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Module 3 · Lesson 3.4
3.4
When AI is part of care, who answers for it, and what do patients deserve?

Responsibility & Patients

Who is responsible, fairness and bias, privacy, and how to talk with patients about AI

Overview

A tool can be accurate, tested and worth the money, and still raise hard questions. Who is at fault when it is wrong? Does it work equally well for every patient? Should patients be told it was used? This lesson covers the four questions you are most likely to meet. About 15-20 minutes.

By the end of this lesson you can:

Who is responsible?

Back to Mr. Diaz. Suppose the AI that drafts impressions had left out the nodule follow-up, the radiologist did not notice and signed the report, and the follow-up CT never happened. Who is responsible?

Today the short answer is: the clinician who signs. AI tools are treated as tools, and the radiologist who signs a report is responsible for everything in it, whoever drafted it. Others share responsibility for their own parts:

ClinicianChecks the AI output, uses their own judgment, and signs. Responsible for the final report or decision.
HospitalChooses the tool, tests it on its own patients, trains staff, and monitors it after go-live (Lesson 3.2).
DeveloperBuilds the tool, reports honestly how and on whom it was tested, and fixes known problems.
RegulatorIn the US, the FDA authorizes tools that diagnose or guide treatment and can require reporting of problems.

The law here is still developing, and it may change as AI tools do more on their own. For now, "the AI said so" is not a defense.

Fairness and bias

A model learns from its training data (Lesson 1.2). If some groups of patients are missing from that data, or if the data carry an unfairness from the past, the model learns that too. This is called algorithmic bias: a tool that works worse, or makes worse recommendations, for some groups of people.

Two real examples

A risk score that used cost as a stand-in for illness. A program used by US health systems to decide who got extra care predicted future health care costs. Because less money had historically been spent on Black patients with the same illnesses, the program rated Black patients as healthier than equally sick white patients, and fewer were offered extra care (Obermeyer et al., 2019).

Chest X-ray AI that missed more disease in some groups. Models trained on large chest X-ray datasets more often labeled sick patients as "no finding" if they were female, Black, Hispanic, younger, or on Medicaid insurance (Seyyed-Kalantari et al., 2021). Those patients would be the most likely to have a diagnosis delayed.

Questions to ask about any tool: Who was in the training data? Was performance reported separately for different groups, such as by sex, age and race? Has it been tested on patients like ours?

Privacy

AI is built from patient data, and using it often means sending data somewhere. A few basics:

Interactive: spot the PHI

A classmate is about to paste this into a free public chatbot. Click every piece of information that could identify Mr. Diaz. There are five.

Hi, I'm a medical student. Can you explain this CT report in simple words?

Patient: Miguel Diaz, DOB 02/19/1964, MRN 00482217.
CT angiogram of the chest, done 03/12/2026 at 01:40.

Findings: segmental pulmonary embolism in the right lower lobe. No CT evidence of right heart strain. 8 mm solid nodule in the right upper lobe. Recommend follow-up CT in 6-12 months.

His phone number is 555-0142 if the team needs to call him back.

The findings on their own are safe to ask about. Even so, the safer habit is to put the whole report into a tool your hospital has approved, because a rare finding plus a date can sometimes be enough to identify someone.

Talking with patients

Should patients be told when AI is used in their care? Views differ. Few patients are told about every piece of software involved in a scan. But most surveys find patients want to know when AI plays a real part in their diagnosis or in messages they receive, and they want a person to stay responsible. Some laws now require it: in California, since 2025, a message to a patient written by generative AI must say so, unless a licensed clinician has reviewed it.

Try it: answer Mr. Diaz

At his clinic visit, Mr. Diaz asks: "I read that computers read scans now. Did a computer read mine? Should I trust it?" Write two or three sentences you could say, then compare with a sample answer.

Name the issue

Interactive: which question does this raise?

Each situation mainly raises one of the four issues from this lesson. Pick the best fit.

A student pastes a discharge summary, with the patient's name, into a free chatbot to shorten it.
Protected health information has left the hospital in an unapproved tool.
A skin-cancer app was trained almost entirely on photos of light skin.
It will likely work worse for patients with darker skin, a fairness problem that starts in the training data.
A radiologist signs an AI-drafted report without reading it, and it contains an error.
The radiologist who signs is responsible for the whole report, whoever drafted it.
A portal message about test results was written by an AI, and the patient thinks their doctor wrote it.
The patient was not told AI was used. In some places, such as California, this now has to be disclosed unless a clinician reviewed it.
A tool's paper reports accuracy for all patients together, but not separately by sex, age or race.
Without results by group, nobody can tell whether the tool works worse for some patients.
A hospital switches on a triage tool and never checks how it performs after go-live.
The hospital is responsible for testing and monitoring the tools it chooses.

Knowledge check

Answer each question to continue. Any answer is fine; read the explanation.

An AI drafts a radiology impression with an error, and the radiologist signs it. Today, who is mainly responsible for the report?

The clinician who signs is responsible for the content, whoever drafted it. The hospital and developer have their own duties, but they do not replace the signer's.

Why did the health-care risk score in the Obermeyer study treat Black patients unfairly?

The target the model learned, cost, carried a past unfairness. Bias can enter through what a model is asked to predict, not only through who is in the data.

A patient asks if AI read their scan. Which reply is best?

Be honest, keep it simple, and make clear that a person is responsible. Dismissing the question or overstating the AI both damage trust.

Key takeaways

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