Designing Evidence That Supports Access Decisions
How real-world evidence reduces uncertainty and informs decision-making across HTA and U.S. payer environments
Real-world evidence plays an increasingly important role in how organizations approach market access and evidence strategy. It provides a way to address questions that clinical trials are not always designed to answer, including those related to real-world use, long-term outcomes, and system-level impact.
This perspective reflects how real-world evidence is applied across access decision-making in practice, based on themes discussed in the April webinar.
In many organizations, evidence generation is well established, but how that evidence aligns to access decision-making is not always clearly defined. Clinical data provide a critical foundation, but key questions often remain, particularly around how therapies perform in practice and how they impact healthcare systems over time.
The value of real-world evidence begins with understanding where uncertainty exists. Its impact depends on whether it is designed to address the specific questions that shape access decisions.
Access Decisions Are Made Under Uncertainty
HTAs are structured processes used to evaluate whether a therapy should be reimbursed, for whom, and under what conditions.
These decisions are distinct from regulatory approval. Regulators evaluate whether a therapy is safe and effective. HTA bodies evaluate whether it is worth paying for given the available evidence and the broader system context.
These decisions are made in the context of uncertainty, including questions related to long-term outcomes, broader patient populations, real-world use, and total system-level cost.
“HTA bodies are not asking whether a therapy works—they’re asking whether it’s worth paying for, and under what conditions.”
— Jessica Duchen, VP, RWE & HEOR Strategy
In many cases, these uncertainties, rather than the average effect size, shape access outcomes.
Real-world evidence plays a specific role in this context. It does not replace randomized clinical trial data or independently determine access decisions.
Its value lies in reducing uncertainty in areas that directly influence access decisions.
In practice, real-world evidence is most often applied across four key areas:
“Real-world evidence is most valuable when it addresses the specific uncertainties that matter to decision-makers.”
— Michael Murphy, Director, RWE & HEOR Strategy
This reflects how evidence is used to inform access decisions, not simply increase the volume of data.
The role of real-world evidence depends on the specific uncertainty being addressed.
When clinical evidence is limited or immature, real-world evidence reduces uncertainty and enables conditional access approaches, including coverage with evidence development.
When clinical benefit is established but system-level impact is uncertain, real-world evidence informs reassessment by providing insight into outcomes, utilization, and resource use.
“RWE does not replace randomized trial evidence. It reduces uncertainty and supports reassessment over time.”
— Beni Turner, Senior Director, Value & Access Solutions
As additional data become available, real-world evidence enables ongoing decision-making, including refinement of patient populations and continued access over time.
In therapeutic areas with multiple treatment options, real-world evidence can also inform treatment approaches where comparative clinical trial data are limited.
Across access decisions, consistent patterns emerge in how real-world evidence is applied:
These patterns reinforce a central point. Real-world evidence is most influential when it directly reduces the uncertainty that drives access decisions.
Implications for the U.S. Market
While the U.S. does not have a centralized HTA system, similar decision dynamics are present. Payers evaluate clinical benefit, total cost of care, real-world utilization, and population-level impact when making access decisions. This is reflected in formulary tiering, prior authorization, step therapy, and other utilization management approaches.
HTA-like decision-making is already embedded in the U.S., even if it is not formally structured.
Where Evidence Strategies Often Fall Short
In many cases, the challenge is not the amount of evidence, but how it is aligned to decision-making.
Common gaps include:
Without alignment, even robust evidence programs may have limited impact on access decisions.
From Evidence Generation to Evidence Strategy
Real-world evidence is most effective when it is part of a broader, decision-focused strategy.
This includes:
Identifying key uncertainties early
Aligning evidence generation to decision-maker needs
Integrating clinical, real-world, and economic data
Supporting access, reassessment, and lifecycle planning
Designing that alignment requires a clear understanding of how access decisions are made and how evidence is evaluated in practice.
The Bottom Line
Generating evidence alone does not determine access. Its impact depends on whether it addresses the uncertainties that shape decision-making.
Real-world evidence reduces that uncertainty when it is aligned to the right questions at the right time across the lifecycle.
Start a Conversation
Explore how a structured, decision-focused approach to real-world evidence can support access strategy and value demonstration.
Watch the full Magnolia Market Access webinar on Real-World Evidence in Health Technology Assessments for additional perspective on how organizations are applying RWE to inform access decisions.