MedMemoryBench: Benchmarking Agent Memory in Personalized Healthcare

AuthorsYihao Wang, Haoran Xu, Renjie Gu et al.

arXiv 20262026

TL;DR

MedMemoryBench uses a streaming evaluate while constructing protocol with noise augmented trajectories to reveal memory saturation, where accuracy on IG drops from 43.60% to 25.60% under Mixed noise.

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THE PROBLEM

Memory saturation in medical agents: performance drops under noisy accumulation (IG 43.60% → 25.60%)

MedMemoryBench shows that when Mixed noise is injected, IG accuracy for Unstructured Long Context falls from 43.60% to 25.60%, and MCD from 24.50% to 10.25%.

In personalized healthcare, this memory saturation means agents mis handle safety critical personalization, degrading complex reasoning exactly when long term tracking is most needed.

HOW IT WORKS

MedMemoryBench — streaming evaluation with trap events and noise augmentation

MedMemoryBench centers on Patient Profile Construction, Disease Progression Event Generation, Multi turn Sessions Simulation, and Memory Extraction and Query Construction to create year long, clinically grounded trajectories.

You can think of MedMemoryBench like a hospital wide memory stress test, where patient histories accumulate like medical charts while noisy notes and family consultations clutter the file.

This design lets MedMemoryBench expose memory saturation and retrieval failures that a plain context window or static benchmark cannot, especially under streaming evaluate while constructing conditions.

DIAGRAM

Streaming evaluate while constructing protocol for MedMemoryBench

This diagram shows how MedMemoryBench feeds chronological sessions into memory methods and evaluates at streaming checkpoints without future leakage.

DIAGRAM

MedMemoryBench data construction and noise augmentation pipeline

This diagram shows how MedMemoryBench constructs patient trajectories, simulates sessions, extracts memories, and injects noise for Efficient and Mixed modes.

PROCESS

How MedMemoryBench Handles a Patient Trajectory and Streaming Evaluation

  1. 01

    Patient Profile Construction

    MedMemoryBench builds 20 chronic disease Patient Profile Construction cases from de identified real scenarios, expanding family background and lifestyle with LLM assistance.

  2. 02

    Disease Progression Event Generation

    MedMemoryBench performs Disease Progression Event Generation to create expert verified one year diagnostic reports and a temporal event graph with injected trap events.

  3. 03

    Multi turn Sessions Simulation

    MedMemoryBench runs Multi turn Sessions Simulation where patient and physician agents converse along the event graph, recording summaries as accumulated contextual memory.

  4. 04

    Memory Extraction and Query Construction

    MedMemoryBench applies Memory Extraction and Query Construction with Trap Agent, Query Agent, and Critique Agent, then evaluates memory methods using the streaming STREAMEVAL protocol.

KEY CONTRIBUTIONS

Key Contributions

  • 01

    MedMemoryBench benchmark for personalized healthcare

    MedMemoryBench introduces a four stage pipeline with Patient Profile Construction, Disease Progression Event Generation, Multi turn Sessions Simulation, and Memory Extraction and Query Construction, yielding about 2,000 sessions and 16,000 turns.

  • 02

    Streaming evaluate while constructing protocol

    MedMemoryBench defines STREAMEVAL with checkpoints every Δ=10 sessions, enforcing src(q) session ids ≤ t to avoid future leakage while assessing evolving memory states.

  • 03

    First study of memory saturation in healthcare agents

    MedMemoryBench adds Noise Augmentation with general health consultations and proxy family sessions, showing IG accuracy drops from 43.60% to 25.60% and MCD from 24.50% to 10.25% under Mixed noise.

RESULTS

By the Numbers

Avg. accuracy Efficient

51.21%

+9.63 over BM25 Efficient (41.58% vs 34.70%)

Avg. accuracy Mixed

41.55%

+12.69 over BM25 Mixed (41.55% vs 28.86%)

IG Efficient Letta

52.87%

+31.71 over BM25 Efficient IG (52.87% vs 21.16%)

MCD Efficient A Mem

31.93%

+13.08 over BM25 Efficient MCD (31.93% vs 18.85%)

MedMemoryBench reports accuracy across six query types under Efficient and Mixed modes, testing retrieval, temporal updates, and reasoning. These numbers show how MedMemoryBench exposes large drops under noise and highlights methods like Letta and A Mem on specific tasks.

BENCHMARK

By the Numbers

MedMemoryBench reports accuracy across six query types under Efficient and Mixed modes, testing retrieval, temporal updates, and reasoning. These numbers show how MedMemoryBench exposes large drops under noise and highlights methods like Letta and A Mem on specific tasks.

BENCHMARK

Main results on MedMemoryBench under the Efficient setting

Average response accuracy (%) across six query types on MedMemoryBench Efficient.

BENCHMARK

Main results on MedMemoryBench under the Mixed setting

Average response accuracy (%) across six query types on MedMemoryBench Mixed with noise.

KEY INSIGHT

The Counterintuitive Finding

MedMemoryBench shows that adding more memory through Mixed noise consistently reduces performance, for example IG accuracy 43.60% → 25.60% and MCD 24.50% → 10.25% for Unstructured Long Context.

This is counterintuitive because developers expect larger memory stores to help, but MedMemoryBench demonstrates that redundant, homogeneous entries trigger memory saturation and harm reasoning robustness.

WHY IT MATTERS

What this unlocks for the field

MedMemoryBench gives researchers a medically grounded way to stress test memory mechanisms under streaming accumulation, trap events, and realistic noise, rather than static, clean histories.

Builders can now design and compare memory systems that explicitly manage saturation, retrieval granularity, and safety critical personalization, moving toward production ready healthcare agents with reliable long term memory.

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