STATworkUP is a medical application for iOS iPhone, iPad, iPod touch and Mac. It runs on Android smart phones and tablets too. This app is designed to support the diagnostic process. Because its user interface parallels typical methods of clinical investigation, its operation is fairly intuitive for health care providers.
Clinical medicine is an artistic and philosophic discipline combining scientific skill. Adept and competent practice requires years of training and experience plus lots of insightful wisdom. Although STATworkUP is not intended to supplant sound medical judgment, it is a modern tool for rapid decision support, easy to understand, adapt and use. It includes a big knowledge database for multiple specialties that is frequently updated. STATworkUP contains a collection of evidence-based facts and correlations for quick review of many details to guide comprehensive history-taking and physical examination of the patient, plus supportive studies.
STATworkUP presents the essential criteria to help you determine diagnoses. It also can sharpen skills by shifting focus from the chief complaint to provide a wider spectrum of considerations in valuable and useful ways. By providing quick information, at your fingertips, it helps to save time and gain practice efficiencies. The app can be helpful for utilization review activities and reference. Ultimately, it may also improve the quality of outcomes and save on the costs of healthcare delivery.
Its features can be used to explore and evaluate conditions for fast problem assessment. Correlation panels, drill-down information views, and a web mode assist in associating symptoms and studies with diagnoses and treatments. As workup proceeds, the program instantly adjusts the differential diagnoses list to fit with selected findings.
Signs and symptoms of many disorders can be similar to those of other conditions. That can make diagnosis challenging. Usually early detection of disease is important to derive the benefits of treatments and prevent complications. Symptoms can wax and wane during the course of an illness. Sometimes they are similar to initial findings that occurred and may represent a recurrence of the condition or a flareup. At other times new signs and symptoms indicate progression or exacerbation of a disease or complications of it or its treatments. STATworkUP quickly reveals the types of complications that can occur during many diseases and treatments. It includes the signs and symptoms they can share in common and shows their possible causes too.
You can use STATworkUP tables to rapidly search for symptoms or signs. It can be voice activated. And it recognizes synonyms too. Simply checkmark listed items to designate them as findings. Drill-down to detailed info views where you can tap the correlate button. It instantly presents a panel of additional choices to build lists of contextual events or situations. These can be significant attributes of other possible disorders. The app also produces lists of appropriate diagnostic lab tests to examine, analyze and scrutinize. Those investigations may be pertinent to help validate and corroborate assumptions or clarify impressions. During assessment the combined weights of designated findings justify and produce resulting differential diagnoses for consideration.
This app has the power to generate prioritized or alphabetized tables of conditions for the set of findings that you place on its Findings list. And each differential diagnosis table that it calculates can be expanded or constrained to loosen or tighten the fit of the listed diagnoses for the signified findings by simply adjusting a likelihood meter. It is quite easy to use. Additionally, STATworkUP provides swift, concise and relevant info for each of more than 13,000 entities in the database. It can automatically search for links to subject matter expert web-pages, with graphics and videos, to view more in-depth content for study, review, learning and evaluation. Content and app help can also be printed. Every effort has been taken to conform to standard practices and guidelines in both the medical and computing industries. The authors include physicians, engineers, mathematicians and medical informaticists. We sincerely hope you will enjoy using it.
What It Does Not Do ...
Although the program calculates a range of diagnostic possibilities for finding selections, it does not interpret symptom complexes, nor perform synthesis of information, based on quality, magnitude or temporalspatial relationships. Those subtle, albeit important, considerations require the user's keen medical insight. Such special factors and determinations presently transcend this program's scope.
For these reasons STATworkUP is an interactive application requiring discretion and awareness of its limitations. Again, this application is NOT intended to supplant expertise when performing medical practice. It is just a quick reference that should be a helpful tool for those who are prepared to provide medical care.
To preserve confidentiality, reports of the workup cannot be produced or printed with this version. The database cannot be modified either. Updates are often available and you will be notified when they are ready for installation.
How To Use It ...
STATworkUP is a useful mobile medical app that can help guide quick and comprehensive history and physical exam assessments during evaluation of problems encountered in most clinical settings. It includes a large, robust and fully relational multispecialty database that has been carefully crafted by a team of well qualified doctors and computer engineers. The content and design is frequently updated to reflect current best practices, and keep it relevant, fast, and easy to use. It works in either portrait or landscape orientation on the iPhone, iPad or iPod touch. And it can be used on Android smart phones and tablets. Plus it also runs on Mac computers. For optimal speed and performance we recommend using the latest operating system on compatible devices. Reading the help document is useful to get the most value from STATworkUP. Yet, many want to jump right in and begin exploring. So, here are a few pointers and tips to help you get started:
This application has four tables that are each packed full of Symptoms (Sx), Studies (Lab), Diagnoses (Dx) or Treatments (Rx). Tab bar buttons, at the bottom of most views, open each corresponding table when selected. Their lists of sub-categorized names are alphabetized. Additionally, each table view has a button shaped like a magnifying glass on the navigation bar. Tap on that button to open or close the search and scope tools. Use these search functions to quickly locate items on each table. They are quite versatile for retrieving words from the apps core data structure. For instance, open the Diagnosis table view and enter 'Heart' into the table's search field to create a list of cardiac disorders. Or enter the word 'Emergency' to build a list of urgent or life-threatening situations that may require rapid or prompt intervention. Voice-activated search is also possible. And you can also find things by entering just part of a name manually. On the Android version a scope bar can be used to filter table searches by Title, Subtitle or All. For instance, it can be used to find all words that start with the letter 'R' by entering 'R' into the search field when the Scope Title button is selected. And the Android version of STATworkUP also contains a drop-down menu of items to open various views, (instead of tab items.)
To see detailed INFO views for table items, simply drill-down on cells. The selected item will appear in white on a gradient-tinted name field at the top of the INFO view, just below the navigation bar. These views may include concisely detailed information, like definitions, etiologies, epidemiology, manifestations, onset, prevalence, incidence, occurrence, risk factors, associations, complications and prognoses. And Treatment table item Info views may show generic and proprietary drug names, properties, medication classifications, actions and interactions, indications, contraindications, off-label uses, side-effects, precautions and warnings.
The embedded INFO content is helpful in the Airport Mode, or in situations when you are not within WiFi or network range. Additionally, associated subject matter expert web pages can be accessed when the device is connected to the internet. Just tap the ("Web") button on the navigation bar of any Info view to get a list of related links. When you are done browsing simply tap the "Done", or go back, button to return to the view you were at previously.
STATworkUP is designed to correlate each database item. Its cross-referencing capability is quite powerful so please do not overlook this feature while you explore the app. To harness these useful functions drill-down to INFO views by tapping on table items. Then touch the CORRELATE button which is present on the tool bar, right above the tab bar. When the CORRELATE button is tapped a correlation panel of additional buttons will pop-up. That facilitates choosing various pathways of investigation.
For example, select the Symptoms (Sx) table. If you drill-down to an item's INFO view and touch its CORRELATE button, the correlation panel shows SIGNS & SX, DDX, WORKUP, and RX SIDE EFFECTS buttons.
As another example, open the Studies (Lab) table. When you drill down to a listed item's INFO view and tap the CORRELATE button its Correlation Panel has SIGNS & SX and WORKUP buttons.
As yet another example, select the Diagnoses (Dx) table. Drill down on any item to the INFO view. When the CORRELATE button is touched its correlation panel of buttons include CAUSES, COMPLICATIONS, WORKUP, REMEDIES, RX RISKS and RX CONTRAINDICATIONS. It also includes Diagnostic SIGNS & SX. Tapping on that button reveals history and physical items, or the results of lab studies. Signs and Symptoms can be checkmarked to designate them as FINDINGS that can lend their diagnostic weight. Now, Go back to the previous view by tapping the Info button on the Left side of the top Navigation bar.
Last, go to the Treatment (Rx) table and drill-down to any cell's Info View. Tapping its CORRELATE button will pop-up a Correlation Panel of buttons that include RX INDICATIONS, RX SIDE EFFECTS, RX INTERACTIONS, RX COMPLICATIONS and RX CONTRAINDICATIONS.
Next, open the DIAGNOSES (Dx) table again and drill-down on a cell to see its INFO view. Then tap on the CORRELATE button. It will pop-up a Correlation panel that includes a "SIGNS & SX" button. When tapped it builds a set of potentially relevant HISTORY or PHYSICAL findings for further evaluation. The alphabetized list of Signs & Sx is displayed below a tinted name bar that appears under the upper black navigation bar of INFO views. Those can be especially pertinent to focus on during your investigation. Each tabled SIGNS & SX item can be checkmarked to designate it as a Finding or not. Just touch adjacent checkmark fields to toggle it on or off. That is all you need to do to signify that the correlated Sign or Symptom is a Finding. When checked, each designated Finding instantly conveys its weight to related diagnosis in the database structure. Turning a checkmark off removes the Finding's weight from calculation of possible related diagnoses. In this way the app quickly computes corresponding sets of related disorders or conditions for checkmarked Findings. (Read more about how the program does this in the Help section called Calculations.)
The program rapidly aggregates collective combinations of Finding weights and simultaneously integrates them to produce Differential Diagnoses for the Findings you select during workup.
To quickly build a view of all the checked Findings simply tap on the FINDINGS button. It is present on the tool bar above the lower tab bar. Tapping that button builds a list for all selected findings. (A FINDINGS list). If no Findings have been checkmarked then an alert will pop up that will advise you to select at least one symptom. Individual findings can be cleared from the Findings list. Just back-swipe a listed finding and tap on the Delete button that subsequently appears at the right side of the selected Finding's list cell. Additionally, all of the listed findings in the Findings view can be removed by tapping on the CLEAR button. It is present on the upper navigation bar. However, be aware that doing this returns all of the checked findings to an unchecked state everywhere else in the app. Clearing the Findings table removes the impact of listed Findings as corroborative Diagnostic attributes. Doing so removes the significant contributory Finding weights that are used to calculate and determine the array of differential diagnosis. As a result the diagnostic differential list will be emptied when all of the Findings are cleared from the Findings List.
This application does not currently save the workup when the Findings list is cleared. And there is no way to save findings with personally identifiable information in this version. That feature is being considered for future updates. When you quit the application without clearing findings from the Findings list, they are saved for the next session. In that situation, upon launch an alert asks whether to continue the prior workup in progress or to delete it. Deleting erases the checked Findings and empties the Findings list. Continue returns to the workup with the Findings checked as they were when you last exited the app.
Possible diagnoses that are associated with the collection of checked findings can be viewed by tapping the DIFFERENTIAL button. It is located above the tab bar on the tool bar. A sliding control meter is present in the Differential view to adjust the fit of diagnoses for all of the selected findings. Moving the slider control setting toward the more likely side of the meter generally constrains the list to show better fit diagnoses. Moving the slider control setting in the other direction, toward the less likely side of the meter, usually expands the list, showing more diagnoses that may not be as likely, based upon the total weighting of all selected findings when compared to that setting.
A PRIORITIZE switch is present in the Differential view to sort listed Diagnoses. When PRIORITIZE is selected more probable diagnoses for findings are shown near the top of the list and less probable one appear toward the bottom of the list. The array of diagnoses is sorted alphabetically when the switch is toggled to ALPHABETIZE. Of course, when no findings are checked at all the Differential list of Diagnoses will be empty.
Now, go ahead and try using STATworkUP to assess some problems. There are a lot of ways to correlate the many entities that are contained in its big database. Related DDX can be listed for any selected Sign or Symptom. Tests that may be appropriate during the workup of Symptoms or Diagnoses items can also be displayed when the WORKUP correlation panel buttons are tapped. Remedies can be shown for Diagnoses too. Remember to return to the INFO views to get back to the Correlate button at any time during assisted problem evaluations.
This medical app derives corroborated lists of possible diagnoses for mindful consideration. And it presents a lot of useful correlations that can facilitate utilization review too. But, also keep in mind that STATworkUP is NOT intended to supplant sound medical judgment! Appropriate practices require years of training plus ample experience and insight. The great amount of good information that it contains for quality assurance should not be substituted for the expert advice of licensed physicians or other healthcare providers during clinical decision-making.
When new databases are ready to update STATworkUP, alerts will notify users. Have fun with this universal iPhone and iPad app and send us your comments about the things that you would like to see in future versions. Please write a review for us and let your colleagues know about this product too. (You can find links to our web sites in the credits section.)
Getting Started With It ...
To begin, choose something to evaluate. Just tap the tab bar button or menu item named Symptoms. A full list of symptoms and signs will populate the table. Then use the table's search bar to quickly find things. The app's search functions are very fast and powerful. A search field will open when you tap the table's navigation bar search icon. You can locate listed words in many different ways by searching for synonyms, or even for parts of names. For instance, enter "eye" to see ocular entities or "heart" to generate a list of cardiovascular conditions. A filter icon is also present on each table's navigation bar when the search field is empty. If the filter icon is tapped a drop-down menu appears. Filter menu selections help to shorten Sx, Lab or Dx tables into listings derived from specialty areas of the database. They can also be used to sort the Rx tables by various treatment categories.
You can quickly see detailed overviews of information for any listed item. Just tap the drill-down control at the right side of the list cell to get to the corresponding Info view. The name of the selected list item will appear in a gray header just below the navigation bar in Info views. Web page links for selected list items can also be browsed by tapping on the ("Web") button in Info view navigation bars. When done browsing the Web simply tap the "Done" button to return to the prior Info view. Use the navigation bar breadcrumb buttons to get back to previous views.
A CORRELATE button is also present above the tab bar in Info views for further analysis. Tapping the CORRELATE button will pop open a display panel of other buttons to cross-relate things that can be associated with the name on the header bar. These things may be pertinent to focus on during examination. Try the encompassing design of the Correlation panel to view the many possible relationships. It is rather easy to see how it works. Use this feature to derive fast associations that may help resolve complexities and guide problem assessments or evaluations. You can correlate signs and symptoms, workup tests, diagnoses and management remedies that might be of interest to review during the encounter. For instance, other possible signs or symptoms can be listed that may be important to consider during investigation of each problem or situation. Diagnostic conditions and other pertinent symptoms or appropriate studies can be shown for consideration too. Similar functions are available for other entities; Including causes and complications for diagnoses or indications, side-effects, interactions, risks and contraindications for treatments.
Related conditions that may be diagnoses for each symptom or study, are instantly listed as correlation panel buttons are tapped. We encourage you to experiment with the myriad possible options to get an idea of what happens. It is quite dynamic, producing very useful relationships for quick reference. STATworkUP can help you to perform fast, yet comprehensive evaluation of many problems and assist you in resolving complex situations.
Any listed manifestation can easily be designated as a Finding during the workup. To add a symptom's diagnostic weight, simply toggle its adjacent checkmark button on. Unchecking a finding instantly removes its weight as an attribute of related diagnoses. To view a list of all of the checked findings during the workup simply tap the FINDINGS button. (It is present above the tab bar in almost all of the views.) If you want to set all checked findings to off, just tap on the Clear button in the Findings view navigation bar (or the Findings waste basket icon in the Android version of STATworkUP.) But be cautioned, if you do this, the selected findings are not saved. Individual findings can be removed from the Findings list view by back-swiping a listed item and then tapping on the resulting Delete button. The item is unchecked everywhere and its diagnostic weight is removed as well.
Diagnostic possibilities for combined findings can be displayed during the workup. You can see them by selecting the DIFFERENTIAL button, present above the tab bars and at the bottom of the Findings view. Diagnoses that are corroborated by findings are listed. You can adjust their fit to the selected findings by setting the sliding probability meter to more or less likely. That can be done in the Differential view. The list can also be prioritized and sorted by most-to-least likely diagnosis for the check-marked findings.
(See the Calculations section of Help to get an understanding of how the differential diagnoses are computed for the designated Findings.)
Problem Workup ...
This application integrates many symptoms (history and physical signs), studies and diagnoses for evaluation. Diagnostically relevant findings for conditions can quickly be collected together. Appropriate tests for workup of various problems can immediately be gathered and presented too. As each symptom, study or diagnosis is selected, related information is rapidly shown to widen the perspective. This can help shift focus from the chief complaint to other contributory, yet perhaps less obvious situations for further investigation or consideration.
Differential Diagnoses for each Symptom, Sign or Finding in the database can be quickly viewed. Symptoms can be check marked to signify them as findings during a problem-oriented assessment. Findings may corroborate possible diagnoses. STATworkUP instantly adds each finding's supportive weight to justify related diagnoses for inclusion in the DIFFERENTIAL view list of resulting diagnoses. The diagnoses can be sorted from most-to-least likely by setting a control button in that view to Prioritize them. Switch the button to Alphabetize to display the listed diagnoses in the Differential view alphabetically.
Of course, discretion is required when deciding what to do with all of this useful information. STATworkUP is not intended to supplant sound medical judgment. So please keep that is mind.
Cross-Referencing ...
Dynamic functions correlate manifestations, tests or remedies for many disorders. Just choose a tab item to build a full list of Symptoms, Studies, Diagnoses or Treatments. Then select something to evaluate from the list. Upon drill-down, fast information for the selection is presented in Info views. The name of the item appears just below the navigation bar and right above its information content. Next, tap on the CORRELATE button that appears above the info view tab bar. That will reveal a panel of more buttons to build additional relationships for the selected item. Many combinations are possible for focused assessment and further review. Try it out.
STATworkUP provides a comprehensive set of correlations for facilitate rapid reference and review. The app can be a helpful tool when exploring symptoms, signs or tests for fast workup and evaluation of diagnoses. It rapidly points out diagnostically significant, relevant and pertinent findings that are associated with various conditions. And it instantly shows appropriate studies for more than 3,000 diagnoses in its database. STATworkUP quickly reveals potential causes and complications for diagnoses. It generates lists of remedies for conditions too; quickly building lists of indications, side-effects, interations, complications and contraindications for treatments as well.
The program integrates many viewpoints for problem analysis. It also keeps track of findings designated by symptom checkmarks. A list of those appears by tapping on the Findings button, just above the tab bar in table views. All of these relationships can be correlated for a quick analysis and evaluation. At any point during the workup just tap the DIFFERENTIAL button to view the possible diagnoses for the findings. That button is present above the tab bar in most views.
In addition to the above functions, there is also a "Web" button (or Globe icon on Android device) on the navigation bar of Info windows. Tapping on that button transitions to a browser view of web-links for the selected item to get even more details. Links to other sites are provided for information only. They do not constitute endorsements of those other sites.
Selecting Findings ...
STATworkUP not only correlates potential Findings for symptoms, studies or diagnoses, but it also derives views of their causes or conditions for further consideration. The app can build DIFFERENTIAL lists of Diagnoses that share symptoms or signs in common. A control button appears next to each cell on the Symptoms table. These can be toggled on or off to respectively add or remove their diagnostic weighting for diagnoses in the apps database. The checked state indicates that a symptom has been designated as a Finding during the workup.
Findings contribute some portion of the best weight to associated diagnoses to which they portend. The amount of weight that is conveyed to each related diagnosis depends on how many diagnoses share each finding as a potential attribute. If all of the signs or symptoms for a diagnosis were selected then that would constitute the aggregate best weight for that diagnosis. However, that would be unusual. Typically only part of a conditions best weight is present because only some of its symptoms are manifest. The sum of finding weights for a diagnosis is called the actual weight of the findings for each related diagnosis. Some diagnoses share different numbers of findings, and the amounts of their aggregated finding weights, than do others. Listed conditions are compared to their individual best possible diagnostic collective weights and are arranged in the DIFFERENTIAL array the that button is tapped.
STATworkUP instantly compares the actual finding weights selected to the best weight for each diagnosis and computes a list of diagnoses for consideration. These are shown whenever the DIFFERENTIAL button is selected, unless no symptoms have been checkmarked as findings. In such a case the Differential table will be empty and an alert will pop up that advises you to select at least one symptom. As more findings are selected the differential diagnoses list grows and it shrinks when less findings are noted. Diagnoses in the Differential view are determined based on the combined weights of checkmarked findings. A sliding control meter is present in the Differential view. It can be adjusted to vary the likelihood of possible diagnoses that fit with the selected group of findings. The resulting differential list can be sorted with priority or it can be shown alphabetically. The array of listed diagnoses are displayed from more likely at the top to less likely at the bottom when the DIFFERENTIAL table is prioritized.
A FINDINGS button is present above the tab bar of Sx, Lab, Dx and Rx table views. Tapping that button builds a list of all the checkmarked Findings. If no symptoms have been checkmarked as Findings the Differential table will be empty and an alert will pop up that advises you to checkmark a least one symptom. Individual Findings can be removed from the Findings view. Just back-swipe a listed finding and then tap the Delete button that subsequently appears on the right side of the table's cell. All Findings can also be removed from the findings list by tapping the navigation bar Clear button (or the Waste basket icon in the Android version of the app.) Please be aware that doing so also clears the differential diagnoses list of possible diagnoses and all of the checkmarked findings elsewhere. It removes the weighting of all findings that are checkmarked during the workup.
The application does not save the workup when it is cleared. There is no way to save findings with personally identifiable information in this version of STATworkUP. That feature is being considered for future updates. When you quit the application without clearing findings, they are saved for the next session. Upon startup an alert asks whether to continue the prior workup in progress or to delete it.
(Read more about how all this works in the help sections named Deriving Diagnoses and Calculations.)
Deriving Diagnoses ...
STATworkUP is intended to augment, but not to replace the traditional diagnostic process.
As any clinician knows, making a correct diagnosis is as much an art as a science. Most problems encountered in the real world are not "textbook cases" with only one diagnosis present and all its characteristic findings. Early in the course of an illness, only a few suggestive findings may be present and laboratory studies can be negative or equivocal. "Red herrings" are often present (findings that exist, but due to another unrelated disorder).
Although much effort has been spent by many programmers to come up with a "computerized diagnostician", only limited progress has been made. While computers are far faster and more accurate than people at numeric computation and searching of lengthy databases, people remain better at generalizing and inferring. No program yet written is capable of human insight and intuition. No practical method has been developed to categorize the myriad variations of symptoms - the smell of a septic wound, the briskness of an ankle jerk reflex, the pain that "started here and moved there and is somewhere between dull, aching, and throbbing."
No matter how accurate computer diagnostic programs become, we feel people will always be necessary to ask certain questions in just the right way, to examine the patient, and use clinical judgment to interpret the findings for a particular patient then recommend a treatment plan. People have limitations though. Organic memory can be less reliable than a hard disk, unfamiliar presentations of diseases can be overlooked, common diagnoses are unconsciously favored for uncommon ones and red herrings.
We have not attempted to have STATworkUP determine THE definitive diagnosis. In fact, this version does not even have all possible diagnoses defined, just a group of about 3,000 relatively common or important ones. The current version of STATworkUP does not take into account the intensity or temporal variations in symptoms, significant negative findings, or pathognomonic symptom groups. In fact, STATworkUP uses a relatively simple, but very thorough method to differentiate each of its included diagnoses.
Technically speaking, STATworkUP is somewhat heuristic in nature yet it incorporates Bayesian logic in its approach to determining diagnostic probability. A heuristic method is particularly useful to quickly arrive at a decision that is hoped to be close to the best possible answer, or "optimal problem solution". Heuristics are "rules of thumb", educated guesses, intuitive judgments or simply common sense. A heuristic approach is a general way or problem-solving, whereas, the Bayesian interpretation of probability is a more rigorous approach. It can be seen as an extension of logic that enables reasoning about uncertain statements.
To calculate the likelihood of a hypothesis, Bayesian logic specifies some prior probability, which is then updated in light of new relevant data. The Bayesian interpretation provides a standard set of procedures and formula to perform this calculation. The Bayesian approach interprets the concept of probability as "a measure of a state of knowledge", in contrast to interpreting it as a frequency or a physical property of a system.
STATworkUP provides groups of conditions that may be appropriate for further consideration when evaluating various possible diagnoses. It does not overlook the obvious diagnosis, doesn't forget to check unusual diagnoses, is not fooled by atypical presentations, and can even be helpful when more than one diagnosis coexists.
Considering the limitations mentioned above, inherent in computerized diagnosis, and in view of the main purpose of STATworkUP, we tried a number of possible approaches for generating a list of differential diagnoses. The method we are currently using has met our needs quite well, and has the advantage of being relatively straight-forward to implement (although not quite so easy to describe.)
In addition to the practical fact that it does generate reasonable differential diagnostic lists for selected findings, we feel that the method "makes sense" when compared with the way a human diagnostician arrives at a differential diagnosis list. Briefly, we first select a list of possible diagnoses based on how well the selected findings fit each diagnosis, then we also sort that list based upon how well each diagnosis accounts for some, or all, of its selected findings.
STATworkUP instantly compares the checked finding weights to the best weight for each diagnosis. Then it calculates a list of diagnoses for consideration. At a given likelihood meter setting the number of listed diagnoses often expands as additional findings are selected. The list is constrained when less findings are noted or when a group of checked findings are more specific for some diagnoses than others in the database. Additionally, the resulting differential diagnoses list can be prioritized.
When the prioritize switch is toggled ON the differential list is sorted by best fit. The resulting list is based upon the cumulative weights of all check marked findings in that case. It is also computed based upon the total number of selected findings that are associated attributes of each listed diagnosis. The differential diagnosis list is sorted by weighted match in the Prioritize mode. That is the product of weighted specificity times the finding inclusivity for each listed diagnosis at any given likelihood setting.
The list of possible diagnoses can be viewed anytime during the workup by simply tapping on the DIFFERENTIAL button. Use the sliding likelihood control meter in that view to show less likely, but possible diagnoses, based on findings. Raise the meter to more likely to reveal diagnoses that are more plausible based upon the checked finding selections. As that is done the list often becomes shorter, showing more likely diagnoses for consideration. Selecting alphabetize displays the differential diagnoses list alphabetically.
(The method of diagnoses computation is described in more detail in the Help section titled Calculations.)
Calculations ...
Whenever a finding is checked in STATworkUP, all diagnoses in the app are reevaluated for possible inclusion in the differential list. If all diagnoses had the same number of findings, and if each finding had equal weighting, then we could just sort the diagnoses by counting the numbers of selected findings that define each diagnosis. But, some findings are more diagnostically significant for conditions than other symptoms are (e.g., hemoptysis vs cough); and most diagnoses are defined by different numbers of findings as well.
STATworkUP rapidly computes a "Weighted Specificity" for each check marked finding. That factor is derived as a percentage of each finding's total usage in all of the diagnoses where it is connected. That is compared to its use for any given diagnosis to which it can portend some related attribution. (described in more detail below.) Diagnoses with "Weighted Specificity" that meets or exceeds the current setting of the Differential view LIKELIHOOD METER are included on the differential diagnosis list. The list is sorted based upon the "Weighted Match" of each diagnosis. This number is instantly calculated for each diagnosis from the product of its "Weighted Specificity" and "Finding Inclusivity" (also defined in detail below). A sorted list of most to least likely Diagnoses is shown in the Differential view with the PRIORITIZE setting selected. Otherwise the list is shown alphabetically.
Finding Weights...
STATworkUP describes each diagnosis or disorder in its database with useful sets of associated symptoms or conditions. It also includes reference information in drill-down texts or at attached web links. And the application correlates treatments or remedies, and useful studies or tests for each diagnosis.
When attempting to determine a diagnosis from a given group of findings, some findings are more useful than others:
A finding such as "FATIGUE" helps very little in weighting any specific diagnosis because fatigue occurs as a symptom for many of the diagnoses. A finding such as "HEMOPTYSIS" is more helpful, since it occurs with a lesser number of disorders, thus narrowing the diagnostic possibilities when it is present during workup (checked). A finding such as "BONE PROTRUSION THROUGH SKIN" is both necessary and sufficient to make the diagnosis of COMPOUND FRACTURE. The presence of other symptoms do not alter the certainty of that diagnosis, but might suggest other diagnoses that could also be present.
Findings, that may corroborate possible disorders, can be checked during problem assessment. STATworkUP instantly adds each finding's supportive weight as it is selected, to justify pertinent diagnoses placed on the differential list for consideration. The list can be sorted by most-to-least likely by turning on the prioritize switch.
The relative importance of a finding for any particular diagnosis depends, in large part, on the number of different diagnoses where it can occur. Uncommon findings usually have greater diagnostic specificity than do common ones. STATworkUP assigns a weight to each finding by simply determining the inverse of the number of diagnostic inclusions of that finding. In order to speed the numeric calculations an integer is applied rather than fractional numbers (this value is multiplied by a large constant).
Weighted Specificity...
Whenever the selected findings are changed (checking a symptom or condition on or off) STATworkUP recomputes the Weighted Specificity for each diagnosis in its data base. The Weighted Specificity is a number that indicates how well a given diagnosis can be "explained" by the selected findings. Irrelevant findings have no effect on this number.
STATworkUP first adds up the weights of all the POSSIBLE finding weights for each diagnosis to determine the "BEST FIT VALUE "for each diagnosis. Then it adds up the weights of all the checked conditions belonging to the finding set of each diagnosis to compute the "ACTUAL VALUE" for each diagnosis. Of course, if all the findings for a diagnosis are selected then the ACTUAL VALUE = BEST FIT VALUE.
By computing the ratio of ACTUAL FIT to BEST FIT for each diagnosis, STATworkUP generates a "Weighted Specificity" value for each diagnosis. If all the findings for a given diagnosis are present, then the weighted specificity for that diagnosis is 100%.
All diagnoses whose Weighted Specificity exceeds the sliding likelihood meter setting in the Differential view are listed and can be prioritized.
While Weighted Specificity is useful in building a list of likely diagnoses, it is sorted better by factoring in the influence of Finding Inclusivity as well as Weighted Specificity. STATworkUP also does this.
Finding Inclusivity...
Combining Finding Inclusivity with Weighted Specificity creates quite reasonable likelihoods for resulting differential diagnoses lists. The Finding Inclusivity for a diagnosis is a measure of how well the diagnosis accounts for the list of its selected findings. This is determined for each diagnosis by simply counting the number of selected conditions that are in the list of findings that describe the diagnosis. A Weighted Match for each listed diagnosis is computed by multiplying its Weighted Specificity by its Finding Inclusivity.
This STATworkUP sorting methodology nicely arranges the Differential of possible Diagnoses for selected findings.
Adjusting Possibilities ...
Each symptom or sign in STATworkUP, when selected as a finding, conveys some factored weight for each diagnosis that it defines in the database. The aggregated sum of all finding weights for each diagnosis establishes the 'BEST FIT VALUE' for that particular diagnosis. If all of the findings for a diagnosis are selected then that constitutes its best weighting. So it is quite likely to show up on the differential diagnoses list in that case. The combined weights of all selected findings determines the 'ACTUAL VALUE' for each diagnosis in the database. When only some of the diagnostic findings are check marked, the ratio of ACTUAL VALUE to BEST VALUE is called the Weighted Specificity for each diagnosis in the database.
This application allows you to input finding selections to see their associated diagnoses. And you can review other correlated symptoms or signs, tests, or remedies for them too. Then you can review other associated conditions, tests, or remedies for them. The Differential view contains a sliding control meter that lets you adjust how well computed diagnoses fit with the check marked findings. You can set the amount of likelihood that you want by adjusting the sliding control meter present in that view. At less likely settings the list of possible diagnoses is expanded, but the resulting array of diagnoses only loosely fits with the group of check marked findings. At more likely settings the differential list of conditions is constrained and the resulting list of diagnoses fits better with finding selections. Various settings can be useful during workup evaluation.
When starting a new assessment the default setting for the Differential sliding likelihood control meter is low. At that setting each diagnosis that is displayed on the Differential Diagnosis list is supported by at least a small amount of its total selected Findings' weight. In addition, the number of check marked Findings selected for each diagnosis are factored when computing the sort order of the listed Diagnoses in the Differential view. Diagnoses are listed from the top (most likely) to the bottom of the list (least likely) in the Prioritize mode.
Finding inclusiveness is used to determine the order in which diagnoses are displayed when the likelihood switch is set to Prioritize in the Differential view. That is, the count of findings selected for each diagnosis, chosen from the collection of its potential findings, is factored into the calculation that arranges how the diagnoses are listed in the Differential view. The product of the Weighted Specificity times the Finding Inclusivity is called the Weighted Match of each listed diagnosis in the view. The weighted match value determines the sort order of the listed diagnoses.
Prioritizing Differential ...
Differential Diagnoses for each symptom or sign, or for any listed check marked finding, can be shown by drilling down to their Info views and then selecting the CORRELATE menu item named DDX. Doing that builds a list of each symptom's correlated diagnoses in the app.
To see the list of possible Diagnoses that can be justified by the entire collection of check marked findings, just tap on the DIFFERENTIAL button. It appears next to the FINDINGS button in most views. Both buttons are present above the tab bar. The DIFFERENTIAL button is also present at the bottom of the Findings view. Selecting it builds a list of possible diagnoses for the findings that are check marked during the problem workup. The arrays of differential diagnoses are derived from all of the diagnoses in the database that fit with thier findings.
A sliding control meter is present in the Differential view. It can be adjusted to show the diagnoses for all of the selected findings at various likelihood settings. More likely settings better correlate diagnoses to a finding or the group of findings that are check marked during workup. By simply adjusting the sliding likelihood meter to lower or higher settings, the differential list of diagnosis can be expanded or constrained for any set of selected findings. Less likely diagnoses are shown at lower settings. They don't have much of their total best weight selected. At higher likelihood settings, a shorter list of diagnoses is built. Those have more of their combined findings' weight chosen, compared to the total Findings weight for other diagnosis in the database. To be listed in the Differential view a Diagnosis' weighted specificity must meet or exceed the likelihood meter setting. Weighted specificity is the cumulative weight of check marked findings for each diagnosis in the database compared to the best weight of all possible findings for each diagnosis.
The list of possible Differential Diagnoses can be prioritized or it can be alphabetized. If the differential switch is set to Prioritize then the table of possible Diagnoses that appears at the likelihood setting, are sorted by the amount of weighted-match of selected findings. If the switch is set to alphabetize then the Differential list is instead displayed alphabetically. The weighted match is the product of weighted specificity and the number of check marked findings selected from the array of findings that describe each diagnosis on the differential list. (See the Help section called Calculations that describes this in more detail.)
All of the selected findings can be viewed by tapping on the Findings button. adjacent to the Differential button, above the tab bar. In the Findings view all of the findings can be removed by tapping on the navigation bar Clear button. (Waste Basket icon in the Android version) Findings can also be removed individually by back-swiping cells on the Findings table and deleting them one-by-one from the Findings view. You can also uncheck them in other views by toggling their check marks off. When all of the findings are cleared the Differential list is also empty. No differential of possible diagnoses are generated when no findings have been selected.
