In contrast to the restrictive nature of randomised controlled trials (RCT), non-interventional studies (NIS) investigate the features of a therapy in daily clinical practice. The observational plan of NIS does not dictate a treatment strategy, but is based on the product label. Unlike RCT, NIS therefore have no actual inclusion and exclusion criteria, allowing the study of broad heterogeneous patient populations.
NIS carried out in Germany with support from the pharmaceutical industry and investigating the use of biologics for the treatment of rheumatoid arthritis were identified and their findings were compared with those from the RCT of the respective biologic.
Analysis of the identified NIS revealed the following: (1) populations in NIS were on average more than twice as large as in RCT, (2) patient characteristics in NIS and RCT were different, (3) the effectiveness of biologics in NIS was comparable to the efficacy observed in RCT, and (4) NIS collected supplementary data, e.g. on usage and dosing in clinical practice.
NIS represent an important tool for the assessment of daily clinical practice. Despite methodological drawbacks, NIS provide valuable data that contribute to a more complete picture of the value of treatment with biologics. The English version of this article is available at SpringerLink (under "Supplemental").