SO Second Opinion — Module 3

AI in Daily Medical Practice — Module 3 of 6

AI-Supported Clinical Decision Making

Handout — self-paced study material

~140–155 minreading + exercise time
Self-pacedplus a live case workshop and roleplay session
6 sectionsincl. 1 case exercise + 1 script worksheet
NextPost-Test after this handout

How this module works. Take the short Preview Quiz first — five minutes, ungraded. Then work through this handout (or the companion slide deck) at your own pace. Section D is a worked case exercise — form your own differential before you look at the AI output, don't skip ahead. Sections D and F are also run live as a case workshop and a roleplay session with your cohort; the handout gives you the individual groundwork for both. Finish with the Post-Test.

By the end of this module you will be able to:

Section A — AI as a Second Opinion, Not a Verdict (KNOW)

Module 2 dealt with a comparatively low-stakes use case: a documentation error is usually easy to catch and correct. This module is different. Diagnostic and decision-support AI touches the actual clinical reasoning that determines what happens to a patient, and that raises the stakes considerably. The single idea this whole module is built around is simple to state and hard to hold onto under time pressure: an AI decision-support tool is one voice in the room, not the person making the decision.

That distinction matters because these tools are explicitly designed to sound like an answer. A ranked differential, a highlighted region on a chest X-ray, a risk score with a decimal point — all of it is presented with a confidence and specificity that can feel more authoritative than a colleague's verbal opinion. It isn't. It's a statistical pattern match against the data the tool was trained on, produced by the same underlying technology — and subject to the same failure modes — you met in Module 1: hallucination, overconfidence, and bias toward whatever population the training data actually represented.

Three practical consequences follow directly from treating AI output as a second opinion rather than a verdict:

Watch for this Module 1 already flagged the moment of highest risk: when an AI's output happens to match what you already suspected. Scrutiny drops exactly when it matters most. That trap doesn't go away in this module — it gets sharper, because the stakes are higher. Module 4 builds a full, structured routine for catching it; for now, the working rule is: the more the AI's answer agrees with your gut, the more deliberately you should ask what would prove it wrong.

Section B — Differential-Diagnosis Support Tools: Capabilities and Limits (KNOW)

Differential-diagnosis support tools take a structured or free-text description of a patient's presentation — symptoms, history, sometimes vitals or basic labs — and return a ranked list of possible diagnoses, often with a probability-like score attached. Some are built into an EHR or a standalone app; increasingly, general-purpose AI chat tools are used the same way even when they weren't specifically built or validated for it.

What these tools are genuinely useful forWhat they are not built to do
Widening a differential you've already started — surfacing a possibility you hadn't weighted highly enoughReplacing history-taking and physical examination with a text description
A fast second pass when a presentation is unfamiliar or atypical for your own experienceAccounting for findings, context, or patient history that were never entered into it
Structuring your own reasoning — forcing an explicit, ranked list rather than an intuitive gut callKnowing what's common in your specific setting unless that was part of its training or validation data
A teaching aid for less experienced colleagues, when reviewed together rather than accepted aloneWeighing a rare-but-dangerous diagnosis appropriately if it was rare in the tool's training data too

Two limits deserve special attention because they fail silently — nothing about the tool's output signals that they've happened:

Section C — Multimodal Interpretation: Imaging, Labs, and ECG-Assisted Reads (KNOW)

Multimodal simply means a tool that works across more than one type of input — an image plus text, or a waveform plus a clinical note — rather than text alone. In clinical decision support this mostly shows up in three forms:

Imaging triage and computer-aided detection

Software that scans an image — most relevantly for this setting, a chest X-ray — and flags regions or findings that warrant closer review. This is not a niche research application: computer-aided detection for tuberculosis screening on chest X-ray is WHO-endorsed technology already in use across high-burden settings, and TB burden is directly relevant to clinical practice here. The tool's job is to flag and prioritize, not to issue a final radiological report.

ECG-assisted interpretation

Algorithms that read a 12-lead or single-lead ECG and suggest an interpretation or flag an abnormality — arrhythmia detection is the most mature version of this. Useful as a second read, particularly where same-day specialist ECG review isn't available; not a substitute for correlating the tracing with how the patient actually presents.

Lab pattern recognition

Tools that flag a pattern across a panel of results — a combination suggestive of a specific process — rather than a single out-of-range value. Useful for catching a pattern a busy clinician might not consciously assemble; still built on whatever combinations its training data emphasized.

The common thread across all three: a "triage" or "flagging" tool is built to raise sensitivity — catch more true positives — often at a real cost in false positives, and it is built to be reviewed by a clinician, not to stand alone as a report. Two failure modes are specific to this category and worth naming explicitly:

Failure modeWhat it looks like
Silent false negativeThe tool doesn't flag anything — and "nothing flagged" gets read as "nothing's there," when it may simply mean the finding fell outside what the tool was trained to detect.
Confident false positiveThe tool flags a region or pattern with a specific-looking confidence score, and that specificity gets mistaken for diagnostic certainty rather than a probability worth checking.
Practical habit Read an imaging or ECG flag the way you'd read a colleague's phone consult: useful, worth taking seriously, and still something you look at yourself before it changes management.

Section D — Case Workshop: Working a Case With and Without AI (THINK)

Do this in order Read the case. Write down your own differential — even just mentally, but better on paper — before you read the AI-generated differential below it. If you read ahead, the exercise loses most of its value; you can't un-anchor yourself once you've seen the AI's ranking.
Case — Step 1: the presentation A 34-year-old man presents to your clinic in Dili in early rainy season with four days of fever, frontal headache, diffuse myalgia, and mild retro-orbital pain. He reports wading through floodwater near his home three days before symptoms began. No rash yet. No cough, no dysuria, no diarrhea. Exam: temperature 38.7°C, mildly injected conjunctivae, no rash, no hepatosplenomegaly, no calf tenderness. A rapid malaria test is negative. A full blood count and platelet count are pending.

Before reading on — what's your own differential, and what would you order or watch for next?

Case — Step 2: AI-generated differential

You enter the same presentation into a general-purpose AI decision-support tool. It returns:

  1. Viral syndrome / influenza-like illness — most likely, self-limiting
  2. Infectious mononucleosis
  3. Early COVID-19
  4. Dengue fever — possible, recommend monitoring
  5. Bacterial pharyngitis

Leptospirosis does not appear on the list.

Now compare that ranking to your own. What's missing, and why might it be missing?

Discussion — what this case is built to show

  1. The AI's top-ranked answer reflects general global prevalence, not Dili in rainy season. "Viral syndrome, self-limiting" is a statistically reasonable top guess for a generic fever-and-myalgia presentation worldwide — and a genuinely risky one to act on here, this week, in this patient.
  2. Dengue is present but under-weighted, and leptospirosis is missing entirely — despite recent floodwater exposure being a textbook epidemiological clue for leptospirosis, and despite both conditions being locally endemic and clinically urgent. A tool trained mostly on data from settings where leptospirosis is rare will not reliably surface it, however good it is in general.
  3. A negative rapid malaria test narrowed one possibility but proved nothing about the others — a reminder that a single test result, like a single AI output, is one input, not a verdict.
  4. The clinically correct move here is to keep dengue and leptospirosis at or near the top of your own differential regardless of the AI's ranking, based on the exposure history and local epidemiology the tool never saw and wasn't weighted to prioritize — and to manage accordingly: monitoring for dengue warning signs, and a low threshold for empiric doxycycline if leptospirosis can't be excluded quickly, per local protocol.

If your own differential already had dengue and leptospirosis near the top, that's exactly the instinct this module is reinforcing. If it didn't, that's precisely why the habit in Section A — form your own impression first — matters more than any single case.

A habit you can actually use with any AI-generated differential

In the live workshop session, you'll work a second case in small groups, comparing your differentials before and after seeing AI input, and discussing where the group's collective judgment caught something the tool missed — or vice versa.

Section E — Validation Gaps: When the Tool Wasn't Built for Your Patients (FIND / THINK)

The case above is one concrete example of a general problem: every AI decision-support tool is only as good as the population it was trained and validated on, and almost none of the widely available tools were trained or validated on a Timor-Leste population specifically. That gap shows up in predictable, recurring ways:

None of this means these tools are useless in this setting — the imaging and documentation examples in Section C are genuinely valuable here too. It means trust has to be calibrated to fit, not assumed from the tool's general reputation or accuracy statistics published for a different population. A few practical questions help with that calibration:

1. Do you know, or can you find out, what population (geography, demographics, disease prevalence) this tool was trained or validated on?

2. For the specific clinical question you're using it for, is that training population close enough to your own patients that the output deserves high trust — or does it need to be treated as a rough prompt rather than a probability?

3. Are there diagnoses that are rare in the tool's likely training data but common or endemic where you practice? Which ones, specifically, do you need to keep actively in mind regardless of what the tool ranks?

4. If the tool is silent on a locally important possibility, would you notice the silence — or would "nothing flagged" quietly read as reassurance?

Section F — Talking to Patients About AI-Assisted Findings (THINK)

Module 1 covered the reverse situation: a patient arriving with their own AI-generated conclusion. This section covers the other direction — how you talk to a patient (or a colleague) when an AI tool contributed to your own findings or reasoning. The framing matters as much as the accuracy, because it shapes how much weight the patient puts on the finding and how much trust they place in you.

Two framing mistakes are common and both cause real harm. Overstating the tool's authority ("the computer found cancer") can cause disproportionate alarm before you've even finished your own assessment. Hiding that AI was involved at all, when a patient asks directly, damages trust once they find out — and in a small community, they usually do.

Disclosure — a screening tool flagged something on imaging

Say: "A screening tool flagged something on your X-ray that I want to look at more closely with you. It's a first pass, not a diagnosis — let me walk you through what I'm seeing and what we do next."
Avoid: "The computer says you have TB." (states a screening flag as a diagnosis, and hands your own clinical authority to the software)

When you disagree with the AI's output

Say: "A tool suggested [X], but based on your history and exam, I don't think that fits — here's what I think is actually going on and why."
Avoid: Quietly overriding the tool without mentioning it existed, if the patient later sees it referenced in their record — this reads as concealment even when the clinical judgment was correct.

A patient worried about being treated by "a machine"

Say: "I'm the one making the decision about your care. This tool is one more piece of information I use, the same way I'd use a colleague's opinion or a lab result — it doesn't replace my judgment or my exam of you."

Write your own version of one of these three scripts, in the language(s) you actually use with your patients, in your own words. You'll use it in the roleplay session with a colleague playing the patient.

Module Summary

LayerWhat this module put there
KNOWWhy AI decision support is a second opinion, not a verdict; what differential-support and multimodal (imaging, ECG, lab-pattern) tools genuinely do and don't do; the failure modes specific to this category, including silent false negatives.
THINKA trained habit of forming your own impression before or independent of the AI's — practiced directly on a locally-grounded case — plus a reusable checklist and disclosure language for talking to patients and colleagues about AI-assisted findings.
FINDHow to calibrate trust in a specific tool by checking what population it was actually trained and validated on, and which locally-important diagnoses you need to keep actively in mind regardless of its ranking.
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