Simple Science

Cutting edge science explained simply

# Computer Science # Machine Learning # Artificial Intelligence # Cryptography and Security

Protecting Patient Data: The Threat of SurvAttack

SurvAttack highlights risks in survival models and the need for stronger defenses in healthcare.

Mohsen Nayebi Kerdabadi, Arya Hadizadeh Moghaddam, Bin Liu, Mei Liu, Zijun Yao

― 6 min read


SurvAttack: A Wake-Up SurvAttack: A Wake-Up Call safety. survival models, risking patient SurvAttack exposes vulnerabilities in
Table of Contents

Survival Models are tools used in healthcare to estimate how long a patient might live or how soon they might experience a certain medical event, such as developing a serious condition. These models analyze electronic health records (EHRs), which are digital versions of patients' paper charts. They include a wealth of information, such as medical history, treatments, and outcomes, helping healthcare providers assess risks and prioritize patients needing urgent care.

The Importance of Robust Models

With so much at stake, it's crucial that these survival models are reliable. If a model makes a mistake, it could mean that a patient who needs immediate attention gets pushed down the priority list while others who aren't in urgent need take precedence. Think of it like a restaurant where the chef mixes up the orders: instead of serving the food to the hungriest customers first, they give it to those who just ordered a salad when there’s a starving person at the door.

The Challenge of Adversarial Attacks

However, survival models face threats. For example, someone might try to trick these models by changing patient data slightly, which could lead to incorrect predictions. This tactic is called an adversarial attack. In simple terms, it’s like someone sneaking into your kitchen, swapping the salt with sugar, and watching you bake a cake that no one wants to eat. In healthcare, this could have dire consequences.

What is SurvAttack?

To counter these adversarial attacks, researchers have developed a new framework called SurvAttack. This black-box adversarial attack method focuses specifically on survival models. A black-box method means that the attacker doesn’t have access to the inner workings of the model; they can only see the input and the output. So, imagine trying to guess how a magician performs a trick without knowing the secrets behind the scenes!

How SurvAttack Works

SurvAttack uses a clever method to simulate what might happen if malicious changes were made to patient data. It introduces slight changes to the data while keeping the overall meaning intact, somewhat like swapping an apple for a green apple. The goal is to confuse the model enough to make it provide the wrong predictions without making it obvious that something has changed.

Perturbations: The Sneaky Changes

The changes made in SurvAttack are known as perturbations. These are tiny alterations in the Medical Codes within a patient's EHR. For example, instead of saying a patient has a specific diagnosis, the model might be tricked into thinking they have a different, less severe condition. This could result in a patient being ranked lower on the urgency list, delaying their treatment. It's like if someone said they were feeling a little under the weather, but what they really needed was to see a doctor right away!

Three Key Steps in SurvAttack

SurvAttack follows a series of steps to effectively carry out its task. The process involves selecting which parts of the data to change, how to change them, and measuring the impact of these changes on the survival model.

Step 1: Selecting Medical Codes

The first step in SurvAttack is choosing which medical codes to alter. Medical codes classify a patient's condition or treatment, and there are thousands of them. To make informed choices, the model uses medical knowledge to find codes that are similar in meaning but could lead to different predictions.

Step 2: Evaluating Changes

Once the codes are selected, the next step is to evaluate potential changes. This involves assessing how a particular alteration could affect the model's predictions. The goal is to ensure that the changes do not stray too far from the reality of the patient's condition while still being impactful enough to confuse the model.

Step 3: Executing the Attack

After determining how to change the codes, SurvAttack moves on to executing the attack. This step involves modifying the patient's records and checking to see if the model's output changes in the desired direction. If the predictions shift, the attack may be deemed successful. If not, the model can try different changes until it finds one that works.

The Importance of Clinical Consistency

One of the clever aspects of SurvAttack is that it ensures all changes remain clinically meaningful. This means the alterations still need to make sense within the medical context. For example, if a patient's diagnosis changes, it should still be a diagnosis that's plausible for their condition. If the model were tricked into thinking someone had a totally unrelated condition like a broken leg when they actually had a respiratory issue, it wouldn't just be an attack- it would be a recipe for disaster.

Measuring the Success of an Attack

To assess the effectiveness of SurvAttack, researchers use specific metrics. The main goals are to disrupt the model’s ability to correctly rank patients by their urgency and to mess with its predictions about survival times. If the model fails to prioritize patients correctly or predict their survival properly, it indicates that SurvAttack has achieved its goal.

The Real-World Implications of SurvAttack

SurvAttack shines a light on the weaknesses of survival models and prompts necessary discussions about security in healthcare. With the potential to manipulate patient data, attackers could cause serious harm by hindering a model's ability to prioritize care effectively-a situation no one wants to find themselves in.

Conclusion: The Need for Caution

The development of SurvAttack serves as a reminder of the importance of building robust systems in healthcare. Just like how we lock our doors at night, safeguarding these models against potential threats is crucial for ensuring that patients receive the care they need when they need it most. Each patient’s survival could depend on it. The stakes are high, and the healthcare industry must remain vigilant against these types of attacks to protect vulnerable individuals who are counting on their survival models to provide accurate, timely predictions.

And who knows, maybe one day, with enough innovation, we’ll have a system that’s so secure not even the most cunning tomato thief will be able to slip past!

Original Source

Title: SurvAttack: Black-Box Attack On Survival Models through Ontology-Informed EHR Perturbation

Abstract: Survival analysis (SA) models have been widely studied in mining electronic health records (EHRs), particularly in forecasting the risk of critical conditions for prioritizing high-risk patients. However, their vulnerability to adversarial attacks is much less explored in the literature. Developing black-box perturbation algorithms and evaluating their impact on state-of-the-art survival models brings two benefits to medical applications. First, it can effectively evaluate the robustness of models in pre-deployment testing. Also, exploring how subtle perturbations would result in significantly different outcomes can provide counterfactual insights into the clinical interpretation of model prediction. In this work, we introduce SurvAttack, a novel black-box adversarial attack framework leveraging subtle clinically compatible, and semantically consistent perturbations on longitudinal EHRs to degrade survival models' predictive performance. We specifically develop a greedy algorithm to manipulate medical codes with various adversarial actions throughout a patient's medical history. Then, these adversarial actions are prioritized using a composite scoring strategy based on multi-aspect perturbation quality, including saliency, perturbation stealthiness, and clinical meaningfulness. The proposed adversarial EHR perturbation algorithm is then used in an efficient SA-specific strategy to attack a survival model when estimating the temporal ranking of survival urgency for patients. To demonstrate the significance of our work, we conduct extensive experiments, including baseline comparisons, explainability analysis, and case studies. The experimental results affirm our research's effectiveness in illustrating the vulnerabilities of patient survival models, model interpretation, and ultimately contributing to healthcare quality.

Authors: Mohsen Nayebi Kerdabadi, Arya Hadizadeh Moghaddam, Bin Liu, Mei Liu, Zijun Yao

Last Update: Dec 24, 2024

Language: English

Source URL: https://arxiv.org/abs/2412.18706

Source PDF: https://arxiv.org/pdf/2412.18706

Licence: https://creativecommons.org/licenses/by/4.0/

Changes: This summary was created with assistance from AI and may have inaccuracies. For accurate information, please refer to the original source documents linked here.

Thank you to arxiv for use of its open access interoperability.

Similar Articles