To the Editor.
—In a recent letter, Dr Sawicki and colleagues1 question whether captopril has kidney-protecting properties and, therefore, whether it is superior to conventional antihypertensive treatment. In formulating their argument, the authors quote information that is not accurate with respect to our own publication.2 For example, the rates of loss of creatinine clearance they attributed to patients in our study were much higher than those that we actually experienced. As we noted, we carried out a logarithmic transformation of sequential measurements of the creatinine clearances to improve the distributional assumptions of a simple, linear, random-effects model. We reported the rate of change as a percentage per year, rather than milliliters per minute per year. The placebo group diminished their creatinine clearance at a rate of 17% per year, as opposed to the captopril group, which lost function at 11% per year (P=.03). We believe that this