There are no published studies of nurse:patient ratios in PD. Many countries and clinics have their own established ratios but none are based on evidence. I have seen huge ranges of nurse:patient ratios from as low as 1:15 to as high as 1:200. Commonly in the US the ratio is 1:25, in South America 1:50, but again there is no evidence for these ratios. One abstract was published last year describing a preliminary study to determine a formula for nurse:patient ratios based upon the actual tasks assigned to nurses, similar to studies previously published to establish ratios for ICU nurses. (Bernardini J. A formula for determining appropriate nurse:patient ratios in PD programs. Perit Dial Int 2009:29;S13)