Clinical case simulators for residency: how to choose

Residency exams demand decisions, not just facts. You read a case, choose the next test, decide on the management and deal with what comes next. Clinical case simulators promise to train exactly that, with virtual patients who respond to your choices. A randomized trial with newly graduated doctors in an emergency department in Singapore found no major differences in learning outcomes between virtual patient simulation and in-person simulation for sepsis and trauma, although participants were more satisfied with the in-person one (Low et al., 2024).

NEXO is a daily medical diagnosis game: one clinical case a day, six progressive clues, and ICD-10 proximity feedback across five levels.

This guide presents some well-known clinical case simulation platforms, always based on what each one says on its own page, summarizes what the studies show and proposes criteria for you to choose the one that makes sense for your moment.

Main points

• Clinical case simulators put you in front of a virtual patient who responds to your questions, tests and management.
• The platforms vary in format: computer screen, cell phone, virtual reality and conversation with artificial intelligence.
• There are studies on specific platforms, but most are small, without a comparison group or based on satisfaction and confidence.
• The best simulator is the one that fits your goal, your language and your routine; no list replaces testing.
• Long simulation and short cases complement each other: one trains the whole appointment, the other trains reasoning in volume.

Summary

• What a clinical case simulator is
• Well-known platforms and what each one offers
• What the studies show
• How to choose a simulator for residency
• How to fit simulation into your study
• Frequently asked questions
• Checklist for choosing a simulator

What a clinical case simulator is

A clinical case simulator is a program in which you conduct the care of a virtual patient. You ask questions, examine, order tests, decide on management and see the patient get better or worse according to your choices. At the end, you receive feedback on what you did.

Virtual patient, simulation and game

The terms get mixed up. "Virtual patient" is the name most used in the literature for interactive computer cases, and the text about virtual patients explains the definitions and the general evidence about them. Simulation with mannequins and actors, done in a laboratory, is covered in the text about care simulation. Here the focus is on digital platforms that you can use alone or with your institution.

Most common formats

Format	How it works	What it trains best
Interactive case on screen	You choose questions, tests and management in menus or text fields	Sequence of care and choice of tests
Conversation with patient by AI	You ask in natural language and the patient responds	History taking and communication
Virtual reality	You enter an immersive environment with virtual reality goggles	Team care, emergency and prioritization
Short cases with clues	The data arrives little by little and you give the diagnosis	Diagnostic reasoning in volume

Table source: Editorial organization based on the descriptions of the platforms cited on this page and the text about clinical reasoning games.

Why it matters to those who are going to do residency

Residency exams usually bring cases with several stages: diagnosis, complementary test, management and complication. Simulators train this sequence in an environment where making a mistake harms no one. For the resident, simulation also helps practice rare or high-risk situations that do not always appear in the service.

Well-known platforms and what each one offers

NEXO, the diagnosis game of this blog, opens the list. The other platforms were chosen because they are internationally known and have an official page with clear information about the product, and they are in alphabetical order, not of quality. Their descriptions come from the official page of each one, accessed on October 11, 2026; features, languages and access conditions change over time, so check directly at the source before deciding.

NEXO

NEXO works with short cases: the clinical case arrives in clues, up to six, and you give your guess by the name of the diagnosis or by the ICD-10 code, with the proximity of each guess shown in five levels. The game runs on the site nexo.wiki.br and in the iPhone app and serves to keep diagnostic reasoning in volume between one long case and another. The modes and resources for studying are in "Treinar no NEXO", further below.

Aquifer

According to the official page, Aquifer is a virtual teaching solution that helps students master the basic knowledge and clinical reasoning needed for care and for high-stakes exams (Aquifer). The page states that the courses are created by a consortium of clinical educators and that the platform combines virtual patient encounters, course content and formative assessment (Aquifer). The stated focus is the medical student, with tools also for teachers and institutions.

Body Interact

The official page describes Body Interact as a virtual patient simulator for teaching and assessing clinical reasoning and decision-making (Body Interact). According to the site, the virtual patients range from 6 months to 99 years, respond dynamically to the student's decisions, and the scenarios bring detailed feedback and competency data on communication, assessment and management (Body Interact). The site lists versions for medicine, nursing, high school and pre-hospital care.

Full Code

According to the official page, Full Code is a simulator in which you treat simulated patients, with adjustable difficulty level from beginner to specialist (Full Code). The site mentions conversations with patients through artificial intelligence, an AI tutor, medical images, scoring and detailed feedback at the end of each case, and says the platform works on any device (Full Code). There are options for individual use and for educators and institutions.

i-Human Patients

The official page, hosted on the Kaplan domain, presents i-Human Patients as virtual patient simulation that helps students develop skills for clinical practice and for licensing and certification exams (i-Human Patients). The site highlights varied avatars, personalized feedback and analysis and reporting tools to track student progress (i-Human Patients). The stated focus is educational institutions.

Oxford Medical Simulation

According to the official page, Oxford Medical Simulation combines clinical simulations in virtual reality with artificial intelligence, data analysis and support for institutions (Oxford Medical Simulation). The site speaks of unlimited and psychologically safe practice in virtual reality, with evidence-based feedback, and lists solutions for medical schools, health systems and postgraduate medical education, which includes residency (Oxford Medical Simulation).

Quick comparison

Platform	Main format, according to the official page	Audience stated on the page
NEXO	Short cases in clues, with a guess by name or by ICD-10	Medical students, residents and physicians
Aquifer	Virtual patients with course content	Students, teachers and institutions
Body Interact	Virtual patients that react in real time	Medicine, nursing, high school and pre-hospital care
Full Code	Simulated cases with AI, on any device	Individuals, educators and institutions
i-Human Patients	Simulation with avatars and reports	Educational institutions
Oxford Medical Simulation	Virtual reality with AI	Schools, health systems and postgraduate education

Table source: NEXO row from the description of the game in this blog; other rows, official pages of Aquifer, Body Interact, Full Code, i-Human Patients and Oxford Medical Simulation, opened on 10/11/2026.

What this list does not say

After NEXO, the list follows alphabetical order because there is a lack of studies comparing all the platforms with each other. Prices and access conditions were left out because they change often and depend on each institution's contract. Finally, the pages of the other platforms are in English; before choosing, check whether the platform offers cases in Portuguese and whether the epidemiology and protocols match the Brazilian reality.

What the studies show

The general evidence on virtual patients is summarized in the text about virtual patients. Here it is worth looking at studies with digital simulation platforms, including some of those cited.

Virtual and in-person simulation

In the Singapore trial, 40 newly graduated doctors were randomly assigned to 70 minutes of virtual patient simulation or in-person simulation on sepsis and trauma (Low et al., 2024). Blinded evaluators found no significant difference in overall scores between the groups, and satisfaction was lower with virtual simulation (Low et al., 2024). The study is cited on the Full Code page itself, but the published abstract does not identify the platform used.

A study with Full Code

A retrospective study with 590 medical students from Peru used score data from the Full Code platform (Salafia and Perez-Ochoa, 2025). Course grades correlated with the platform score, and the authors concluded that use was feasible, but that prospective studies are needed to know whether the platform directly improves learning (Salafia and Perez-Ochoa, 2025).

A study with Oxford Medical Simulation

A pilot project developed with Oxford Medical Simulation created virtual reality scenarios about diabetes emergencies for non-specialist doctors in the United Kingdom (Mallik et al., 2022). Among the 39 participants who responded, average confidence in managing diabetic ketoacidosis went from 3.92 to 5.41 on an 8-point scale (Mallik et al., 2022). The study measured confidence and reported behavior change, not performance with patients.

Virtual patient with a reasoning script

In a multicenter study with 285 students, a class on the diagnostic approach to a symptom followed by practice with virtual patients improved final diagnosis accuracy compared with baseline, with an absolute gain of 27% in abdominal pain and 32% in loss of consciousness (Dekhtyar et al., 2021). Compared with the group trained on the other symptom, the 13% gain was not statistically significant (Dekhtyar et al., 2021).

How to read these studies

Question	What the studies above allow us to say
Does virtual simulation teach as much as in-person simulation?	In a small trial, results were similar, with lower satisfaction in the virtual one
Does a specific platform improve grades?	The correlation exists, but it does not prove that the platform caused the improvement
Does virtual reality increase confidence?	In a pilot, yes; performance with patients was not measured
Does a reasoning structure help?	A class with a script plus practice improved compared with baseline

Table source: Editorial synthesis based on Low et al., 2024, Salafia and Perez-Ochoa, 2025, Mallik et al., 2022 and Dekhtyar et al., 2021.

Reading them together is encouraging, but cautious. Digital simulation seems to work as well as other formats in some scenarios and combines well with a reasoning script. Large studies comparing platforms and measuring performance with patients are lacking.

How to choose a simulator for residency

With so many options, the best choice depends on what you want to train and how you study. The criteria below help you decide before investing time in a platform.

Practical criteria

Criterion	Question to ask	Why it matters
Goal	Do I want to train diagnosis, management, emergency or communication?	Each format trains one part of care better
Language	Are the cases in Portuguese?	Reading in another language adds effort and can change terms
Context	Do the epidemiology and protocols match Brazil?	Management varies between countries
Feedback	Does the simulator explain why the decision was right or wrong?	Feedback is what makes practice count as learning
Time per case	Does a case take minutes or an hour?	Long cases require study blocks; short ones fit into breaks
Device	Does it work on a phone, on a computer or does it require virtual reality glasses?	It defines where and when you will be able to use it
Access	Is it for individual use or does it depend on a college contract?	Several platforms cited state that they serve institutions

Table source: Editorial criteria based on the differences between the platforms described on the official pages cited and the findings of the studies on this page.

Ask your institution

Several platforms on this list state that they serve colleges and hospitals. Before looking on your own, ask your course coordination, the library or the residency program whether institutional access already exists. It is worth asking before looking on your own.

Test before deciding

Using it is the best test. Do two or three cases and observe: did the feedback help you understand the mistake? Do the cases look like the questions you will face? Could you fit the platform into your week? If the answer is no to all three questions, the platform may be great, but not for you right now.

An annotated session

To see how the criteria work in practice, imagine a one-hour session in a screen simulator, with a case of chest pain in the emergency department.

1. Before starting (5 minutes). You set the goal of the session: to train the sequence of tests in chest pain. You write down the three serious hypotheses you cannot miss.
2. During the case (30 minutes). You take the history, examine, order tests and decide on the management. At each decision, you write the reason in one line.
3. In the feedback (10 minutes). You compare your choices with the platform feedback and mark where you diverged.
4. After the case (15 minutes). You separate the mistakes into two groups: what you did not know and what you knew but did not apply. The first group becomes a study topic; the second becomes a reminder in your reasoning script.

The example shows that time in the simulator is only half of the training. The other half is preparing and reviewing. A platform with poor feedback makes this review difficult, and that is why feedback appears as a central criterion in the table.

Common mistakes when choosing

• Choosing by the visuals. Impressive graphics do not guarantee good feedback.
• Ignoring the language. Cases in English can be useful, but they take more time and use other protocols.
• Using only one format. Long simulation does not replace short cases, and the opposite is also true.
• Doing cases without reviewing. Without writing down the mistake, the next case repeats the same error.

How to fit simulation into study

Simulators work best when they have a defined place in the routine. A study week can combine different formats.

A weekly script

1. One or two long cases per week in a simulator, chosen by the topic you are studying.
2. Short cases every day to keep diagnostic reasoning in volume.
3. Exam questions to check whether the knowledge is solid.
4. Review of mistakes at the end of the week, separating lack of knowledge from reasoning failure.

The text on how to fit games into the study routine brings more organization ideas, and the error notebook helps organize mistakes into a review list.

For those already in residency

For the resident, the simulator has another role: training what the service does not offer often. Rare situations, high-risk emergencies and cases outside your base specialty are good candidates. The Oxford Medical Simulation page, for example, lists solutions aimed at graduate medical education (Oxford Medical Simulation), and the Body Interact page highlights feedback on communication, assessment and management (Body Interact).

A practical way to use it is in pairs or in a small group, with one colleague running the case and another observing and taking notes. Afterwards, the two discuss the decisions, just as is done in the debriefing of an in-person simulation. The text on care simulation explains how to conduct this conversation.

Use a reasoning script

Studying with virtual patients and a diagnostic script suggests that structure helps (Dekhtyar et al., 2021). Before each case, remember the path: summary of the problem, hypotheses in order, data that separates the hypotheses, test that answers the doubt and management. The text on differential diagnosis with clues details this script.

Training on NEXO

NEXO works like the short case format in the table: each case arrives in up to six clues, one at a time, and you give the guess by the diagnosis name or the ICD-10 code. At each wrong guess, the game shows the proximity in five levels, from different chapter to exact ICD, and opens the next clue. It is a way to keep diagnostic reasoning in volume on the days between the long simulator cases.

The Daily brings one case per day, the same for everyone, and the Archive gathers the previous daily cases. Multimedia brings images, audio and other exams, and Continents changes the background epidemiology. Adrenaline adds time, useful for training decision-making under pressure. How each mode is unlocked is on the NEXO Economy page.

Save, discuss and take it to your institution

The Anki button creates the card straight from NEXO and opens it in the Anki app. The Group tab of the ranking, which gathers invited colleagues, lets you study with your class or with your residency colleagues. If you coordinate a residency, a student league or a medical school and want to use short cases in teaching, check out NEXO Closer. Researchers who study simulation and clinical reasoning can propose studies through NEXO Researcher, and physicians who want to review cases in their specialty can take part through NEXO Curator. Those who produce medical content can check out NEXO Creators.

Frequently asked questions

What is the best clinical case simulator for residency?

It depends on what you want to train, the language and how you study. There are no studies comparing all platforms with each other, so this guide describes each one based on its official page and proposes criteria for choosing.

Do clinical case simulators work?

The studies are encouraging, but limited. In a randomized trial, simulation with a virtual patient and in-person simulation had similar results in sepsis and trauma (Low et al., 2024). In another study, practice with virtual patients combined with a reasoning script improved diagnostic accuracy compared with baseline (Dekhtyar et al., 2021).

Are the simulators in Portuguese?

NEXO has the game in Portuguese, English, Spanish, French, German and Russian. The official pages of the other platforms consulted for this guide are in English. Before choosing, check with the platform whether there are cases in Portuguese and whether the protocols match practice in Brazil.

Is virtual reality simulation worth it?

It can be worth it for training emergencies and teamwork. In a pilot project with virtual reality about diabetes emergencies, physicians' confidence increased, but the study did not measure performance with patients (Mallik et al., 2022).

Does a simulator replace exam questions?

They are different tools. Questions check knowledge; simulators train the sequence of care. Using both, with short cases in between, covers more parts of your preparation.

Is it worth using a simulator at the beginning of the course?

It can be worth it, as long as the case matches what you already know. Some platforms state that they adjust the difficulty, such as Full Code, which says it offers levels from beginner to specialist (Full Code). Cases that are too hard at the beginning tend to frustrate more than teach.

How does NEXO compare to a simulator?

NEXO is a short case format, with up to six clues and proximity of the guess in ICD-10, designed to train diagnostic reasoning every day. It complements full care simulators. To learn about the game, read what NEXO is.

Checklist for choosing a simulator

1. Define the goal: diagnosis, management, emergency or communication.
2. Check the language and whether the protocols match Brazil.
3. See what the feedback is like after each case.
4. Work out the time per case and where it fits in your week.
5. Check the device you need.
6. Ask your institution whether access already exists.
7. Try two or three cases before deciding.
8. Combine formats: long simulation, short cases and questions.
9. Use a reasoning script in each case.
10. Review your mistakes every week.

Want to keep your diagnostic reasoning sharp between one mock exam and the next? Play the case of the day on NEXO.

References

1. Low MJW, Chan GWH, Li Z, et al. Comparison of virtual and in-person simulations for sepsis and trauma resuscitation training in Singapore: a randomized controlled trial. J Educ Eval Health Prof. 2024. https://pubmed.ncbi.nlm.nih.gov/39552082/
2. Salafia MA, Perez-Ochoa ME. Game-based educational experience in clinical simulation and academic achievement in medical students: a retrospective study. BMC Med Educ. 2025. https://pubmed.ncbi.nlm.nih.gov/40181334/
3. Mallik R, Patel M, Atkinson B, Kar P. Exploring the Role of Virtual Reality to Support Clinical Diabetes Training: A Pilot Study. J Diabetes Sci Technol. 2022. https://pubmed.ncbi.nlm.nih.gov/34210183/
4. Dekhtyar M, Park YS, Kalinyak J, et al. Use of a structured approach and virtual simulation practice to improve diagnostic reasoning. Diagnosis (Berl). 2021. https://pubmed.ncbi.nlm.nih.gov/34246202/
5. Aquifer. Official page, accessed on 10/11/2026. https://www.aquifer.org/
6. Body Interact. Official page, accessed on 10/11/2026. https://bodyinteract.com/
7. Full Code Medical Simulation. Official page, accessed on 10/11/2026. https://www.fullcode.app/
8. i-Human Patients (Kaplan). Official page, accessed on 10/11/2026. https://www.i-human.com/
9. Oxford Medical Simulation. Official page, accessed on 10/11/2026. https://oxfordmedicalsimulation.com/