prediction generated by the computer.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION
[0022] As explained above, while pre-emptive PGx testing for all patients in a particular healthcare system could bring precision medicine at a population health level, the scarcity of resources and the need for economic efficiency calls for a tool that could stratify patients by the potential utility of this type of genetic testing. The innovation represented by this disclosure enables this ability to stratify patients for potential utility of PGx testing. It has the potential to accelerate the adoption of pharmacogenomics by increasing the yield of actionable results, which in turn could increase the engagement of clinicians and patients to this emerging field and bring the benefits of PGx testing to a much wider number of patients. Further, no blood test, genomic test, or other physically invasive test need be done to conduct the method of this disclosure, rather all is needed is information from the patient's electronic medical record.
[0023] As will be explained below, the primary end user of the system and method of this disclosure (MAPPeR for shorthand) would be a healthcare provider who could use it to identify which patients have the most immediate potential to benefit from PGx testing. Specific end users could be primary care providers at hospitals and clinics and physicians participating PHASeR programs in VA medical centers and the VA in general. PHASeR (PHarmacogenomic Action for cancer SuRvivorship) is a program funded by philanthropist Denny Sanford to provide free genetic testing for up to 250,000 veterans through a partnership between Sanford Health, the assignee of this invention, and the VA. Of course, the MAPPeR tools and methods are generally applicable to other medical systems and hospitals.
[0024] Healthcare providers could essentially match their patients from their clinic schedule each day to see whom they should recommend having PGx testing, by preforming the methods of this disclosure on a regular, e.g., daily basis, as will be described in conjunction with
[0025] Another potential user of a version of MAPPeR could be patients themselves. An API could be set up with already available tools like the CMS Blue Button to allow patients to enter their own information via a suitable user interface (e.g. a web browser); the information entered prompts extraction of the input data needed for the Bayesian network and a prediction is generated by the Bayesian network and reported back to the patient in substantial real time. This would allow the patient to see if PGx testing would have potential benefit for them. This would empower patients to have conversations with their healthcare providers and request PGx testing.
[0026] Referring now to
[0027] This input data set 100 is provided to the computer 120 and in particular a Bayesian network 124 is constructed and implemented in the computer. The network 123 generates an output 126 in the form of a prediction or recommendation for PGx testing as will be explained below. This Bayesian network 124 (see
[0028] (1) a disease status partition 202 having as elements 203, 205, 207 etc. representing one or more independent diseases of the patient, there being up to N such diseases, where N is some integer greater than or equal to 1;
[0029] (2) a medications partition 204 have as elements 211, 213, 215 etc. medications that are associated with one or more of the elements 203, 205, 207 etc. of the disease status partition 202, or are medications which have been prescribed for the patient; and
[0030] (3) a genetics partition 206 (which could also be called “biomarker”, “actionable alleles” etc.) having as elements 232, 234, 236 etc. particular genes with alleles 232 (variants of the gene) which may have an established pharmacogenomics relationship with one or more the elements in the medications partition 204. It will be appreciated that as pharmacogenomics research progresses the content of the genetics partition 206 may expand over time to reflect new discoveries between genetic variants and response to pharmacological products.
[0031] The weights of links 210, 212, 214, 216 etc. between the disease status partition 202 and the medications partition 204 are based on an analysis of a large corpus of patient data which includes prescribed medications and disease diagnosis. This will be discussed in more detail below. In
[0032] Our method then continues with step (c) of generating (i.e., calculating) from the Bayesian network of
Discussion
[0033] In our approach shown in
[0034] Our method also provides a directed link from disease status to medication prescription to PGx biomarkers, as indicated by the three partitions of
[0035] The Bayesian network 124 that lies at the core of the MAPPeR program can be broken down into a tripartite graph as shown in
and
where P(Mi|D.sub.i) is the weight of each link between the disease status and medications partitions.
[0036] The variable G.sub.i,j, just represents the existing of a pharmacogenomics link between Gene k and Medication i. If there is a link, this value is 1; if not, it is 0. The probability will be 0 only in the event that the particular medication is not linked to any significant PGx biomarker/gene.
[0037] An assumption is built into Equation 1 that the events of being prescribed the medication given a single disease are independent (i.e. P ((M|D.sub.i)∩(M|D.sub.j))=P(M|D.sub.i)*P(M|D.sub.j)).
[0038] The links between medication and PGx biomarkers (220, 222) are binary representations of a direct connection determined by a combination of the guidelines established by the Clinical Pharmacogenetic Implementation Consortium (CPIC), see https://cpicpgx.org/guidelines/, and the FDAs Table of Pharmacogenomic Biomarkers in Drug Labeling. See gttps://www.fda.gov/drugs/science-and-research-drugs/table-pharmacogenomic-biomarkers-drug-labeling.
[0039] The probabilistic disease-to-medication mapping (represented by the links 210, 212, 214, etc. and the binary linkage from medications to PGx biomarkers (220, 222) are combined to form the core Bayesian network of the MAPPeR test method, using Equation 1 to calculate the probability P(M).
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[0042] The indication of PGx relevance comes from having an above-threshold probability for any of the specific medications that have PGx relevance. It is possible to generate a single value to represent their probability of benefiting from PGx testing, especially Equation (1) integrates more information such as the likelihood of allele presence. Alternatively, the value could be represented by the calculation for the probability P of medication prescription: Equation (2) P=1−(π.sub.i1−P(M.sub.i)),M.sub.i ϵ M, where M is the set of all medications for which the patient has an above-threshold probability estimate. P could be the patient's PGx score, essentially.
[0043] The probability of each medication is calculated given the disease profile available for that patient. The probabilities for Warfarin being prescribed and Clopidogrel being prescribed, given the disease profile of I48 and I25 are fairly straightforward, as they have only one link. The probabilities are thus the single weight of the edge connecting I48 to Warfarin and I25 to Clopidogrel. For Ticagrelor, the probability is the combination of probabilities of either I48 or I25 or both resulting in Ticagrelor being prescribed. The prescriptions are assumed to be independent, so they can be calculated through a product of the events. P(Ticagrelor|[I48, I25])=P(Ticagrelor|I48)*P(Ticagrelor|I25)+P(Ticagrelor|I48)*P(No Ticagrelor|I25)+P(No Ticagrelor|I48)*P(Ticagrelor|I25). An alternative method for performing the calculation is that the result is just the compliment of both disease diagnoses not resulting in a Ticagrelor prescription: P(Ticagrelor|[I48, I25])=1−P(No Ticagrelor|I48)*P(No Ticagrelor|I25)=1−(1−0.24)(1−0.05)=1−(0.76)(0.95)=1−0.722=0.278. If there were more disease diagnoses present that result in a Ticagrelor prescription, the complimentary probability of that linkage (p) would just be added into the product [1−(0.76)(0.95)(1−p)].
Validation
[0044] Primary validation of MAPPeR involved assessment of the performance of the disease-to-medication mapping (i.e., the links and weights between the disease status partition 202 and the medications partition 204,
[0045] Second, a similar binomial hypothesis-based approach was used to assess the performance of the mapping system on external data. The disease-to-medication mapping was constructed using the entire set of patient data and tested against a set of 170 records from patients in the VA Precision Oncology Cohort A, which was obtained as part of the VA's Al Tech Sprint. External consistency was determined similarly as the internal consistency, with a binomial hypothesis test performed for each of the links between disease and medication. In this assessment, 97.4% of the links were found to be consistent between the mapping and VA patient data.
[0046] Lastly, a rigorous assessment of the disease-to-medication mapping was carried out by varying the operational threshold used to define a reliable mapping from disease diagnosis to medication prescription. For this evaluation, operational thresholds of the posterior probability were varied from 0 to 1, which resulted in an Area Under the Receiver
[0047] Operating Characteristic Curve (AUC) of 0.737. An optimal operational threshold identified as that closes to perfect performance (Sensitivity=1.0, Specificity=1.0) was determined to be 0.01, corresponding to a 0.562 sensitivity, 0.889 specificity, and 10.259 Diagnostic Odds Ratio. Thus, this threshold 0.01 can be used to make the recommendation of whether or not the patient is likely to benefit from a PGx test, where if the probability P(M) is at or above the threshold the test is recommended.
[0048] It is possible to add additional layers of predictive value to our method to make it more sensitive to potential impact of PGx testing and guide the end user in a more nuanced way. For example, we could factor in not just existing ICD-10 codes for existing diseases but also disease risk calculations based on any other relevant clinical data. This would add even more pre-emptive value by noting the likelihood of needing a medication before a disease state has even arisen. Another example would be to weight the likelihood of having an actionable genetic variant based on the prevalence of that genetic variant in the population. Thus, PGx testing may be more or less likely to bring value if the genetic variant in question for a particular drug is more or less prevalent. Disease risk prediction would provide a little more predictive value to the disease status information, i.e. we could preemptively determine what diseases they may experience in a given time frame. The allele likelihoods would not be integrated into the Bayesian network, but they would also help determine the PGx recommendation, in conjunction with predicted medications. For PGx to be useful, a patient needs to be prescribed particular medications and have specific allele(s) related to medication. These two things together will make the results of a PGx test useful. The allele likelihoods would be connected to the predicted medications to make a recommendation. Essentially, a patient might be predicted to be prescribed Codeine, but unless there is some degree of certainty they will have a CYP2D6 variation, the PGx test would not be all that useful.
Further Considerations
[0049] Our current implementation of MAPPeR uses a server constructed using a Shiny application user interface. Our planned implementation would include improving the user interface and adding connectivity to CMS Blue Button and VA Health API.
[0050] In one configuration, implementation into clinical care would come with integration into the clinical practice at a hospital or medical center, and/or the Veterans Administration (VA) or subdivision thereof. We can integrate the backend of MAPPeR into an electronic medical record and test various approaches to alerting a provider that a patient meets the PGx criteria. In addition to adding layers to make the clinical prediction model more sophisticated, interfacing with the EMR can make the whole process more automated so that a provider could be a more passive participant rather than having to affirmatively enter in a patient's data. Thus, MAPPeR would always be working in the background and only alert a provider when they are actively seeing a patient who would benefit from testing.
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[0053] As noted in
[0054] The appended claims are offered as further descriptions of the disclosed inventions. All questions concerning scope are to be answered by reference to the appended claims.