Many professions rely on the decisions of skilled professionals in order to yield successful results. For example, during almost every patient visit, medical professionals must make decisions regarding whether or not to require a particular course of action for the patient. Based on the results of a test, a physician will typically decide whether to order additional tests, whether to recommend a course of treatment, or whether to maintain the status quo. In highly complex professions such as medicine, professionals may be faced with a vast quantity of data and have difficulty determining which of the data is relevant to a decision.
When a patient is suspected of having a type of disease, e.g. heart disease or cancer, the clinical issues become finding the sub-type of disease and recommending the optimal treatment plan. Examples of a disease sub-type for heart disease might be a patient with valvular disease or a patient with stenotic coronary arteries, each requiring different and unique treatment plans. For each suspected disease type, the patient typically undergoes a series of diagnostic tests. In some instances, the series of tests are designed to eliminate patients from undergoing the most expensive or most invasive test, i.e., if the “lower order” tests do not detect the presence of the disease sub-type, then the patient will not progress through the full series of tests. For a patient suspected of coronary artery disease, coronary artery catheterization is regarded by some as the definitive test (i.e. the “gold standard”), but the patient will typically undergo several blood level tests and a myocardial perfusion test prior to catheterization. Only if the patient exhibits sufficient evidence of disease on these lower order tests will they progress to a catheterization suite of tests.
When the catheterization test is performed, the lower order test results are often discounted as the catheterization test is regarded as the gold standard in this example, thus resulting in the wasted expense for the discounted tests incurred by the patient or the patient's insurer. However, there are several drawbacks to this approach: 1) the lower order tests may miss disease, and thus cause treatment to be withheld; 2) even the gold standard test may misdiagnose patients as having too low a level of disease to treat effectively; 3) the results from the lower order tests often do not contribute to the further management of the patient after the gold standard test is performed; 4) often, if the suspicion of disease is high, not all the lower order tests are performed, again discounting their ability to contribute to further patient management; and 5) it is quite typical for many patients to have similar values of several lower order tests, e.g. systolic blood pressure and blood cholesterol levels in some mildly unfavorable range, and for it to be observed that the patients experience different outcomes despite these similarities.
Additionally, treatment of patients is governed by evidence-based approaches typically overseen by professional bodies. However, the guidelines for initiating treatment are typically based on population averages, and thus some patients are over-treated, and are at risk of experiencing adverse side effects. Conversely, some patients are under-treated, and thus are at risk of suffering a severe adverse outcome that may have been treatable if the patients were properly treated. The typical paradigm for making decisions of when to initiate treatment are based on the patient attaining a certain extent of disease, e.g., reaching a systolic blood pressure of 140 mmHg, reaching a blood lipid level of 100, or having other similar test results that may indicate an extent of a disease. However, as discussed above, professionals may be faced with a vast quantity of data and have difficulty determining which of the data is relevant to a decision related to disease extent, and thus may be prone to misdiagnosing and fail to deliver a proper level of treatment.
In one general respect, a first embodiment discloses a method for ordering and arranging a data set. The method includes accessing a data set of patient data, wherein the data for each patient includes a set of diagnostic test values and one or more outcomes; retrieving, from the data set, a first patient data set that corresponds to a first outcome; selecting a first set of the diagnostic test values from the first patient data set; normalizing the first set of diagnostic test values to cover a range; ordering the normalized first set of diagnostic test values such that a low-frequency content plot is derived; creating a first equation describing the ordered data of the first patient data set for the normalized first set of diagnostic test values; retrieving, from the data set, a second patient data set that corresponds to a second outcome; selecting, a second set of diagnostic test value from the second patient data set; normalizing the second set of diagnostic test values to cover a range; ordering the normalized second set of diagnostic test values; creating a second equation describing the ordered data of the second patient data set for the normalized second set of diagnostic test values; and comparing the first and second equations.
In another general respect, a second embodiment discloses a system for ordering and arranging a data set. The system includes a processing device and a non-transitory computer readable medium operably connected to the processor, the computer readable medium containing a set of instructions. The instructions are configured to cause the processing device to access a data set of patient data, wherein the data for each patient includes a set of diagnostic test values and one or more outcomes; retrieve, from the data set, a first patient data set that corresponds to a first outcome; select a first set of the diagnostic test values from the first patient data set; normalize the first set of diagnostic test values to cover a range; order the normalized first set of diagnostic test values such that a low-frequency content plot is derived; create a first equation describing the ordered data of the first patient data set for the normalized first set of diagnostic test values; retrieve, from the data set, a second patient data set that corresponds to a second outcome; select a second set of diagnostic test value from the second patient data set; normalize the second set of diagnostic test values to cover a range; order the normalized second set of diagnostic test values; create a second equation describing the ordered data of the second patient data set for the normalized second set of diagnostic test values, and compare the first and second equations.
a illustrates a time ordered sampling of a sinusoidal waveform.
b illustrates a random sampling of a sinusoidal waveform.
c illustrates a time ordered sampling of a sinusoidal waveform including interpolated data points.
This disclosure is not limited to the particular systems, devices and methods described, as these may vary. The terminology used in the description is for the purpose of describing the particular versions or embodiments only, and is not intended to limit the scope.
As used in this document, the singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art. As used in this document, the term “comprising” means “including, but not limited to.” As used in this document, the terms “sum,” “product” and similar mathematical terms are construed broadly to include any method or algorithm in which a single datum is derived or calculated from a plurality of input data.
As used herein, the term “modality” refers to a mode, process or method of obtaining a set of data. For example, a modality may include a specific medical test or imaging process wherein one or more sets of patient specific data are obtained.
Typically, when a human makes a decision, the person relies upon some set of known facts or concrete evidence. However, this set of known facts may not include all necessary information required to make the decision. Thus, the person must use some amount of judgment when making the decision.
One example of an area where a person such as a medical provider makes a decision without a full set of data is in determining disease sub-type and an associated treatment plan. Using the processes and techniques as taught herein, a medical provider may make a more informed decision as to an appropriate treatment plan for a patient.
This disclosure is complementary to prior processes DICE and DICIE as taught in the related U.S. patent application Ser. No. 13/289,335, the disclosure of which is hereby incorporated by reference, but is not dependent on such processes. The approach as taught herein, referred to as Severity and Heterogeneity Approach to Preventing Events (SHAPE) arranges data that forms part of the medical record of a patient in an order that allows characterization of that patient with regard to disease sub-type and severity, i.e., the ordered data forms a characteristic shape associated with each disease sub-type within the context of a hierarchical scheme or stratification the diseases.
By using the characterization scheme of SHAPE, derived from previously evaluated patient groups, a suitable treatment or treatment plan can be recommended for a current patient. Further, since the medical data are arranged in an ordered manner, and the plot of that data forms a characteristic shape, then there is the potential to eliminate some of the data and still adequately characterize the disease sub-type of the patient. This aspect either allows improved characterization of the patient in the absence of a complete set of diagnostic tests, or, more proactively, it allows an optimal selection of tests, with the aim of omitting the most expensive or invasive tests by design, thereby bringing additional economic benefit.
Typically, a patient is suspected of having a type of disease, e.g., heart disease or cancer, and the clinical issues then become finding the sub-type of disease and recommending the optimal treatment plan. Examples of a disease sub-type for heart disease might be a patient with valvular disease or a patient with stenotic coronary arteries, each requiring quite different treatment strategies. For each suspected disease type, the patient typically undergoes a series of diagnostic tests. In some instances, the series of tests is designed to eliminate patients from undergoing the most expensive or most invasive test, i.e., if the “lower order” tests do not detect the presence of the disease sub-type, then they will not progress through the full series of tests.
In the separate area of signal processing there is often the observation that ordering data in some logical manner better represents the data than a random presentation, and that this ordering of data helps reduce the number of variables needed to characterize the data.
Referring back to
When determining diagnostic medical data, as indicated above, in common practice, the order in which medical tests are performed is governed by the expense and degree of invasiveness of the tests. Further, after a series of tests are performed, more clinical weight is attached to some tests over others, and much information is discarded at the stage of deciding a treatment course for the patient. In SHAPE, the medical data may be arranged in a logical order such that the band-width describing the data is limited and optionally minimized. In this way, less data (i.e., fewer tests) may be acquired or missing data may be accommodated. In one embodiment, the wide variety of data that is entered into SHAPE may be normalized into a common range (e.g. expressing the data using percentages of some physiologic range, such that data typically range from 0 to 100%). For instance, one of the input variables could be a DICE-augmented reading of a diagnostic test. The ordering of the data may be found at an initialization stage by exploration of historical data sets, especially if the treatment and patient outcome of those tests were known. Normalized data from multiple diagnostic tests may be ordered for each patient, and arranged until the shape described by the ordered plot of data underwent some minimization of bandwidth as described above. The data may be plotted graphically for easy human interpretation, but more importantly, the relationship between ordered data is known to the computer system and can be defined by an equation. For example,
The ordering process may be repeated for similar data from multiple patients, until a consensus of ordering was achieved. The intention is that the ordering would identify several distinct groups of patients, each group having a distinct shape of the magnitude of ordered variables (as described by an equation obtained for example by a least-squares fitting criteria). From the observation of outcomes of patients, it would be expected that a patient with some characteristic data shape would experience better outcomes for one particular treatment compared to another applied to patients characterized by the same data shape of curve.
After having made these observations and identified the patient groups and effective treatments, thereafter, the SHAPE ordering of data could be used to guide future therapy and better direct patients as to which diagnostic test would add the most value to characterize their disease sub-type.
Another aspect of the SHAPE tool for correctly determining a treatment plan may be to arrange diseases in a hierarchical scheme or to stratify the diseases.
The SHAPE and stratification techniques as discussed herein involve the ordering and hierarchal structuring of disease components associated with a major disease category, e.g., ischemic heart disease. These concepts may be intuitively represented in a one dimensional (1D) plot or a two-dimensional (2D) radar plot depending on preference. In the radar plot, any essential features may be retained in a visual representation of the data. The hierarchal nature of the data may be represented as a multiplication effect on the plot. Additionally, data may be further compressed by integrating the area in the radar plot.
As shown in
Occasionally, a radar plot for a particular group may be inconclusive based solely upon the SHAPE ordering of information. For example, as shown in
For example, to calculate the multiplication factor, the following criteria may be used: (1) Incorporate the ratio of event rate between patients having a perfusion and those not having a perfusion. In this example, the ratio would be 0.17/0.04=4.6. (2) Incorporate the ratio of the mean area of the positive perfusion plots and the negative perfusion plots=2.6. (3) Determine the hierarchal factor by dividing the event rate ratio by the mean are ratio, 4.6/2.6=1.7. It should be noted these criteria are shown by way of example only.
By determining a multiplication factor, the process may allow for shifting and personalization of thresholds directed to individual patients for determining a treatment plan.
By visually presenting the SHAPE data in a radar or 1D plot, the data may indicate a certain dominant axis to the disease, as well as allowing overall severity of the disease to be visually identified. More importantly, this axis may be found by analysis of the equation describing the SHAPE ordered data. Further, the area of the radar plot may be integrated geometrically to identify disease severity. Additionally, the distribution of events among patients may be analyzed to determine high and low risk groups. For example, critical events may be experienced by patients with a hierarchal SHAPE plot area above 0.05. This threshold may indicate the level where, for patients below the threshold, there may be no impact in event occurrence for those on or off medication. For those above the threshold, there may be a dramatically higher percentage of those off medication experiencing a critical event than those on medication. Thus, the SHAPE ordering of data, combined with the stratification of the data into a hierarchal structure, summarizes the severity of each individual patient. This information may be optionally plotted into a 1D linear or 2D radar plot for visual presentation to the human. SHAPE ordering and stratification also provides a framework to compare groups of patients, such as those that may appear in a clinical study.
The processor may then create 810 a first plot for the first patient based upon the normalized and ordered diagnostic test results. As shown above, the first plot may be a 2D radar plot including a multiplication factor for normalizing the data shown therein.
In order to provide a means for comparing the first patient's information, the medical professional or processor may create 818 a similar second plot for a second patient's data set. Like before, the processor may retrieve 812 a data set related to the second patient and the second patient's present course of treatment. The medical professional and/or the processor may select 814 one or more diagnostic test results from the second patient data set and normalize and order 816 the second set of test results. Optionally, the system may further stratify the data set according to the hierarchal scheme as discussed above.
The processor may the create 818 the second plot for the second patient based upon the second patient set's ordered, normalized test results. The two plots may then be displayed 820 for comparison purposes, allowing the medical professional to evaluate and analyze the current treatment plan for the first patient based upon the historic records associated with the second patient.
It should be noted that while the process as illustrated in
A controller 920 interfaces with one or more optional memory devices 925 to the system bus 900. These memory devices 925 may include, for example, an external or internal DVD drive, a CD ROM drive, a hard drive, flash memory, a USB drive or the like. As indicated previously, these various drives and controllers are optional devices. Additionally, the memory devices 925 may be configured to include individual files for storing any software modules or instructions, auxiliary data, common files for storing groups of results or auxiliary, or one or more databases for storing the result information, auxiliary data, and related information as discussed above.
Program instructions, software or interactive modules for performing the processes as discussed above may be stored in the ROM 910 and/or the RAM 915. Optionally, the program instructions may be stored on a tangible computer readable medium such as a compact disk, a digital disk, flash memory, a memory card, a USB drive, an optical disc storage medium, and/or other recording medium.
An optional display interface 930 may permit information from the bus 900 to be displayed on the display 935 in audio, visual, graphic or alphanumeric format. The information may include information related various data sets. Communication with external devices may occur using various communication ports 940. A communication port 940 may be attached to a communications network, such as the Internet or an intranet.
The hardware may also include an interface 945 which allows for receipt of data from input devices such as a keyboard 950 or other input device 955 such as a mouse, a joystick, a touch screen, a remote control, a pointing device, a video input device and/or an audio input device.
Several of the above-disclosed and other features and functions, or alternatives thereof, may be combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art, each of which is also intended to be encompassed by the disclosed embodiments.
This application is a national stage application of, and claims priority to, International Patent Application No. PCT/US2013/042462, filed May 23, 2013, which in turn claims priority to U.S. Provisional Application No. 61/651,114 filed May 24, 2012 entitled “Method and System for Ordering and Arranging a Data Set for a Severity and Heterogeneity Approach to Preventing Events Including a Disease Stratification Scheme,” the content of which is hereby incorporated by reference in its entirety.
Filing Document | Filing Date | Country | Kind |
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PCT/US13/42462 | 5/23/2013 | WO | 00 |
Number | Date | Country | |
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61651114 | May 2012 | US |