Non Interventional Study / Trial: Simple Definition, Types

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What is a Non Interventional Study?

Non Interventional Study
Non interventional studies are a type of observational study.
In general, a non interventional study (NIS) (also called a non interventional trial) is where a patient takes regular medicine, prescribed according to the label. In an NIS, the researcher sets out to exert as little influence as possible on the patient’s condition while studying a medicine’s “…effectiveness, safety and tolerability under real life conditions” (Mishra & Vora, 2010).

One of the major benefits of NIS is to take a trial out of the tightly controlled, laboratory setting of the clinical trial. Non-interventional studies give researchers an opportunity to see how a drug or procedure performs in real-life situations.

External validity (the ability of a study to be generalized to the real-world) tends to be higher with non-interventional trials compared to clinical trials.

UK and EU Definition

The term “non-interventional” has a very specific meaning when it comes to the United Kingdom’s Medicines Act of 1968. The Act controls the use of pharmaceuticals for human or veterinary purposes, including the manufacture and supply of medicines. Aronson (2004) states… “the term ‘non-interventional’ in the Directive doesn’t mean non-interventional (i.e. non-interference) at all; it refers to an intervention with a licensed medicinal product.”

Medicines used during an NIS must be prescribed according to the label indications; no “off-label” (e.g. experimental or non-FDA approved) medications are allowed. If this condition is violated, the study is classified as a clinical trial. Therefore, a study is either non-interventional, or it’s a clinical trial— there’s no gray area.

The EU Directive (2001/20/EG article 2c) defines non interventional studies in a similar way, as

“studies where the medicinal products are prescribed in the usual manner in accordance with the terms of the marketing authorisation. The assignment of the patient to a particular therapeutic strategy is not decided in advance by a trial protocol but falls within current practice and the prescription of the medicine is clearly separated from the decision to include the patient in the study.”

Types of Non Interventional Study

Case-control, Cohort and other observational studies are non-interventional by definition. They are observational studies, which means that the researcher only observes the patients. Registries, which keep track of post-approval side effects and efficacy (how well a drug works) are also considered non-interventional.


Aronson, J. (2004). What is a clinical trial? British Journal of Clinical Pharmacology. Jul; 58(1): 1–3.
EU Directive. (2001). Directive 2001/20/EC Of The European Parliament And Of The Council. Retrieved November 22, 2017 from
Mishra, D. & Vora, J. Non interventional drug studies in oncology: Why we need them? Perspect Clin Res. Oct-Dec; 1(4): 128–133.
Nahler, G. Dictionary of Pharmaceutical Medicine. Springer, 2017.

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