ClinicalTrials.gg
RecruitingNCT07827924DEONCAI3-1Updated Oct 30, 2026

Designing a Large Language Model Architecture for Shared Decision Making and Informed Intentions

An interventional study of Agentic LLM Chatbot and Usual Care LLM Chatbot in Shared Decision Making, Health Literacy and Patient Participation, sponsored by Harding Center for Risk Literacy. Recruiting at 1 site in Germany. Open to female participants aged 40 Years to 70 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-10-30.

Sponsored by Harding Center for Risk Literacy · Not applicable, Interventional, and Health services research

Updated Oct 30, 2026Now RecruitingFirst site in Germany+5 moreGo to Updates ↓
Phase
Not applicable
Study type
Interventional
Enrollment
330
Allocation
Randomized
Ages
40 Years to 70 Years
Sex
Female
01

Study summary

This study investigates a novel, agentic Large Language Model (LLM) architecture designed to facilitate Shared Decision-Making (SDM) in healthcare. While patients increasingly use standard LLMs for health information, these models often struggle with multi-turn conversations and fail to adapt to varying reading levels, disadvantaging vulnerable groups. By utilizing an agentic state-machine, this project aims to overcome common LLM deficits-such as context loss and uncritical agreement-to ensure clinically accurate, participatory patient conversations. The study evaluates whether this architecture improves informed decision-making compared to standard LLMs, particularly for patients with low health literacy.

Read the detailed description

Background \& Current State of Research Shared Decision-Making is widely recognized as the gold standard of patient-centered care. However, its successful implementation in clinical practice is frequently hindered by systemic time and budget constraints. Consequently, patients are increasingly turning to Large Language Models to independently access health information and navigate their medical options.

The Problem: Limitations of Standard LLMs Recent studies indicate that using standard LLMs can digitally reproduce existing health inequalities and participation gaps. These models struggle to adapt to different reading levels without a significant loss in quality. While highly developed prompting techniques can enhance clinical accuracy, the results remain highly variable depending on the specific model and technique used.

A central deficit becomes apparent in multi-turn interactions, which are essential for a natural SDM workflow. In these prolonged conversations, standard LLMs tend to exhibit "context rot," leading to a sharp decline in accuracy as the dialogue progresses. This issue is further exacerbated by model sycophancy (an uncritical tendency to agree with the user) and completion eagerness (a tendency to prematurely conclude the conversation). Because current LLMs often fail to meet evidence-based reporting standards and lack systematic validation of user comprehension, the burden of fact-checking remains entirely on the user. This dynamic significantly disadvantages vulnerable groups, particularly those with lower health literacy.

Project Objectives and Research Questions

This project proposes a technical and clinical solution to these challenges through the following core research questions:

Technical-Conceptual Framework: How can we develop a transparent and replicable workflow that formalizes the SDM process through an agentic state-machine, thereby eliminating structural deficits of LLMs (e.g., context rot and sycophancy) in prolonged interactions?

Clinical Evaluation (Primary Objective): Does this newly developed agentic LLM architecture achieve higher scores in participatory conversation management and demonstrate a significantly greater objective increase in informed decision-making among users during multi-turn interactions, compared to a standard baseline LLM?

Health Equity (Secondary Objective): To what extent can this agentic LLM architecture guarantee effective participatory conversation management for vulnerable patient groups with low health literacy?

02

Conditions studied

  • Shared Decision Making
  • Health Literacy
  • Patient Participation
  • Artificial Intelligence

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Keywords

  • Large Language Models (LLM)
  • Generative AI
  • Shared Decision Making (SDM)
  • Informed Decision Making
  • Patient Participation
  • Artificial Intelligence
  • Conversational Agents
  • Agentic AI
03

In context

Patient Participation

409 studies on the registry are indexed under Patient Participation; 101 are open to participants now.

This study's planned enrollment of 330 is above the median of 128 across 322 interventional studies indexed under Patient Participation.

Browse Patient Participation studies →

Lead sponsor

Harding Center for Risk Literacy is the lead sponsor of 3 studies on the registry; 1 is open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

The criteria were revised on the registry on Oct 30, 2026. See what changed

Ages eligible
40 Years to 70 Years
Sexes eligible
Female
Accepts healthy volunteers
Yes

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Biological sex: Female.
  • Age: 40 to 70 years old.
  • Country of residence: United States (US) or United Kingdom (UK).
  • Language: Native English speaker (English as first language).
  • Registered and verified user on the academic research platform Prolific.
  • Able to read, understand, and provide digitally.

Exclusion criteria

Exclusion Criteria:

  • Individuals who do not meet the automated pre-screening criteria on the Prolific platform.
  • Inability to use or access a computer, smartphone, or internet browser required to complete the digital study.

Note: Quotas will be enforced during recruitment to ensure a 50/50 stratified split between participants with and without university entrance qualifications to guarantee variance in educational backgrounds. Once a quota is filled, further participants matching that educational profile will be excluded.

  • Addendum: Women with BC symptoms
Terms in these criteria, in plain language(1)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

05

Study design

Phase
Not applicable
Primary purpose
Health services research
Allocation
Randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
330 participants (estimated)

Study arms

  • Experimental
    Shared Decision Making Chatbot

    Participants will engage in a multi-turn, AI-assisted consultation about mammography screening. They will interact with a newly developed agentic Large Language Model architecture that uses an integrated state-machine designed to actively guide the Shared Decision-Making process, adapt to the user's reading level, and prevent context loss.

    Behavioral: Agentic LLM Chatbot

  • Active comparator
    Standard Chatbot

    Participants will engage in a conversation about mammography screening using a standard, usual care Large Language Model (Mistral Large). This model represents the current consumer standard for AI health queries and lacks the specialized agentic state-machine and SDM workflow guidance.

    Behavioral: Usual Care LLM Chatbot

  • Active comparator
    Information brochure

    Participants will receive and read the standard informational patient brochure on mammography screening published by the German Institute for Quality and Efficiency in Health Care (IQWiG). This represents the current standard of care for patient information.

    Behavioral: IQWiG Standard Brochure

Interventions

  • BehavioralAgentic LLM Chatbot

    An interactive AI chatbot built with an agentic state-machine architecture designed to systematically guide users through the Shared Decision-Making process regarding mammography screening, with built-in ethical guardrails to prevent hallucination and sycophancy.

  • BehavioralUsual Care LLM Chatbot

    An unmodified, standard generative Large Language Model chatbot acting as a baseline control, used by participants to discuss mammography screening.

  • BehavioralIQWiG Standard Brochure

    The standard digital informational brochure on mammography screening provided by the german Institute for Quality and Efficiency in Health Care (IQWiG), used as a usual care baseline for patient education.

06

What researchers measure

Primary outcomes

  1. Patient-Reported Quality of Shared Decision-Making

    Assessed using the 9-item Shared Decision Making Questionnaire (SDM-Q-9). This validated instrument measures the patient's perceived involvement in the medical decision-making process. The questionnaire consists of 9 items, each rated on a 6-point scale ranging from 0 ("completely disagree") to 5 ("completely agree"). The raw scores are summed and multiplied by 20/9 to yield a total score ranging from 0 to 100. Higher scores indicate a higher perceived quality and greater patient involvement in shared decision-making.

    Time frame: Day 1

Secondary outcomes

  1. Multidimensional Informed Decision-Making

    Based on Marteau's conceptualization of informed decision-making. An informed decision is achieved when a participant has sufficient objective knowledge about mammography screening and their behavioral intention (to screen or not to screen) is congruent with their personal attitudes toward the screening. This is calculated as a composite measure integrating an objective knowledge test, an attitude assessment, and a screening intention question. Higher objective knowledge scores and higher attitude-intention congruence indicate a better-informed decision.

    Time frame: Day 1

  2. Subjective Decisional Conflict

    Assessed using a standardized Decisional Conflict Scale. This measures the participant's perceived uncertainty in choosing a screening option, their clarity of personal values, and their feeling of being supported in decision-making. Scores are transformed to a 0 to 100 scale. Lower scores indicate less decisional conflict and greater decision certainty.

    Time frame: Day 1

  3. Medical Accuracy and Safety of Generated Information

    A quantitative and qualitative assessment of the medical accuracy of the AI-generated texts. This is operationalized by counting the frequency (number of occurrences) and categorizing the severity of deviations from established medical evidence (i.e., misinformation or "hallucinations"). These deviations are identified via an integrated ethics module and/or expert review. Lower frequencies and lower severity ratings indicate higher medical accuracy.

    Time frame: Day 1

07

Study locations

1 of 1 sites recruiting
  • Brandenburg Medical School Theodor Fontane
    Neuruppin, Germany
    Recruiting
    • Felix G Rebitschek · Contact+49331-977-0
    • Felix G Rebitschek · Principal investigator
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References and documents

Publications

  • Rebitschek FG, Carella A, Kohlrausch-Pazin S, Zitzmann M, Steckelberg A, Wilhelm C. Evaluating evidence-based health information from generative AI using a cross-sectional study with laypeople seeking screening information. NPJ Digit Med. 2025 Jun 9;8(1):343. doi: 10.1038/s41746-025-01752-6. PubMed 40490558 ↗
  • Mendel T, Singh N, Mann DM, Wiesenfeld B, Nov O. Laypeople's Use of and Attitudes Toward Large Language Models and Search Engines for Health Queries: Survey Study. J Med Internet Res. 2025 Feb 13;27:e64290. doi: 10.2196/64290. PubMed 39946180 ↗
  • Laban, P., Hayashi, H., Zhou, Y., & Neville, J. (2025). Llms get lost in multi-turn conversation. arXiv preprint arXiv:2505.06120.
  • Krenn C, Loder C, Berger N, Jeitler K, Semlitsch T, Siebenhofer A, Wilfling D. Automated Approaches of Text Simplification of Patient Education Materials: Scoping Review. J Med Internet Res. 2026 May 7;28:e88365. doi: 10.2196/88365. PubMed 42097602 ↗
  • Keij SM, Branda ME, Montori VM, Brito JP, Kunneman M, Pieterse AH. Patient Characteristics and the Extent to Which Clinicians Involve Patients in Decision Making: Secondary Analyses of Pooled Data. Med Decis Making. 2024 Apr;44(3):346-356. doi: 10.1177/0272989X241231721. Epub 2024 Mar 4. PubMed 38563311 ↗

Individual participant data

Plan to share: Yes — De-identified individual participant data (IPD) underlying the results reported in the published article, including survey data (SDM-Q-9, decisional conflict, knowledge scores) and anonymized dialog transcripts, will be shared.

Time frame: Data will become available immediately following publication of the primary results and will be accessible indefinitely.

Access criteria: Data will be made publicly available as supplement material on the publishers website to any researcher or individual for non-commercial research purposes.

09

Updates

1 registry update since Sep 25, 2026
Status
Not yet recruiting→Recruiting
changed Oct 30, 2026
Sites
1 site added — first site in Germany
Show site
  • Brandenburg Medical School Theodor Fontane · Neuruppin, Germany
Oct 30, 2026
Start date
Sep 15, 2026→Oct 23, 2026 (actual)
Oct 30, 2026
Primary completion
Sep 30, 2026→Oct 30, 2026
Oct 30, 2026
Study completion
Sep 30, 2026→Oct 31, 2026
Oct 30, 2026
Eligibility
1 exclusion criterion added, 1 removed
What changed in the criteria
Exclusion criteria
  • Removed-
  • AddedAddendum: Women with BC symptoms
Oct 30, 2026
Show all 1 update
  1. Oct 30, 2026
    Not yet recruiting→Recruiting
    1 site added — first site in Germany
    Show site
    • Brandenburg Medical School Theodor Fontane · Neuruppin, Germany
    Start date Sep 15, 2026→Oct 23, 2026 (now actual)
    Primary completion Sep 30, 2026→Oct 30, 2026
    Study completion Sep 30, 2026→Oct 31, 2026
    Eligibility 1 exclusion criterion added, 1 removed
    What changed in the criteria
    Exclusion criteria
    • Removed-
    • AddedAddendum: Women with BC symptoms
    + 1 other change: verification date

From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗

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Registry details

Key details

Study ID
NCT07827924
Lead sponsor
Harding Center for Risk Literacy
Responsible party
Felix G. Rebitschek (Head of Research and CEO, Harding Center for Risk Literacy) — Principal investigator
First posted
Sep 18, 2026
Start date
Oct 23, 2026
Primary completion
Oct 30, 2026 (estimated)
Completion
Oct 31, 2026 (estimated)
Last update
Oct 30, 2026

Study contacts

Felix G Rebitschek, PhD
Contact
felix.rebitschek@fgw-brandenburg.de
+493319772162
Martin Lipsdorf
Contact
martin.lipsdorf@mhb-fontane.de
Felix G Rebitschek, PhD
principal investigator · Harding Center for Risk Literacy

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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