Rationale for Guideline Hemoglobin Targets

Hemoglobin Targets

Contribution from the Caring for Australians with Renal Impairment (CARI) Guidelines Commitee

The 2006 CARI guideline on Biochemical and Haematological Targets recommends:

  • Haemoglobin concentration for patients with proven or likely cardiovascular disease should not exceed 120 gm/L.

Rationale:
The main reason for the differences between the CARI guidelines relating to Hb targets and those of other renal guidelines bodies relate to the evidence required to support the derivation of a guideline. CARI requires either a meta-analysis or a well designed RCT (ie: Level I or Level II evidence) to support a ‘Guideline’ and, where the available evidence is of a lower level (ie Level III or IV), makes ‘Suggestions for Clinical Care’. Other renal guideline bodies do not use this policy, explaining much of the disparity.

In relation to Hb targets in patients with kidney disease, the only evidence that was of Level I or II (in the opinion of the reviewers) was that relating to the probable risk of Hb concentrations >120 g/L in patients with proven or likely significant cardiovascular disease. As such, this is the only ‘Guideline’. The evidence for quality of life and other improvements with higher Hb concentrations did not show a survival advantage and was not of a level that justified a ‘Guideline’ recommendation for higher Hb targets in any subpopulation of patients with renal disease.

However, the ‘Suggestions for Clinical Care’ based upon lower levels of evidence are largely consistent with the ‘Guidelines’ from the other bodies (KDOQI, CSN and EBPG). The UK Renal Association guidelines do set a lower minimum target level of Hb of 100 g/L that is different from the other groups because of inadequate evidence for the more widely supported level of 110 g/L. The fact that this differs from the CARI Guidelines likely reflects a different interpretation of the less compelling evidence.

Prepared on behalf of CARI by Lawrie McMahon and Carol Pollock, CARI Biochemical and Haematological Targets Guidelines Working Group