Recruitment experience in the full-scale phase of the Modification of Diet in Renal Disease Study

The Modification of Diet in Renal Disease (MDRD) Study is a randomized, multicenter clinical trial testing the effects of three different levels of dietary protein and phosphorus intake and two levels of blood pressure control on the rate of loss of kidney function in persons with various chronic kidney diseases. During a 27-month recruitment period, 2507 persons who had objective evidence of impaired kidney function were screened at 15 centers. Eight hundred and forty men and women aged 18-70 with a glomerular filtration rate between 13 and 55 ml/min/1.73 m2 were randomized. Medical record review was the primary means of identifying study participants at the beginning of recruitment. Later, use of mass media was instrumental in alerting both the public and the medical community of the need for MDRD Study participants. Overall, the most important sources of randomized participants were referral by personal physician (45.4%) and relative/friend (5.6%), and self-referral after hearing about the trial from newspapers (23.9%) and television (5.2%). Review of medical records from defined patient populations was the source of 22.3% of the randomized study participants. A total of 9.4% of the randomized participants called a toll-free (800) telephone number before contacting the centers.