Albuminuria as a surrogate marker for drug development: a European Regulatory perspective.

Clinical trials with surrogate end points generally require smaller sample sizes and shorter duration than those with clinical outcomes. However, in practice, surrogate end points are likely to result in less comprehensive conclusions than 'outcome' end points as they sometimes reflect only partial aspects of complex phenomena. A number of conditions help to establish the validity of a particular variable as predictive of clinical outcome. This article discusses to what extent albuminuria fulfills these requisites in two particular clinical scenarios: prevention of renal deterioration and prevention of cardiovascular disease.