Effective treatment of four consecutive idiopathic membranous nephropathy patients.

lies in the way information on ACEI/ARB treatment was obtained. In the study of Opelz et al., a questionnaire was sent out, with a return rate of 107 out of 299 participating centres. Their publication does not provide information on how completely the data was collected within those 107 centres. By contrast, we used data bases from the general public Austrian Sickness Funds and direct entry from patient charts. (ii) Furthermore, we included the confounding variables in a time-varying manner. Different strategies to identify confounding variables yielded virtually the same results. Finally, we did not explicitly recommend ACEI/ARB use, we rather encouraged the scientific community to test a potentially causal relationship between ACEI/ARB use and increased survival in a randomized controlled clinical trial.