by: Surinder Yadav MD

The Med Student’s Differentials Dx app is designed for students that may have trouble remembering differentials for any particular symptom or sign. It is available for the iPhone and iPad.

The goal of the app is to reduce the incidence of diagnostic errors by providing information that is useful to understanding differentials in a concise package.

The home screen has two headings –Common Complaints and Serious Complaints.

If you choose to look at common complaints, the app provides a list of common symptoms and signs that a patient may complain of such as abdominal pain. Tapping on that button provides an alphabetical laundry list of serious causes and less serious causes but no clear delineation with respect to frequency of occurrence.

One thing I would like to point out, is that the app developers should have created the  laundry list in the descending order of occurrences. This would have been a simple addition that would increase the utility of the app. It would also have been relatively important to specify what is as rare as “Hens Teeth” or the most common etiology.

Once in a specific list, you have to click on questions to have some common question based answers as your reference for the possible problem and its related causes. The answers are very basic and direct instructions, such as – “If the pain is right lower side: consider appendicitis and call a surgeon or send the child to the ER”.

Clicking on the disease listed in the differential does not do anything and provides no reference material or information about the disease itself.

The app is limited in what it can provide but may be useful as a quick reference or reminder. For the layman who might want to have this type of information at hand, it could turn out to be confusing and anxiety provoking.

One thing that does irritate me is the disregard for grammatically correct sentences scattered throughout the app. The idea of the app is a thoughtful one in terms of trying to reduce diagnostic errors, however, with the way it is set up currently, the app may lead to more confusion.

Price:

• Currently $1.99

Likes:

• Easy to use
• Quick reference

Dislikes:

• Limited in reference material
• Basic information

Conclusion:

• The app is a quick and dirty reference material for those that may just be starting out in their careers or have trouble remembering lists.

iTunes Link

By: Brian Wells, MSM, MPH

“Differential Diagnosis i-Pocket” is another variant on the differential diagnosis theme for apps. This application contains a list of hundreds of symptoms, diseases, and findings that help formulate a differential diagnosis.

On the surface, such an application would be a virtual treasure trove of information for a clinician, especially when packed into an easy-to-use mobile application. Of course, the real key is in the implementation.

Differential Diagnosis i-Pocket is described in iTunes:

• The Differential Diagnosis pocket is a compact reference work that provides the basic foundation for formulating a thorough list of differential diagnosis.
• Completely updated 2nd edition
• Contains over 800 lists of symptoms, physical signs and abnormal findings (including laboratory tests)
• Keywords listed in alphabetical order for easy access
• An invaluable resource for medical students entering the clinical years and a great reference source for residents and other medical professionals
• For students, residents, nurses and all other healthcare professionals.

The application is displayed in a simple style with most of the actions happening through the tab bar at the bottom of the app. Here, the user can access the home, the table of contents, search functions and links to the developer’s other products.

Differential diagnoses, the application’s key point, are arranged in simple lists based off the user’s selection, whether from the table of contents or from search.

Beyond just a list of differential diagnoses, information on the disease is often provided as is etiology. For example, a search of Addison’s Disease returns information on adrenal cortical insufficiency as well as etiologies for primary and secondary causes.

Occasionally, one of the differential diagnoses will be highlighted in blue indicating a link. For example, acute abdominal pain in women gives pelvic inflammatory disease as a linked differential. When this occurs, the user can tap the link and be presented with additional information on that differential.

Strengths:

• The application is very easy to use and understand.
• The lists are laid out alphabetically and are searchable.
• Bi-directional arrows are provided for navigation between topic headings and subtopics.
• The differential diagnoses are typically extensive for each topic but are likely not complete for all topics.

Weaknesses:

• Each time I use this app, I can’t help but feel that it is incomplete.
• Firstly, it would be nice to organize the list by symptoms and disease, but this is a minor problem thanks to the search feature.
• However, one feature that I think would make this app immensely more powerful would be the ability to select differentials from the list and drilldown on those.
• Perhaps even another screen could be added with brief information on the differential and a way to differentiate among differentials.

For example, if I were to pick breast mass, differentials could be displayed in terms of common, such as fibroadenoma or breast abscess, and uncommon, such as Phylloides tumor. Selected differentials could then be chosen with information such as history, exam findings and treatment displayed for full comparison. This would make the app feel much more complete and be much more powerful.

Overall:

• Overall, this application does what it advertises it can do.
• It provides a differential diagnosis based on the user input. However, as previously stated, it does so in a way that makes the application feel incomplete.
• For the application’s price of $9.99, I would expect at least hyperlinks to informational websites per disease or even a link to that disease’s differential diagnosis for all differentials. Neither of those features is found fully implemented in this application.
• While this program will no doubt find use for those wanting a quick informational display, other users may find the program’s shortcomings frustrating in day-to-day use.

YouTube video review of the application:

iTunes Link: http://itunes.apple.com/us/app/differential-diagnosis-i-pocket/id345274160?mt=8#

Price: $9.99

Diagnosaurus is an app that you might be familiar with if your hospital / medical school uses Access Medicine. It’s on the homepage the Access Medicine portal.

Diagnosaurus helps you form a differential diagnosis (it helps you come up with a list of possible diseases or causes based on vague to specific symptoms). This is key to note, because I found many people reviewing this app in the app store complaining that it doesn’t help you make a diagnosis. That is not the purpose of this app. It only helps you “start” the process of formulating a differential.  In this review we’ll discuss how to use this application.

Advantages:

• Great for formulating differentials based on patients symptoms.
• Search toolbar, which allows you to quickly search thousands of symptoms.
• Loads in under 2 seconds, and does not require Internet connection. (Helpful when in parts of the hospital without wifi or reception)
• Stable, have been using it since March without any issues.
• Relatively cheap (99 cents)
• New version has landscape mode
• Hyperlinks within the app allow you to narrow down vague symptoms.
• Compatible with iPhone and itouch

Improvements that could be made:

• Saving recent page. If you were looking up a differential and then close the app, when you return it starts you on the home page. It would be nice if it started you off on the last page you were viewing.
• Have a search bar on the home page. I use the search bar almost 99% of the time, and I have to go through one of the categories to use it. Not a big issue but would save one step.
• No registration. App asks for your name and email address to “register you” for tech support when you first install it. I put in random info, and don’t really see the point of the registration process.
• Differentials can be a bit too broad at times, but this depends on your medical experience.

Who this App would be great for:

• Intern / nurse / medical student / PA student
• This app is particularly useful if you’re on your Internal Medicine rotation or Peds rotation. Its great for coming up with a quick differential before you present your patients in the morning.

Conclusion:

Overall, I’d definitely have to recommend this app to the above people. I’ve found it extremely useful in the wards, especially when I was on my internal medicine rotation. Even a seasoned attending might find this app useful for patients with atypical presentations. I’m honestly surprised this app is only rated 3/5 in the App store, but when I was reading the comments I saw alot of them were from people who were expecting an app for diagnosing, rather than for formulating a differential. For 99 cents its a great deal, and I don’t think you can go wrong with it.

[itunes]

[website]

Further Review:

I found the Access Medicine online version of Diagnosaurus helpful, but tedious to use, since there was no search function, and everything was more or less organized alphabetically. I’m glad they didn’t use the same approach when they converted this app for the iphone / itouch.

Gone are the alphabetical listings of symptoms, instead, replaced by a nice search toolbar that makes the process much quicker. The interface is simple and easy to use, although I don’t know the effectiveness of the different categories. Rarely, when I’m on the wards, do I find myself looking up particular diseases or organ systems. Those categories having huge listings within themselves, and are not very useful. The main utility in this App, and where it absolutely shines is in the symptoms category, and then using the search option from there. It does an excellent excellent job of giving a broad differential to work from. Some might argue the differential lists given can be too broad, this is true, and I feel this complaint is more of an issue of who is using this app and for what purpose. For a seasoned attending, the differential might be too much, but for an intern or med student, it might be perfect.

The other nice feature about this app is how it helps you narrow down your symptom. Lets say you want to look up the differential diagnosis for abdominal pain. When you do this, it gives you hyperlinks within the app that will narrow down your differential, such as, right upper quadrant abdominal pain verse left lower quadrant pain, and many others.

There is also a favorites bar. I didn’t use this option a great deal, but I could see how it might be useful to store some of the most popular symptoms and the differentials for them. Some of those being, abdominal pain, chest pain, headache, etc. (the pictures within this post are the ones provided in the app preview in the app store).