AmJ Kid Dis 2010;55:800-812
This is a (self) invited commentary written by eight Canadian Nephrologists. The CSN leadership sought interest from its membership on participation in the commentary process. It is unclear how the final group was chosen. The commentators come from three of the provinces (Alberta , Ontario  and Nova Scotia ). There is a mixture in the group between those have been know to speak forcefully on the need for an approach which relies very stringently on high grade evidence and which gives a major consideration to cost, and those who will accept lower grades of evidence, and who hold patient advocacy above cost containment. The final draft was sent out for peer review to select members of the CSN rather than to the membership in general, or, necessarily, to those who had expressed interest.
Outline of Review
The authors praise the KDIGO group on the quality of their review of the field of mineral metabolism, but justify the need for the commentary by stating that “local factors require consideration when making recommendations to guide care.” This allows the authors the luxury of suggesting that the goal of any guideline should be to recommend the best available care dictated by local factors, rather than the best care available universally.
The commentary is confined to those areas of the KDIGO report with which the authors have considerable experience - that is to say adult non-dialysis and dialysis CKD patients, excluding those with functioning allografts.
The authors state that their main aim is to comment on recommendations which are based on level 1 evidence in the KDIGO guideline.
In terms of patient investigation, the commentary then provides a Canadian perspective on such recommendations as the timing of initiation and frequency of blood test measurements, the use of bone biopsy, bone densitometry, and methods to identify vascular and valvular calcification. The commentators point out some self-evident truths, such as the fact that the majority of Canadians have low normal or low vitamin D levels, so that treatment with cholecalciferol without measurement of vitamin D levels is reasonable. They note that bone biopsies are not done routinely in Canada, and that many women reach stage 4 CKD (when nephrology referral is suggested), already on effective treatment for osteoporosis (including bisphosphonates) having been screened and followed by BMD. Indeed they bow to Osteoporosis Canada for recommendations in this regard.
In terms of phosphate and parathyroid hormone management, the lack of patient level outcomes causes the commentators to recommend inexpensive over expensive phosphate binders, and surgery over medical management respectively. They do note that safety data for the inexpensive binders are lacking, and that a danger signal has been raised for calcium-containing binders, but cost seem the over-riding priority here. In terms of parathyroidectomy, again the cost savings appear to over-ride the early mortality risk of surgery, the authors presumably taking comfort in the data that show a late survival advantage to patients who have a parathyroidectomy.
Given the make-up of the group, the article contains no surprises. It essentially restates the Canadian position as we have it in many, but not all of the provinces. While in some jurisdictions, more liberal prescribing is possible, in many, choices for mineral metabolism control are few.
The strength of this paper is in the conclusion section which calls on the Nephrology community to organize itself in such a way as to provide the answers that the evidence-based medicine supporters demand, and that our patients deserve.
Impact on Practice
This review will have little impact on the current management of mineral metabolism in Canada.