Does stage-3 chronic kidney disease matter? A systematic literature review

Background

Stage-3 chronic kidney disease (CKD) is the first stage that is identifiable from a blood test alone. In the UK, it accounts for the majority of people on primary care CKD registers. It also represents a group of People who, in the past, would have gone unnoticed clinically. In order to support patients and plan services, the natural history of stage-3 CKD is important.

Aim

To systematically review the natural history of stage-3 CKD in order to describe all cause mortality, cardiovascular morbidity and mortality, and renal outcomes.

Design of study

Systematic review of the literature.

Method

MEDLINE and Embase databases were searched from 1998 to February 2009. Systematic reviews and cohort studies that included adults with stage-3 CKD were considered eligible. Studies were appraised and data extracted by one reviewer and checked by a second.

Results

Thirteen studies were identified including a total of 728 328 people. The all-cause mortality rate varied from 6% in 3 years to 51% in 10 years and was higher in stage-3B CKD (4.8 per 100 person-years) than stage-3A CKD (1.1 per 100 person-years). The relative risk of mortality (all-cause mortality or cardiovascular disease [CVD] mortality) was higher in stage-3 CKD compared with no CKD, but the increase was small for those with stage-3A CKD (hazard ratio [HR] 1.2-1.7) and greater in stage 3B (HR 1.8-3.3). End-stage renal disease was rare (4% in 10 years) and renal progression was evident in <20% of patients after 5 years.

Conclusions

For patients with stage-3 CKD, risk of mortality was higher than for those without CKD, but the risk of progression was low. CKD registers provide an opportunity for GPs to assess the risk of patients developing CVD.