Real-World Data vs Clinical Trials: How They Fit Together

Real-world data and clinical trials describe different aspects of research. One concerns where information comes from. The other concerns how an intervention is studied. Choosing an evidence strategy starts with the question you need to answer.

Understand the terms

FDA describes real-world data as health-related information routinely collected from sources such as health records, claims, registries and certain digital technologies. Real-world evidence is clinical evidence about a medical product’s use and potential benefits or risks derived from analysis of those data. These definitions belong to FDA’s medical-product framework, not a special supplement approval pathway. FDA: Real-World Evidence

Related reading: decentralized clinical trials and real-world evidence guide

A wearable recording collected specifically for a trial is not automatically real-world data simply because the participant was at home. Data source, study design and participation location should be described separately.

Compare the study designs

An observational study does not assign the intervention being evaluated. A randomized controlled trial assigns participants to groups by chance. Clinical trials are not all randomized, blinded or placebo-controlled.

Randomization and an appropriate comparator help researchers assess whether an intervention caused an outcome. Associations in observational data and changes from baseline alone do not establish a product benefit. FTC guidance generally expects randomized, controlled human testing for health-benefit advertising. FTC: Health Products Compliance Guidance

Ask the right questions before choosing an approach

Use this planning checklist when discussing a study:

• What decision should the findings inform?
• Are we studying feasibility, patterns of use or a defined benefit?
• What comparison would answer that question?
• Which population, product, dose and assessment period are relevant?
• Which measurements are necessary, and how will missing observations be handled?
• What limitations would prevent a stronger conclusion?

Request a written explanation of the design and its tradeoffs. Do not assume that a study described as real-world will be faster, cheaper, more representative or sufficient for marketing claims.

Match the evidence to the proposed claim

FDA’s supplement substantiation guidance emphasizes the relevance and quality of the evidence and the full body of research, including conflicting findings. There is no single study count that establishes support for every claim. FDA: Dietary Supplement Claim Substantiation

Have the actual claim reviewed alongside the study, rather than treating a research label as a guarantee of adequate substantiation.

Plan the methods before collecting data

Our clinical research methodology and evidence guide explains measurement selection, missing data and study limitations. For device-specific planning, read our guide to wearables in decentralized clinical trials.

Bring your research question and existing evidence when discussing a study through Reputable’s clinical research platform.