To the Editor.
—Fried et al1 should be commended for their well-designed clinical trial. However, several questions remain to be clarified.A total cholesterol level "greater than the 90th percentile for age" and "morbid obesity" were both listed as exclusion criteria. What were the reference standards for these criteria?All subjects in the coffee-drinking groups were instructed to prepare 1260 mL of coffee daily. However, they drank only 720 mL or 360 mL of coffee depending on the group to which they were allocated. Why was such a large quantity prepared? Could the availability of more than 500 mL of unnecessary coffee lead to higher consumption than the study design required?The compliance check using a 24-hour urine specimen was clever and innovative. However, it would be useful to know how often these checks were made and if they were taken at uniform time points for all subjects. Furthermore,
Kokjohn K. Coffee and Plasma Lipid Levels. JAMA. 1992;268(14):1858. doi:10.1001/jama.1992.03490140066030