Unclear data were clari ed by contacting the author of the study report, and any relevant data obtained in this manner were included. The ERT designed data extraction forms to capture data on study design, study participant characteristics, intervention and comparator characteristics, and critical and important outcomes. Any differences in extraction between mem- bers of the ERT were resolved through discussion. A third reviewer was included if consensus could not be achieved. Critical appraisal of studies. The majority of reviews undertaken were intervention reviews that included RCTs. For these reviews, the Cochrane Risk of Bias tool was used to assess individual study limitations based on the following items383 :  Was there adequate sequence generation (selection bias)?  Was allocation adequately concealed (selection bias)?  Was knowledge of the allocated interventions adequately pre- vented during the study (detection bias)?  Participants and personnel (performance bias)  Outcome assessors (detection bias)  Were incomplete outcome data adequately addressed (attrition bias)?  Are reports of the study free of suggestion of selective outcome reporting (reporting bias)?  Was the study apparently free of other problems that could put it at risk of bias? For some topics, for which there were no RCTs in the CKD population, the ERT conducted reviews of existing systematic re- views. AMSTAR 2 was used to critically appraise systematic re- For systematic reviews of diagnostic test accuracy studies, the QUADAS-2 tool was used to assess study limitations.386 All critical appraisal was conducted independently by 2 ERT members, with disagreements regarding the risk of bias adjudications resolved by consultation with a third review author. Evidence synthesis and meta-analysis. Measures of treatment effect. 