How to tell a patient about a diagnostic error

The patient returned to the clinic with the result of a test ordered by another service. The finding had been there since the first visit, three months earlier, and the team had attributed the symptoms to another cause. The resident who receives her notices what happened before she finishes speaking. The question he asks himself is the hardest of the day: what to say now?

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

Telling a patient about an error is a conversation almost no one trains for and almost every doctor will have. This guide shows what patients expect to hear, what holds doctors back, what studies found about institutional programs and about teaching the conversation, and a step-by-step script to train it in medical school and residency.

Key points

• Patients want to know about every error that caused harm: what happened, why, how the consequences will be handled and how to keep it from happening again.
• Patients also want emotional support and an apology, and doctors tend to choose their words so carefully that they stop saying there was an error.
• Almost all students and residents in a survey agreed that serious errors should be disclosed, but only a third had received training.
• Institutional communication and resolution programs were associated with neutral or positive results on lawsuits and compensation.
• Simulation with a standardized patient and video review increased residents' confidence for this conversation.

Why disclose the error

A matter of trust

Diagnostic error has a particularity: often the patient only finds out later, as in the opening scene. When the explanation comes from someone else or from a piece of paper, trust is lost twice, through the error and through the silence. An honest conversation is how to repair the second loss, even when the first has already happened.

Error as data, not as a secret

In the study, the error is learning material, as the guide to the error log shows. In practice, it is also information that belongs to the patient, because it changes what they understand about their own health and about the next decisions.

Close neighbors

Three topics in this series touch on this one. Breaking bad news, with the SPIKES protocol, has a similar structure. Judging the error after the outcome suffers from hindsight bias. And the distress of the professional involved, the so-called second victim, weighs on how he can conduct the conversation. Each has its own guide.

What patients and doctors say

What patients want

In a study with 13 focus groups, bringing together 52 patients and 46 doctors, patients said they wanted disclosure of every error that caused harm (Gallagher et al., 2003). They sought four pieces of information: what happened, why it happened, how the consequences would be handled and how repetition would be prevented (Gallagher et al., 2003).

Patients also wanted emotional support from doctors after the error, including an apology (Gallagher et al., 2003).

What doctors do

Doctors in the same groups agreed that errors with harm should be disclosed, but said they "choose their words carefully" (Gallagher et al., 2003). In practice, they described the adverse event and avoided saying there was an error, why it happened and how it would be prevented; they feared an apology would create legal liability and did not know where to seek emotional support (Gallagher et al., 2003).

The gap between what the patient wants and what the doctor says is the heart of the problem. The good intention is there; the form is missing.

What doctors in training think

In a survey of students, interns and residents at two American academic centers, 889 of the 1,138 invited responded, or 78% (White et al., 2008). Almost all, 99%, agreed that serious errors should be disclosed to patients, but 87% recognized at least one barrier, such as thinking the patient would not understand (59%), would not want to know (42%) or might sue (33%) (White et al., 2008).

Only 33% had received training on communicating errors, and 92% expressed interest in such training (White et al., 2008). Among residents, 45% reported involvement in a serious error and 34% had already communicated a serious error (White et al., 2008).

What institutional programs show

The Michigan experience

The University of Michigan health system implemented an error disclosure program with an offer of compensation and compared the periods before and after (Kachalia et al., 2010). The monthly rate of new claims fell from 7.03 to 4.52 per 100,000 visits, and the rate of lawsuits fell from 2.13 to 0.75 per 100,000 (Kachalia et al., 2010).

The authors themselves note that the design cannot prove causation, that claims fell across the entire state in the same period and that the Michigan model has particular features (Kachalia et al., 2010).

In other hospitals

In a study at four Massachusetts hospitals, the implementation of communication and resolution programs was associated with better trends in the rate of new claims at some of them, and no hospital got worse after implementation (Kachalia et al., 2018). The authors concluded that transparency, apology and proactive compensation can be adopted without adverse financial consequences (Kachalia et al., 2018).

What remains to be learned

A 2026 rapid review retrieved 2,801 citations and included nine primary studies on these programs (Sokol-Hessner et al., 2026). The evidence supports positive or neutral effects on claims and legal expenses, with low strength of evidence, but it is scarce on the experience of patients, families and professionals, on patient safety and on communication (Sokol-Hessner et al., 2026).

For the student, the message is twofold: fear of litigation is the most cited barrier, and the available data contradict the idea that frankness increases legal risk. Legal and ethical rules vary by country, and guidance from the service and the professional council always comes first.

A script for the conversation

The four requests of patients in the 2003 study (Gallagher et al., 2003), together with emotional support, form a natural script:

1. Prepare yourself: confirm the facts, agree with the team on who speaks and set aside time and a private place.
2. Say that there was an error: in plain language, without euphemism. "The diagnosis we gave at the first consultation was wrong."
3. Explain what happened: the known facts, without speculating about what is still being investigated.
4. Explain why it happened, to the extent of what is known, and say that the analysis will continue.
5. Apologize: a sincere apology, without shifting blame to colleagues or to the system.
6. Say what will be done now about the consequences, and what the service will change to prevent a repeat.
7. Offer support and continuity: the name of the person following the case and how to get in touch.

Silence and emotion

After the word "error", the patient may cry, fall silent or become angry. Responding to the emotion before continuing with explanations is the same rule that applies to any difficult news. The patient's anger is understandable and is part of the conversation.

What to avoid

Avoid phrases that sound like a defense ("anyone would have thought the same"), excessive technical details and promises the service cannot keep. Also avoid blaming colleagues who are not in the room: the analysis of causes is collective and may still be ongoing.

How to teach error communication

What curricula do

A scoping review identified 21 studies describing 19 error communication curricula for physicians in training (Stroud et al., 2013). Most were a brief session, with a lecture or small-group discussion and role-play; 14 studies reported self-reported improvement in knowledge, skills and attitudes, and five used structured assessment and found improvement in skills (Stroud et al., 2013).

Attempts to measure behavior change in practice were limited, and the authors call for more rigorous evaluations and follow-up of retention (Stroud et al., 2013).

Simulation with a standardized patient

In a program with 55 first-year residents, each one disclosed an error to a standardized patient playing the role of a family member, twice, four weeks apart, and reviewed the video of the encounter alone or with a professor (Sukalich et al., 2014). Self-confidence rose significantly between sessions, with an effect size of 1.19, and external evaluators confirmed the improvement; video review with or without a professor gave similar results (Sukalich et al., 2014).

The topic already appears in undergraduate training

A survey of American medical schools had responses from 106 institutions, or 60%, and showed that error disclosure and apology are already taught, but without a consistent curriculum across schools (Wojcieszak, 2022).

A three-part activity

For a medical school or residency program, a format that fits into one afternoon:

• Before: a short reading on what patients expect and the seven-step script.
• During: simulation stations with an actor or a colleague, with an observer and the script grid. The clinical encounter simulation guide shows how to organize the stations.
• After: video review and structured feedback, as described in the feedback in clinical cases guide.

Use diagnostic errors in the scripts

Most simulation scripts use medication or procedure errors. Diagnostic errors have a different texture: the uncertainty was real, the decision seemed reasonable, and the outcome only became clear later. The guide on knowledge or clinical reasoning gap helps write the "why it happened" honestly, and the one on diagnostic uncertainty helps explain to the patient what was uncertain at the time.

The error as information in NEXO

NEXO starts from the idea that the error is information. With each guess in the case of the day, proximity in ICD-10 across five levels shows how far the hypothesis was, whether in the same chapter, the same group or the same category. The case arrives in up to six clues, and guessing close becomes the starting point for the next hypothesis.

The game handles diagnostic reasoning; the conversation with the patient is trained in simulation. The cases are fictional with a realistic clinical presentation, and the what NEXO is guide explains the whole match. How the modes are unlocked is on the NEXO economy page.

If you coordinate a medical school, a student league or a residency program and want to use cases as a starting point for communication activities, see NEXO Closer. Researchers in medical education can propose studies through NEXO Researcher. Physicians who review cases take part through NEXO Curator, and those who create health content on social media can take part through NEXO Creators.

Frequently asked questions

Should the physician tell the patient they made a mistake?

Patients say they want disclosure of all errors that caused harm (Gallagher et al., 2003), and nearly all physicians in training agree (White et al., 2008). Local rules and the service's guidance should also be followed.

What does the patient want to know after an error?

What happened, why, how the consequences will be handled and how repetition will be prevented, plus an apology.

Does apologizing increase the risk of a lawsuit?

Communication and resolution programs were associated with positive or neutral effects on complaints and legal costs (Sokol-Hessner et al., 2026), but the rules vary by country.

How can error communication be trained?

With simulation with a standardized patient and video review, which increased residents' self-confidence (Sukalich et al., 2014).

What is the difference from communicating bad news?

The structure is similar, but here the news includes the team's responsibility, which requires an apology and an explanation of the causes.

And the physician who made the error?

They suffer too, and this impact, called the second victim, is the subject of a separate guide in this series.

Error communication checklist

1. Confirm the facts and agree on who leads the conversation.
2. Set aside adequate time and place.
3. Say the word error without euphemism.
4. Explain what and why, as far as is known.
5. Apologize sincerely.
6. Say what changes now and in the service.
7. Offer continuity with a name and a contact.

Want to treat the error as information? Play the case of the day on NEXO.

References

1. Gallagher TH, Waterman AD, Ebers AG, Fraser VJ, Levinson W. Patients' and physicians' attitudes regarding the disclosure of medical errors. JAMA. 2003. https://pubmed.ncbi.nlm.nih.gov/12597752/
2. White AA, Gallagher TH, Krauss MJ, Garbutt J, Waterman AD, Dunagan WC, et al. The attitudes and experiences of trainees regarding disclosing medical errors to patients. Acad Med. 2008. https://pubmed.ncbi.nlm.nih.gov/18316869/
3. Kachalia A, Kaufman SR, Boothman R, Anderson S, Welch K, Saint S, et al. Liability claims and costs before and after implementation of a medical error disclosure program. Ann Intern Med. 2010. https://pubmed.ncbi.nlm.nih.gov/20713789/
4. Kachalia A, Sands K, Niel MV, Dodson S, Roche S, Novack V, et al. Effects Of A Communication-And-Resolution Program On Hospitals' Malpractice Claims And Costs. Health Aff (Millwood). 2018. https://pubmed.ncbi.nlm.nih.gov/30395501/
5. Sokol-Hessner L, Stewart CM, Sharma R, Zhang A, Gallagher TH, Kachalia A, et al. Programs for responding after patients are harmed by their healthcare: A Making Healthcare Safer IV rapid review. J Patient Saf Risk Manag. 2026. https://pubmed.ncbi.nlm.nih.gov/42369169/
6. Stroud L, Wong BM, Hollenberg E, Levinson W. Teaching medical error disclosure to physicians-in-training: a scoping review. Acad Med. 2013. https://pubmed.ncbi.nlm.nih.gov/23619064/
7. Sukalich S, Elliott JO, Ruffner G. Teaching medical error disclosure to residents using patient-centered simulation training. Acad Med. 2014. https://pubmed.ncbi.nlm.nih.gov/24280843/
8. Wojcieszak D. Measuring the Uptake of Disclosure and Apology Content in the American Medical School Curriculum. J Med Educ Curric Dev. 2022. https://pubmed.ncbi.nlm.nih.gov/35399788/