Drugdu.com expert's response:

In the field of medical devices, risk estimation, risk assessment, and risk rating are crucial steps in risk management, each with its own clear definition and distinction.

Ⅰ. Definitions

1. Risk Estimation

（1）Definition: The process of assigning values to the probability of occurrence and severity of harm.

（2）Content: This typically involves analyzing factors such as the design, manufacturing process, and usage environment of medical devices to identify potential risk points. The purpose of risk estimation is to identify potential risks and provide a foundation for subsequent risk assessment.

2. Risk Assessment

（1）Definition: The process of comparing "estimated risks" with "given risk criteria" to determine the acceptability of risks.

（2）Content: Risk assessment is a more in-depth and systematic process that involves detailed analysis of identified risks, including the likelihood, severity, and effectiveness of risk control measures. The purpose of risk assessment is to determine the priority of risks in order to adopt appropriate risk control measures. Risk assessment usually follows certain standards and procedures, such as ISO 14971.

3. Risk Rating

（1）Definition: The result of risk assessment.

（2）Content: Risk rating is the process of classifying and prioritizing risks based on risk assessment. Risk rating typically categorizes risks into different levels, such as high, medium, and low, based on the likelihood and severity of risks. The purpose of risk rating is to facilitate risk management and control, as well as provide a basis for decision-making.

Ⅱ. Distinctions

1. Differences in Focus

（1）Risk Estimation: Focuses on preliminary prediction and identification of potential risks.

（2）Risk Assessment: Conducts in-depth analysis of identified risks to determine their priority.

（3）Risk Rating: Classifies and prioritizes risks for easier management and control.

2. Differences in Methods

（1）Risk Estimation: Typically uses qualitative, semi-quantitative, or quantitative methods to assign values to the probability of occurrence and severity of harm.

（2）Risk Assessment: Compares estimated risks with given risk criteria to determine their acceptability.

（3）Risk Rating: Classifies risks into different levels based on the results of risk assessment.

3. Differences in Application of Results

（1）Risk Estimation: Provides basic data for risk assessment.

（2）Risk Assessment: Provides input for risk rating and determines the priority of risk control measures.

（3）Risk Rating: Provides a direct basis for risk management and decision-making.

In summary, risk estimation, risk assessment, and risk rating in medical devices are three interconnected but focused steps. Together, they constitute the core framework of risk management for medical devices, providing important safeguards for ensuring the safety and effectiveness of medical devices.