Clinical Research & Regulatory
Real-World Data (RWD) and Real-World Evidence (RWE)
Where real-world data come from, how they become evidence, and how RWE complements randomized controlled trials.
Randomized controlled trials tell us whether a treatment works under ideal conditions. Real-world data and real-world evidence tell us how it performs in everyday practice, for the patients who actually receive it.
What is real-world data (RWD)?
Real-world data are data on patient health status and the delivery of healthcare, routinely collected from a variety of sources, such as:
- Electronic health records
- Claims and billing activities
- Product and disease registries
- Patient-generated data, including from home-use settings
What is real-world evidence (RWE)?
Real-world evidence is the clinical evidence on the use and potential benefits or risks of a medical product, derived from the analysis of RWD. RWE can be generated by different study designs, including pragmatic randomized trials and observational studies (prospective and retrospective).
Why RWE matters
RWE shows how a treatment works outside the controlled setting of a clinical trial. Suppose an RCT shows a drug lowers blood pressure in a carefully selected hypertensive population. Without further evidence, it may be inappropriate to assume the same results for every hypertensive patient seen in daily practice.
RCTs vs RWE
RCTs are the studies that establish the safety and efficacy of an investigational product. They are designed for internal validity: results that are reliable, true and not due to error. That focus can compromise generalizability:
- RCTs enrol very selective populations, often excluding patients with comorbidities.
- They run in tightly controlled settings with strict inclusion and exclusion criteria.
- Most treatment guidelines are built on RCT results, which may not represent the entire patient population.
RCT results therefore benefit from support across the diverse situations of real-world clinical practice.
Advantages of RWE
RWE also supports patient outcomes research, health economics and a better understanding of current healthcare services.
RWE in practice: three study designs
Retrospective study
A Swedish study evaluated how closely type 1 diabetes guidelines, which recommend HbA1c testing quarterly or more often in uncontrolled patients, were followed in practice. Using the Diab-Base electronic medical record database, it included 5,989 patients from 10 outpatient clinics. HbA1c was measured less often than the guidelines recommend.
Prospective study
LANDMARC is a prospective, multicentre study following a large cohort of people with type 2 diabetes across India for three years. It aims to reveal trends in complications, treatment strategies and the relationship between treatment, control and complications.
Cross-sectional study
A study across 178 sites in India assessed dyslipidaemia control in diabetic patients treated with lipid-lowering drugs. Control was very poor, with almost half of patients not reaching their LDL-cholesterol goal.
Key takeaways
- RWD is routinely collected health data. RWE is the clinical evidence derived from analysing it.
- RCTs maximize internal validity, while RWE extends findings to real-world populations.
- RWE can be faster, broader and better at detecting rare safety signals.
- Retrospective, prospective and cross-sectional designs all generate valuable RWE.
References
- US Food and Drug Administration. Framework for FDA’s Real-World Evidence Program. 2018.
- Bhatt A. Conducting real-world evidence studies in India. Perspect Clin Res. 2019;10:51-56.
- Kim HS, Lee S, Kim JH. Real-world evidence versus randomized controlled trial: clinical research based on electronic medical records. J Korean Med Sci. 2018;33:e213.
- Monti S, Grosso V, Todoerti M, Caporali R. Randomized controlled trials and real-world data: differences and similarities to untangle literature data. Rheumatology. 2018;57:vii54-58.
- National Academies of Sciences, Engineering, and Medicine. Real-World Evidence Generation and Evaluation of Therapeutics: Proceedings of a Workshop. Washington (DC): National Academies Press; 2017.
- Makady A, de Boer A, Hillege H, Klungel O, Goettsch W. What is real-world data? A review of definitions based on literature and stakeholder interviews. Value Health. 2017;20:858-865.
- Matuleviciene V, et al. A retrospective study in 5,989 patients with type 1 diabetes in 10 outpatient diabetes clinics in Sweden of the frequency of measuring HbA1c in clinical practice. J Diabetes Metab. 2014;5:5.
- Das AK, et al. Rationale, study design and methodology of the LANDMARC trial. Diabet Med. 2020;37:885-892.
- Mithal A, et al. Prevalence of dyslipidemia in adult Indian diabetic patients: a cross-sectional study (SOLID). Indian J Endocrinol Metab. 2014;18:642-647.
Knowledge check
Test yourself in 3 questions
0 / 3 answered
Question 1 of 3
Which statement correctly describes RWD and RWE?
Correct answer: A. RWD are the raw data from sources like health records, claims and registries. RWE is the clinical evidence produced by analysing RWD.
Question 2 of 3
Which RCT limitation does RWE mainly help address?
Correct answer: B. RCTs maximize internal validity in selected populations. RWE shows how treatments perform in the wider, real-world population.
Question 3 of 3
The Swedish study of HbA1c testing in 5,989 patients is an example of which design?
Correct answer: B. It retrospectively analysed records from the Diab-Base electronic medical record database across 10 outpatient clinics.
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