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Real-world data and study design

Real-world data and study design · RWD / RWE

Real-world data are health and healthcare records routinely collected through sources such as electronic health records, prescriptions, claims and registries. Analysis of suitable data can generate evidence about a medicine’s use, benefits or risks.

How to read it

Separate the source of data from the design of the comparison. Examine population comparability, exposure and outcome definitions, missing information and confounding.

A common pitfall

Real-world data are not synonymous with an observational design or proof of causality. They may support different designs, including randomized trials embedded in routine practice. Person-years describe a time denominator, not data provenance.

Records do not assign treatment

Routine records may omit symptoms that were never brought to care or whether a prescription was actually taken. More records do not automatically resolve missing or inaccurately measured information.

When treatment is not randomized, medicine users may differ in underlying conditions, baseline risks or care-seeking. Adjustment for measured factors cannot automatically remove unmeasured confounding.

Keep the GLP-1 analyses separate

The GLP-1 case includes pooled randomized trials and a separate Sentinel observational comparison. The 6.4 versus 3.8 events per 100000 person-years came from the pooled trials, not Sentinel. Ask who was compared, when follow-up began and how events were identified.

Practice with a case

Read the Chinese case: GLP-1 Why can a rare risk warrant a warning →

The Chinese case separates person-time rates in pooled trials, routinely collected data and observational comparisons.

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Examples in other articles

Related readings will be added as the collection grows.