Should We Still Believe in Randomized Controlled Trials in Nephrology

The randomized controlled trial (RCT) is the cornerstone upon which clinical decision-making is based. Pivotal RCTs in the nephrology area efficiently demonstrated the renoprotective effects of treatment with renin-angiotensin system inhibitors in patients with diabetic and non-diabetic proteinuric nephropathies. However, there is concern about the increasing cost, complexity and duration of clinical studies. Moreover, recent large RCTs addressing key issues for patients with renal disease failed to achieve definitive conclusions mainly due to critical flaws in the investigational strategies, including the adoption of excessive/fixed doses of the study medications, inappropriate use of the placebocontrolled design, enrollment of low-risk individuals, poor reporting of adverse events or unreliable evaluation of renal function. The information now available on the biases that characterize the current RCTs should serve as a tool to rethink the design, patient selection and implementation of future RCTs in nephrology.