Providing Guidance in the Dark: Rare Renal Diseases and the Challenge to Improve the Quality of Evidence

Davide Bolignano; Evi V. Nagler; Wim Van Biesen; Carmine Zoccali


Nephrol Dial Transplant. 2014;29(9):1628-1632. 

In This Article


No specific and validated methods for designing, carrying out or analysing clinical trials in small populations exist. Although high-quality data adhering to good clinical practice standards are desirable, a more pragmatic attitude can be justified in certain situations. However, a careful balance between potential benefit and harm, not only for the individual patient but also for the society at large, should be maintained, to avoid either that effective treatments are withheld, or useless treatments provided. At least, the guidance should be made transparent, by providing a crisp description of how the literature was searched, how retrieved evidence was interpreted, and what considerations were taken into account when formulating the recommendation. The use of 'expert groups' supported by a team of methodologists, where consensus between experts in the field of the disease is obtained during balanced face-to face discussions, might be a possible way to balance personal experience and available (as few as it might be) evidence.