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# Confusion Over RWD and RWE: Perspective
- URL: https://www.fdaweb.com/confusion-over-rwd-and-rwe-perspective/
- Published: 2022-05-03T12:00:00.000Z
- Updated: 2026-09-14T17:43:08.000Z
- Author: David McFarland
- Tags: Drugs, Devices, #legacy-id-D5151734

Writing in a *New England Journal of Medicine* Perspective piece, CDER executives **John Concato** and **Jacqueline Corrigan-Curay** say that more than five years after the passage of the 21st Century Cures Act, the terms real-world data (RWD) and real-world evidence (RWE) continue to be used inconsistently and sometimes interchangeably. “This imprecision has complicated efforts to assess the impact of such data and evidence and hindered attempts to track their use,” they [write](https://www.nejm.org/doi/10.1056/NEJMp2200089?ref=fdaweb.com).

After giving the definitions of RWD and RWE that FDA uses, the two say there are two widespread misconceptions about the terms. The first, they say, is the notion that RWD and RWE were new concepts in 2016, while the second is that a simple dichotomy between randomized, controlled trials and observational studies delineates the entire landscape of study design.

“Correcting these misconceptions requires recognition that the degree of reliance on RWD varies with the type of study design and that, by definition, randomized controlled trials that incorporate RWD generate RWE,” the article concludes.