Hemodialysis is the process of cleaning the blood by removing urea and other waste products through a semipermeable membrane called a dialyzer.⁴ The effect of dialysis dose on mortality was first examined in the National Cooperative Dialysis Study (NCDS)⁵ which found that certain illnesses increased with less than adequate dialysis. Although the NCDS examined adequate levels of dialysis, it did not address optimal levels. Furthermore, the NCDS studied healthy individuals with little or no co-morbid conditions, which is atypical of the dialysis population today. An important observation of the NCDS was that a low protein intake predicted a poor outcome.⁵

Since then, several studies have compared dialysis dose to mortality rates, nutritional measures, and illnesses in observational studies and continue to show a correlation between the amount of dialysis received and mortality rates.^6-9 However, apart from being observational, these reports examined the data retrospectively, which still left questions about the cause and effect between dialysis dose and death rate.

The HEMO study
The Hemodialysis Study (HEMO), conducted from March 1995 through December 2001, investigated the effect of the amount of dialysis received dose and the type of dialyzer membrane used on mortality and morbidity rates. The HEMO Study was a multicenter, prospective, randomized clinical trial with a two-by-two factorial design. Subjects were screened for eligibility during baseline and randomized into one of four treatment groups arising from the 2x2 factorial design:

• Standard dialysis dose and low flux dialyzer
• Standard dialysis dose and high flux dialyzer
• High dialysis dose and low flux dialyzer
• High dialysis dose and high flux dialyzer.

Hypothesis. The primary hypotheses of the study were that hemodialysis with the high dose of dialysis would reduce mortality and morbidity, and hemodialysis with high flux membranes would reduce mortality and morbidity.

Study coordinators
The primary role of the coordinator was to ensure adherence to the study protocol. A principal component of the study was to maintain the targeted dose of dialysis for each two of the dialysis dose groups of subjects. Blood draws were conducted monthly, and a report generated on each subject showed how well the target dose was met. The study coordinator then reviewed the reports with the PI to determine whether changes were indicated in order to maintain adherence to subjects’ randomized group.

As the supervisor, the HEMO Study coordinator was also responsible for recruitment and retention of subjects, supervising personnel, ordering supplies, and scheduling of blood and urine collections according to study guidelines.

Office manager. One of the duties of the study coordinator was to perform the role of office manager. Each office had to be designed to promote an even flow of exchange between data collection, data entry, and subject reports. Email was reviewed daily for subject reports, inquiries, and overall communication between the clinical centers and the DCC and NCC. Because each blood draw generated a minimum of three reports, it was not uncommon to receive anywhere from 20–40 emails per day. Inquiries were generated from discrepancies found within the data and answered by either the study coordinator or the study dietitian. In order to answer the inquiries in a timely manner, files were kept well-organized and up-to-date.

In addition, some study coordinators also helped to prepare and manage the center’s budget, submitted the required documents to the institutional review board (IRB), and prepared continuing grant applications and quality control reports.

Data collector. The HEMO Study used over 35 subject data forms, including nutrition forms, quality of life questionnaires, and forms to determine the severity of co-morbid conditions. Most forms were completed first at baseline, when a subject joined the study, and then annually or semiannually. Forms were completed on a monthly basis—or more often as needed to record the events of the dialysis treatment. Besides collecting the data, several study coordinators also became responsible for data entry, particularly when the clinical center was short staffed.

Another large part of the data collection included obtaining medical record information on all subject hospitalizations and deaths to analyze the primary and secondary outcomes of the study. Once the study coordinator received the medical records and discharge summaries, the PI reviewed the information to determine the cause of death or hospitalization. Admission and discharge diagnoses were coded from a prepared list, entered into the database, and sent to reviewers for confirmation of data. However, it sometimes took as many as two to five requests to get the medical records from the hospitals.

Educator. Results of the blood tests were reviewed monthly with subjects, who were informed either that the dialysis treatment met the target or that the treatment needed adjustment. If the dialysis prescription required adjusting, several options were presented to the subject. Factors that had to be taken into account when adjusting the dialysis prescription included the amount of time the subject was willing to spend on dialysis, subject symptoms, and whether or not the subject had any previous reactions to a certain dialyzer.

Public relations. At each clinical center, subjects were recruited from various dialysis units. Effective communication with the non-HEMO Study staff was essential to organize clinic operations. Cooperation was needed for drawing blood, to obtain hospitalization information, and to deliver the appropriate amount of dialysis, because constant adjustments to the dialysis prescription were required to achieve and/or maintain the randomized intervention.

Study coordinators routinely conducted in-services at the clinic to ensure proper blood drawing and reporting techniques. The dialysis center staff was also instructed to report any interruptions or changes that occurred throughout the dialysis treatment to ensure data integrity.

Recruiter. Each clinical center was expected to recruit and maintain at least 60 subjects in the study at all times for a total of 900 subjects using a recruit-to-replace strategy. The HEMO Study offered no monetary compensation for participation. Various incentives, however, included giving subjects small gifts, free vitamins, and free high-calorie oral nutritional supplements.

Steering Committee meeting participant. Study coordinators participated in Steering Committee meetings to review the progress of the study and to discuss possible changes that might improve it. HEMO dietitians were also encouraged to attend the meetings and offer suggestions to the nutrition committee on ways to improve nutritional aspects of the study.

Nutrition component
The Nutrition Committee was important because it provided direction and recommendations to the Steering Committee on how to implement the nutrition component of the study. The goal was to ensure subject safety and to examine the effects of diet and malnutrition on hemodialysis subjects. Some of the major tasks for the HEMO registered dietitian (RD) were to:

• perform anthropometric measurements.
• collect appetite assessment data and supplement intake using nutrition questionnaires.
• conduct nutrient analyses from two-day diet diaries using Nutritist IV or Five software program.
• respond to declining serum albumin and/or undesired weight loss in subjects.
• maximize subject well-being and ensure that the nutritional standards of care were met.

Anthropometric measurements were taken initially at baseline and then yearly. The measurements were taken within 10 hours of a subject’s treatment to avoid an overestimation of dry weight from excessive fluid gains and to provide an estimate of lean body mass.

Diet diaries were recorded annually by the subjects on a dialysis and a nondialysis day. These were was carefully reviewed with the subject, entered into a nutrition analysis program to determine calorie, protein, and nutrient intake, and then transmitted to the DCC via an FTP file.

To ensure that nutrition standards of care were met, each HEMO Study RD was expected to work closely with the clinic dietitian. According to the HEMO Study manual of operations the role of the RD was to counsel the subject in response to abnormal serum chemistries such as BUN, creatinine, potassium, phosphorus, sodium, calcium, bicarbonate, albumin, and nPCR, and/or interdialytic fluid gains. The dietitian will evaluate abnormal chemistries or large fluctuations in chemistries with consideration being given to nutritional status, diet intake, active medical issues and dialysis prescription. The role of the nutrition program in HEMO, in its entirety, is described in a separate paper.¹¹

Dietitian as research coordinator
Many dietitians are familiar with dialysis dose and adequacy calculations. This is particularly the case with renal dietitians—who specialize in the care of people with kidney disease—because the protein catabolic rate (PCR is the breakdown rate of proteins) is derived from these calculations.5 In fact, it is often the responsibility of the RD to review both the dialysis adequacy and the PCR with patients each month.

In the study, RDs collected annual diet diaries during the same week as the blood draw in order to compare the dietary protein intake (DPI) with the PCR. Access to simultaneous DPI and PCR records allowed investigators to determine whether subjects were anabolic (building lean tissue), catabolic (breaking down lean tissue), or in neutral nitrogen balance (stable). PCR, however, is dependent on the accuracy of the data from the dialysis session.⁵

Even if a dietitian’s primary role was not study coordinator, to increase efficiency and prevent an overlap in staffing HEMO RDs often monitored blood draws and completed nonnutritional study forms when they collected the dietary data. Thus, many RDs functioned as assistant study coordinators in addition to being HEMO Study dietitians (see Clinical Centers box).

Some RDs were already employed as the dietitian at the dialysis unit where recruiting for HEMO Study took place. Thus, the RDs were familiar with the subjects and the staff long before the start of the study. Likewise, the subjects and staff were familiar with the dietitian, which created a trusting and friendly atmosphere. The free renal vitamins and oral nutrition supplements dispersed by HEMO Study RDs increased the attractiveness of the study to potential subjects.

Challenges
An advantage of having a dietitian as study coordinator was the large nutrition component of the study and the fact that many renal dietitians were already familiar with dialysis dosing. On the other hand, some obvious, but not insurmountable, challenges faced the dietitians who functioned as study coordinators.

Blood draws and urine collections. To ensure quality data, the blood had to be drawn, processed, and stored according to guidelines established by the study protocol and the manual of operations. Therefore, a dietitian needed to understand how to collect evaluable blood and urine samples. It was important to know what type of blood tube was required for the blood draw, where to draw the blood, and how to properly process and store the samples.

Access types. It was important for study coordinators to recognize signs of poor clearance, such as access problems, low blood flow, or insufficient dialyzer clearance. If the expected dialysis dose was much higher than the observed, a recirculation test was ordered. Recirculation tests were performed routinely to ensure that the blood was flowing smoothly from the subject’s access through the dialyzer. Although the protocol and manual of operations dictated how to conduct a recirculation test, a dietitian may not have been familiar with some of the new terminology involving the intricacies of the dialysis machine and/or the type of access.

Dialyzers. Because HEMO Study targeted two different levels of dialysis dose, knowledge about different dialyzer clearances for removal of urea and other substances was essential for dietitians who functioned as study coordinators.

Dialysis machines. Dialysis machines give vital information about actual treatment time. If an interruption occurred during the treatment, the machine would alarm and the treatment clock would stop. Although much of this was covered in HEMO training, it was extremely useful for study coordinators to know how to interpret the alarms and readings on each specific machine.

Arterial and venous pressure alarms on the dialysis machine alerted the coordinator that there could be a problem with the patient’s access. For example, very low arterial pressures can signify that the blood is having a problem being pulled from the access, while elevated venous pressures may indicate that the blood is returning to the body with some resistance.^12,13

Dietitian training
Dietitians have a unique educational background; every registered dietitian (RD) needs at least a bachelor’s degree from a university approved by the Commission on Accreditation for Dietetic Education (CADE) from the American Dietetic Association (ADA). Basic course work includes many of the same courses required of other allied health professionals such as anatomy, physiology, microbiology, chemistry, and biochemistry. College coursework also includes food and nutrition sciences, food service, systems management, computer science, business, economics, culinary arts, and sociology.

In addition, a person must also complete a minimum of 900 credit hours in a CADE-accredited or -approved supervised internship at a health care facility, community agency, or food service corporation and pass a national exam to become a registered dietitian. Several states also require that dietitians be licensed to practice, especially in a hospital or a clinic setting. Similar to other health professionals, dietitians are required to maintain a minimum of 75 hours of continuing education every five years to maintain their registration status.

Most dietitians work in hospitals or clinics, have a strong medical background, and are an integral part of the medical team. Many dietitians also hold graduate degrees in areas such as nutrition, exercise science, public health, or business administration—or more specifically, health administration. Others are certified in specialized areas such as pediatric or renal nutrition, nutrition support, or diabetic education.14 Because dietitians have a strong medical background they can also participate in nonnutrition educational programs and certifications such as phlebotomy, CPR, and investigator training programs, if necessary. The potential opportunities are endless.

Benefits of RD study coordinators
The HEMO Study was successful in adhering to the randomized interventions. Because nearly half of the coordinators were dietitians, this demonstrated that an RD was able to function skillfully in the role of study coordinator. The benefit of having a registered dietitian as a coordinator, in addition to the HEMO Study dietitian, helped in recruitment, time management, adherence to the randomized interventions, and interactions with the subjects and staff. A strong medical background in the health sciences, along with clinical expertise, enabled dietitians to overcome the challenges faced as HEMO Study coordinators. Their diverse backgrounds make registered dietitians excellent candidates for the role of study coordinator in clinical research trials.

References:
1. S. Pelke, D. Easa, “The role of the clinical research coordinator in multicenter clinical trials,” Journal of Obstetric, Gynecologic, and Neonatal Nursing, 26 (3) 279–85 (1997).

2. P. Di Giulio, C. Arrigo, H. Gall, C. Molin, R. Nieweg, B. Strohbucker, “Expanding the role of the nurse in clinical trials: the nursing summaries,” Cancer Nursing 19 (5) 343–347 (1996).

3. J. Wozniak-Petrofsky, “The nurse’s role as investigation coordinator in a drug research study” Urologic Nursing Journal, 11 (1) 21–23 (1991).

4. F.A. Gotch , J.A. Sargent. “A mechanistic analysis of the National Cooperative Dialysis Study (NCDS),” Kidney International, 28 (3) 526–534 (1985).

5. P.E. Watson, I.D. Watson, R.D. Batt. “Total body water volumes for adult males and females estimated from simple anthropometric measurements,” American Journal of Clinical Nutrition, 33 (1) 27–39 (1980).

6. S. Ahmad, J.J. Cole, “Lower morbidity associated with higher Kt/V in stable hemodialysis patients,” Journal of American Society of Nephrology, 1:346 (1990).

7. A.J. Collins, J.Z. Ma, A. Umen, P. Keshaviah, “Urea index and other predictors of hemodialysis patient survival,” American Journal of Kidney Diseases, 23 (2) 272-282 (1994).

8. R.M. Hakim, J. Breyer, N. Ismail, and G. Schulaman. “Effects of dose of dialysis on morbidity and mortality,” American Journal of Kidney Diseases, (23) 661-669 (1994).

9. W.F. Owens Jr., N.L. Lew, Y. Liu, E.G. Lowrie, J.M. Lazarus. “The urea reduction ratio and serum albumin concentration as predictors of mortality in patients undergoing hemodialysis,” New England Journal of Medicine, 329 (14) 1001–1006 (1993).

10. G. Eknoyan, A.S. Levey, G.J. Beck, L.Y. Agodoa, J.T. Daugirdas, J.W. Kusek, N.W. Levin, G. Schulman for the HEMO Study Group. The Hemodialysis (HEMO) Study: Rationale for selection of interventions,” Seminars in Dialysis, (9) 24–33 (1996).

11. J. Leung, J. Dwyer, J. Miller, S.W. Patrick, M. Rocco, L. Uhlin, and the HEMO Study Group, “The role of the dietitian in a multi-center clinical trial of dialysis therapy: the Hemodialysis (HEMO) Study,” Journal of Renal Nutrition, (11) 10–108 (2001).

12. E.F. Ravenscroft, G. Ganz, “Hemodialysis vascular access monitoring for stenosis,” Canadian Association of Nephrology Nurses and Technicians Journal, 9 (2) 16–20 (1999).

13. J.Y. Lio, S.S. Chiang, C.H. Chang, H.D. Hua, H.Y. Chou, J.J. Cheng. “The efficacy of percutaneous transluminal angioplasty in the treatment of failing vascular access in chronic hemodialysis patients,” Zhonghua Yi Xue Za Zhi (Taipei), 58 (5) 335–340 (1996).

14. The American Dietetic Association. www.eatright.org.