Know your Options when selecting a Study Design – Study type NIS: Non-interventional studies

In scientific research, we principally differentiate between primary and secondary research. While secondary research summarizes study results that are already available by conducting meta-analyses or reviews, in primary research, the actual studies are conducted. A further useful classification of study types in clinical and epidemiological research is interventional and non-interventional (NIS) or observation studies.
Study design selection and thereby also study type dictates the study’s quality, validity and worthiness of publication. Study type is determined by the research question and is the deciding factor regarding the scientific study’s usefulness and interpretability.

Clinical trials are scientific studies that largely reduce influencing and confounding factors by employing inclusion and exclusion criteria as well as a precisely defined study protocol and treatment scheme. In contrast, non-interventional clinical studies are patient-focused observation studies in which patients are treated with an individually assigned therapy. NIS usually investigate pharmaceuticals that have already been licensed and follow an observation plan, which defines the observed case number, analyses methods and observation questions. No treatment specifications are made; the physician determines therapy based solely on medical diagnoses and patients are treated under normal practice conditions. Therefore, the aim of NIS is to observe and assess as large a number of patients using a pharmaceutical as possible. Evaluation is usually conducted retrospectively.
Therapy studies (non-interventional), prognosis studies, pharmaceutical observation studies, secondary data analyses, case series and case-by-case analyses belong to the group of NIS.