Implement High-Leverage and Layered Risk-Reduction Strategies Using ISMP’s Hierarchy of Effectiveness

Healthcare is a complex and multifaceted field where some level of risk is ever-present. The groundbreaking 1999 Institute of Medicine report, "To Err is Human," rocked the world by estimating that as many as 98,000 deaths occur each year due to preventable medical errors, underscoring the unavoidable reality of human error in healthcare.¹ Acknowledging this, we must recognize that even the most dedicated among us are prone to lapses and mistakes. The inherent complexity of healthcare systems, coupled with the unavoidable potential for human error, creates a significant challenge to patient safety.

In order for organizations to minimize preventable errors, they must actively seek out and mitigate inherent, pervasive risks in the system. To achieve this, we must focus on enhancing both system and human reliability. This includes prioritizing error prevention, ensuring errors are reported when they occur, and diligently mitigating harm to patients if an error reaches them. Creating a truly safe healthcare system typically requires multiple strategies, balancing system and human reliability with ease of implementation, categorized by those that are high-, medium-, and low-leverage.

ISMP's Hierarchy of Effectiveness of Risk-Reduction Strategies (Figure 1) is a model that provides a multifaceted approach to risk reduction. High-leverage strategies are the most effective because they can eliminate the risk of errors and associated harm by designing out hazards, although they often require complex implementation plans and significant resources. Medium-leverage strategies are easier to implement and help reduce the likelihood of errors and minimize patient harm. However, on their own, they may need periodic updating and reinforcement and will not guarantee 100% patient protection. Certain medium-leverage strategies also pose a risk to workflow and alert fatigue if they do not have governance around them (e.g., having multiple checklists or electronic health record [EHR] alerts may have untold consequences if too many are implemented and then become burdensome). Low-leverage strategies aim to improve human performance and are generally easy and quick to implement. However, they are the least effective strategies for error prevention, but, unfortunately, they are frequently relied upon as the sole means to mitigate risk.

Figure 1. ISMP's Hierarchy of Effectiveness of Risk-Reduction Strategies.

Since low-leverage strategies rely heavily on modifying human behaviors and habits, they prove to be the least effective overall. Conversely, high-leverage strategies focus on systemic changes and are more challenging to implement, but they offer a more robust and sustainable approach to minimizing risk within the organization. Medium-leverage strategies are situated between these two extremes, offering a moderate level of effectiveness with a corresponding level of implementation difficulty. So, using multiple strategies with varying leverages is essential for mitigating risks and improving patient outcomes.

In our June 4, 2020 article, Education Is “Predictably Disappointing” and Should Never Be Relied Upon Alone to Improve Safety, we cautioned against relying solely on education as a risk-reduction strategy. While fundamental for knowledge and skill development, education is less effective in our risk-reduction hierarchy than system-focused strategies like forcing functions and automation. Education does not guarantee that the new information has been learned, will be correctly applied in the right circumstances, and will lead to the desired skills. Additionally, knowledge and skills may erode over time, especially if they are not needed or not reinforced through routine activities. The most impactful strategies do not rely on human memory and make it difficult to make mistakes, while also making it easy to do things right. Education alone simply cannot achieve this level of inherent safety.

The real power of this model comes from a layered and comprehensive approach, leveraging interdisciplinary medication safety expertise in the building of the risk mitigation strategies to maximize their quality and effectiveness at each level. A single risk-reduction strategy is rarely enough. Actions must be broad, influencing as many steps of the medication-use process as possible, from procurement and storage to prescribing, dispensing, administration, and disposal. For instance, staff education (a low-leverage strategy) combined with forcing functions and fail-safes (high-leverage strategies) creates a more robust system. This layered approach addresses vulnerabilities at multiple points, and by integrating both human and system reliability enhancements, organizations create a more resilient safety net, minimizing the chances of errors reaching the patient.

When developing and designing risk-reduction plans, we encourage organizations to use this model and refer to Table 1 for descriptions and examples of the strategies listed, from most to least effective based on the science of human factors engineering.

High-Leverage

Forcing functions are high-leverage system strategies offering the greatest effectiveness in mitigating risks. These are design features, procedures, or tasks that compel specific actions and prevent undesirable outcomes by ensuring predetermined conditions are met, enforcing proper usage, highlighting errors, and preventing unintended consequences. Constraints eliminate the opportunity for error by making a critical step unavoidable. By making certain actions prerequisites, forcing functions create a necessary safeguard in the system where the proper sequence of actions is actively enforced, ensuring a more reliable and predictable outcome.

Barriers and fail-safes represent another highly effective strategy for reducing risk. Barriers place limitations or restrictions that are designed to prevent unintended actions, reduce access to dangerous process steps, and minimize potential harm. Fail-safes employ procedures or equipment design features to prevent malfunctioning or unintentional operation by automatically reverting a system to a predetermined safe state in the event of a failure.

Automation and computerization represent the last high-leverage strategy for enhancing system reliability and mitigating risks. This includes taking a look at the whole process and identifying ways to simplify it by removing unnecessary steps, while providing technological support. Automation can decrease variability in practice, thereby improving consistency, reliability, and efficiency. Computerization uses technology to replace manual systems and prevents communication failures, which enhances accuracy and streamlines workflows. This integrated approach reduces the potential for human error and creates a more robust and interconnected system.

Medium-Leverage

Medium-leverage risk-reduction strategies include standardization and protocols; redundancies; and warnings, alerts, reminders, and checklists. These strategies rely on both systems and human vigilance for their reliability, requiring consistent application and monitoring.

Standardization and protocols involve the creation of clinically sound, uniform models of care or product designs to reduce variation and complexity. This increased predictability minimizes the potential for errors from inconsistent practices and product differences.

Redundancies create an extra layer of defense, ensuring that no single failure can cause harm. Redundancies ensure that if the primary pathway fails, a secondary pathway can detect the error and prevent adverse consequences. Similar to any workflow, this process needs to be reviewed and analyzed to ensure that the redundancy is effective and does not create undue burden on the system or have negative downstream effects.

Warnings and alerts serve as notifications that signal a potential problem or hazard requiring immediate attention, prompting swift corrective action. Reminders function as prompts designed to trigger a specific action or help to recall information at a designated time, proactively ensuring adherence to protocols and preventing oversights. Warnings, alerts, and reminders should be reviewed on a regular basis to ensure they do not become nuisance alerts and continue to achieve the intended outcome.

Checklists are structured tools used to ensure consistent and accurate completion of all required steps in a process, promoting thoroughness and minimizing the risk of omitted tasks.

Low-Leverage

Low-leverage strategies can serve as foundational elements in a comprehensive medication safety program. While these strategies primarily rely on human diligence and are most effective when used in conjunction with medium- or high-leverage strategies to create a robust safety net, they play a supportive role in fostering a culture of safety. It is important to understand that relying solely on low-leverage strategies will be insufficient for achieving significant and sustained reductions in medication errors, highlighting the need for a multifaceted approach.

Examples of these supportive strategies include rules and policies, formally established guidelines and directives designed to govern behavior and reduce variability, which are important but frequently violated and therefore unreliable; educational programs, which are structured learning initiatives intended to enhance the knowledge, skills, and competency of healthcare professionals; readily available information that includes accurate and up-to-date resources related to medications, patient information, and relevant guidelines; and informal suggestions or encouragement to staff to exercise increased vigilance and attention to detail, which can reinforce a sense of personal responsibility and commitment to safe practices.

Summary

Recognizing the inherent complexities of healthcare and the unavoidable presence of risk, ISMP's Hierarchy of Effectiveness of Risk-Reduction Strategies provides a practical roadmap for navigating the challenging landscape of medication safety. This model guides organizations to prioritize systemic changes and not rely solely on human diligence, fostering meaningful and lasting reductions in preventable errors, while acknowledging the ever-present challenge of achieving a risk-free environment. Implementing layered mitigation strategies based on this hierarchical model is crucial, demanding a balanced combination of high-, medium-, and low-leverage approaches. While the most effective strategies often require systemic changes that can be challenging to implement, they offer the greatest potential for creating a safer environment for patients and providers alike. By embracing this comprehensive approach and continually striving for improvement, healthcare organizations can move closer to the goal of zero preventable errors.

Table 1. Examples of high-, medium-, and low-leverage risk-reduction strategies.

References

1. Institute of Medicine (US) Committee on Quality of Health Care in America, Kohn LT, Corrigan JM, Donaldson MS, eds. To Err is Human: Building a Safer Health System. National Academies Press (US); 2000.

Citation

Institute for Safe Medication Practices (ISMP). Implement high-leverage and layered risk-reduction strategies using ISMP’s hierarchy of effectiveness. ISMP Medication Safety Alert! Acute Care. 2026;31(1):1-4.