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A randomized controlled trial of long term effect of BCM guided fluid management in MHD patients (BOCOMO study): rationales and study design

Li Liu12, Gang Long3, Jianwei Ren4, Jijun Li5, Jinsheng Xu6, Jinghong Lei7, Mao Li8, Moyan Qiu9, Ping Yuan10, Weiming Sun11, Shan Lin12, Wenjun Liu13, Yi Sun14, Yingchun Ma15, Yonghui Mao16, Yulan Shen17 and Li Zuo12*

Author affiliations

1 Institute of Nephrology, Peking University First Hospital, Beijing, China

2 Renal Division, Peking University First Hospital, Beijing, China

3 Renal Department, Tianjin Union Medicine Center, Tianjin, China

4 Renal Department, Aviation General Hospital, Beijing, China

5 Renal Department, PLA General Hospital First Hospital, Beijing, China

6 Renal Department, Hebei Medical University Forth Hospital, Hebei, China

7 Renal Department, Beijing Aerospace General Hospital, Beijing, China

8 Renal Department, Beijing Puren Hospital, Beijing, China

9 Renal Department, Beijing Wangjing Hospital, Beijing, China

10 Renal Department, Tianjin Third Central Hospital, Tianjin, China

11 Renal Department, Beijing Shijitan Hospital, Beijing, China

12 Renal Department, Tianjin Medical University General Hospital, Tianjin, China

13 Renal Department, Guanganmen Hospital, China Academy of Chinese Medical Sciences, Guanganmen, China

14 Renal Department, Capital University Fuxing Hospital, Beijing, China

15 Renal Department, China Rehabilitation Research Center, Beijing Boai Hospital, Beijing, China

16 Renal Department, Beijing Hospital of Ministry of Health, Beijing, China

17 Renal Department, Miyun Hospital, Beijing, China

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Citation and License

BMC Nephrology 2012, 13:120  doi:10.1186/1471-2369-13-120

Published: 25 September 2012



Bioimpedance analysis (BIA) has been reported as helpful in identifying hypervolemia. Observation data showed that hypervolemic maintenance hemodialysis (MHD) patients identified using BIA methods have higher mortality risk. However, it is not known if BIA-guided fluid management can improve MHD patients’ survival. The objectives of the BOCOMO study are to evaluate the outcome of BIA guided fluid management compared with standard care.


This is a multicenter, prospective, randomized, controlled trial. More than 1300 participants from 16 clinical sites will be included in the study. The enrolment period will last 6 months, and minimum length of follow-up will be 36 months. MHD patients aged between 18 years and 80 years who have been on MHD for at least 3 months and meet eligibility criteria will be invited to participate in the study. Participants will be randomized to BIA arm or control arm in a 1:1 ratio. A portable whole body bioimpedance spectroscopy device (BCM—Fresenius Medical Care D GmbH) will be used for BIA measurement at baseline for both arms of the study. In the BIA arm, additional BCM measurements will be performed every 2 months. The primary intent-to-treat analysis will compare outcomes for a composite endpoint of death, acute myocardial infarction, stroke or incident peripheral arterial occlusive disease between groups. Secondary endpoints will include left ventricular wall thickness, blood pressure, medications, and incidence and length of hospitalization.


Previous results regarding the benefit of strict fluid control are conflicting due to small sample sizes and unstable dry weight estimating methods. To our knowledge this is the first large-scale, multicentre, prospective, randomized controlled trial to assess whether BIS-guided volume management improves outcomes of MHD patients. The endpoints of the BOCOMO study are of utmost importance to health care providers. In order to obtain that aim, the study was designed with very careful important considerations related to the endpoints, sample size, inclusion criteria, exclusion criteria and so on. For example, annual mortality of Beijing MHD patients was around 10%. To reach statistical significance, the sample size will be very large. By using composite endpoint, the sample size becomes reasonable and feasible. Limiting inclusion to patients with urine volume less than 800 ml/day the day before dialysis session will limit confounding due to residual renal function effects on the measured parameters. Patients who had received BIS measurement within 3 months prior to enrolment are excluded as data from such measurements might lead to protocol violation. Although not all patients enrolled will be incident patients, we will record the vintage of dialysis in the multivariable analysis.

Trial registration

Current Controlled Trials NCT01509937

Hemodialysis; Bioimpedance; Dry weight; Body composition monitor; Randomized controlled trial