The Chief Complaint vs DiagnosUs
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
The Chief Complaint
This emergency medicine guide offers an algorithmic approach to over 50 common complaints. It provides decision support, links to medical resources, and includes a drug guide and calculators. A clinical community forum is also available for collaboration.
- Algorithmic approach to common ER complaints
- Clinical decision support algorithms
- Links to medical resources (PubMed, EM:RAP, etc.)
- Emergency medicine drug guide
- Medical calculators and scores
- ESCAVO Clinical Community forum
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The Chief Complaint app now includes access the new ESCAVO Clinical Community, a forum where clinicians can exchange ideas, ask questions and collaborate on sepsis and other clinical topics. How would you like to walk into the ER confident that you knew what to do, no matter what comes through the door? The Chief Complaint app uses an algorithmic approach to over 50 of the most common complaints encountered in emergency medicine. Never feel lost or overwhelmed again, not knowing what the next step in the work-up is. Not sure what tests to order or if the patient can go home? The Chief Complaint helps you answer all those questions and more! - Algorithm based approach to the most common emergency medicine complaints - Based on the #1 bestselling emergency medicine clinical guide "The Chief Complaint" - Used by the residents of LA County + USC emergency medicine program, one of the top emergency medicine programs in the world - Color coded by organ system for easy navigation - Exhaustively referenced to the most important studies and articles in emergency medicine (over 400 citations!) with direct links to PubMed abstracts for easy access to original sources - Over 60 high resolution clinical management and decision support algorithms - Direct subject-specific links to EM:RAP, Essentials of Emergency Medicine and theNNT.com for further resources and deeper dives on all subjects - Journal club feature allows you to dive deeper into the evidence basis of your decisions - Peer reviewed by leading physicians in emergency medicine - Important medical calculators and scores commonly used in the ER - Emergency medicine drug guide easily accessible right from the content pages - All content, including treatment algorithms, is built-in, network access is only required for content updates - Automatic content updating keeps app's contents constantly up to date free of charge The Chief Complaint is an invaluable resource for doctors, residents, medical students, nurses and other healthcare professionals working in emergency medicine and other acute care settings. Please send your feedback, questions or bug reports to info@escavo.com, we'd love to hear from you! Reviews: "The Chief Complaint is simply indispensable, carry it with me every shift. Excellent algorithms, concise, practical, clinically relevant explanations citing the current best-evidence for management decisions; without doubt Chief Complaint it is THE pocket Emergency Medicine reference to have with you at the bedside." -Manuel Montano, MD, PGY-3, LAC+USC EM Residency "...is really top notch. I really like how it organizes complaints in a flow pattern type way. This has allowed me to quickly adjust my decision making and makes it actually useful when I feel super pressured at work. The further detail located later has been helpful to one, get some good initial learning in and two, look to the resources cited for more in depth discussion." -David Benaron, UCSD Resident "Chief complaint is AWESOME...I think every single intern in the country should have one of these...SO COOL!" -James Grieme, UCSD Resident "The aptly named Chief Complaint is simply excellent. I really like the way it is laid out by cc and it's concise enough to be useful on a regular basis. I take it with me to every shift and would highly recommend it to anyone looking for a streamlined, functional, real-time guide for working up patients in the ED" -Nick Aldridge, UCSD Resident "... really something totally new in the medical education world. This app does something many have tried to do but few have achieved, which is to create an orienteering guide to the med-ed landscape while launching your thought processes AT THE BEDSIDE when confronted with a new undifferentiated and undiagnosed patient." -William "Billy" Mallon MD, Foreword
DiagnosUs
Engage with real medical cases to enhance your diagnostic skills and earn rewards. This educational game is designed for students and professionals to test their knowledge across various specialties and contribute to AI research.
- Analyze diverse medical cases
- Improve diagnostic skills
- Earn rewards for participation
- Contribute to AI research
- Study for medical exams
- Regularly updated datasets
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DiagnosUs is an educational game for medical students, doctors, premed students, other healthcare professionals, and citizen scientists to analyze medical cases, improve their skills, and earn prizes! Participation is open to anyone, regardless of educational background. Players compete against their peers to hone their skills by analyzing cases in our datasets. At the same time, they contribute their knowledge to help advance artificial intelligence research. DiagnosUs is a wonderful supplement for classes, clerkships, and in preparation for exams such as the USMLE® Step 1 & 2 Clinical Knowledge (CK), NBME® exams, MBBS, NCLEX® exams, COMLEX Level 1 & 2, MCAT®, NEET-PG, and many more! The app promotes an engaging, dynamic platform to test anyone’s medical knowledge while simultaneously contributing to the development of crucial machine learning algorithms. Try a wide range of cases in subjects such as radiology, dermatology, USMLE® preparation, MCAT® preparation, NBME® preparation, NCLEX® preparation, ultrasound, neurology, cardiology, ophthalmology, emergency medicine, surgery, internal medicine, pediatrics, orthopedics, family medicine, gastroenterology, pathology, and pulmonology. Utilize the power of DiagnosUs to study interactively! New datasets are added regularly, so players can always keep learning! Learn medicine fast: see a wide range of cases! - Anatomy - Physiology - Auscultation to listen for pulmonary abnormalities - Dermatological images to identify melanoma, basal cell carcinoma, squamous cell carcinoma, psoriasis, dermatitis, and other skin conditions - EEG - EKG / ECG - USMLE® practice questions - MCAT® practice questions - NBME® practice questions - Chest X-rays to look for pneumonia and cancer - Musculoskeletal X-rays - Ultrasound identification problems - Fundus eye images - MRI - Whole Slide Pathology Imagery - Chest CT - Mammograms and much more! The rewards that participants can earn in the app are made possible by our research partners and customers, who are developing artificial intelligence related to image analysis. These research partners and customers subsidize our prizes because our app participants help analyze images from large datasets of our research partners and customers. After participants win rewards, they can tap on the Profile tab and tap on the icon in the top-left corner of the Profile screen. This screen then shows a log of all the participant's rewards, and they can withdraw their rewards to a payment account.
Screenshots
Verdict
The clearest difference is update cadence: DiagnosUs at fortnightly against The Chief Complaint's every 9 months. The Chief Complaint's advantage is monetization model (free vs free with in-app purchases) and review sentiment (88% vs 79%). On price, rating, ratings volume and ads there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
On the App Store both sit at effectively the same score — 4.8 for The Chief Complaint against 4.8 for DiagnosUs. Both are backed by a comparable volume of ratings — 649 and 1K respectively. Written reviews are what separate them: 88% of The Chief Complaint's written reviews are positive against 79% of DiagnosUs's.
The Chief Complaint ships an update every 9 months, DiagnosUs fortnightly. The most recent releases landed on July 17, 2026 and September 24, 2026 respectively.
| Parameter | The Chief Complaint | DiagnosUs |
|---|---|---|
| Price | Free | Free |
| Rating | 4.8 (649 ratings) | 4.8 (1K ratings) |
| Positive reviews | 88.0% of reviews — better | 79.4% of reviews |
| Number of ratings | 649 | 1K — better |
| Update frequency | Every 9 months | Fortnightly — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free — better | Free with in-app purchases |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 11.0 — better | 16.0 |
| Further details — not scored | ||
| Size | 157 MB | 42 MB |
| Age rating | 17+ | 17+ |
| Developer | Escavo, Inc | Centaur Labs |
Customer experience
The Chief Complaint
DiagnosUs
User reviews
The Chief Complaint
From 649 App Store ratingsWhat we love
- 👍 Intuitive and easy to use interface
- 🧠 Comprehensive differential diagnosis algorithms
- 📚 Excellent educational resource for medical students and residents
- 🎯 Clear, concise, and thorough clinical guidance
- 🔗 Evidence-based recommendations with step-by-step approach
Room to improve
- 📱 No iPad landscape mode support
- ⚠️ Potentially outdated information (per one user)
- 📖 Sparse coverage in some specialty areas (OB/GYN, toxicology)
DiagnosUs
From 1K App Store ratingsWhat we love
- 💰 Earn money while learning
- 🧠 Helpful for medical students and professionals
- 🤓 Interesting and educational content
- 👍 Fun and engaging app
- 🤝 Responsive and helpful support team
Room to improve
- 🐛 Bugs and technical issues (crashes, freezes, slow loading)
- ⏱️ Time-consuming to compete and earn rewards
- 🤖 Inconsistent or inaccurate AI-graded answers
- 🤑 Difficult to earn significant amounts of money
- 🔒 Withdrawal issues for some countries
Bugs and requests
The Chief Complaint
Reported bugs
1 issue- App crashes when deleting bookmarks
Requested features
3 requests- iPad landscape orientation support
- Additional drug information in complaint categories
- Expanded content for OB/GYN and toxicology sections
DiagnosUs
Reported bugs
4 issues- App crashes and freezes
- Inaccurate or inconsistent grading of answers
- Withdrawal and payment issues for some users
- Compatibility problems with certain devices and OS versions
Requested features
5 requests- More diverse medical topics and case studies
- Separate competitions for students vs. professionals
- Ability to discuss and provide feedback on cases
- Improved instructions and explanations
- Compatibility with older devices and iOS versions
In-app purchases
The Chief Complaint
No in-app purchases
DiagnosUs
No in-app purchases
Questions
Is The Chief Complaint free?
Is DiagnosUs free?
Which has better reviews, The Chief Complaint or DiagnosUs?
Do The Chief Complaint or DiagnosUs have ads?
Which is updated more often, The Chief Complaint or DiagnosUs?
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