UC Irvine

Background

Previous studies have demonstrated that early pre-end-stage renal disease (ESRD) nephrology care could improve postdialysis prognosis. However, less is known about the specific types of interventions responsible for the improved outcomes. We hypothesized that more frequent predialysis laboratory testing is associated with better postdialysis outcomes in incident ESRD patients.

Methods

In all, 23 089 patients with available outpatient laboratory tests performed during the 2-year predialysis (i.e. prelude) period were identified from a total of 52 172 American veterans with chronic kidney disease (CKD) transitioning to dialysis between October 2007 and September 2011. The associations between the frequency of combined laboratory tests, including serum creatinine, serum potassium and hemoglobin (test trio), with postdialysis mortality and hospitalization were examined in multivariable adjusted Cox and logistic regression models.

Results

When entering the 2-year prelude period, the mean age (Standard Deviation) of the patients was 66.2 (SD 11.3) years and the mean estimated glomerular filtration rate was 46.8 (SD 23.9) mL/min/1.73 m2. In all, 14% of patients had the test trio performed less than twice in 24 months and 8.9% had the trio measured more often than every other month. Over a 2.5-year median postdialysis follow-up period, 15 303 (66.3%) patients died (mortality rate 260/1000 patient-years). The adjusted hazard ratio of all-cause mortality and adjusted odds ratio of the composite of hospitalization or death associated with lab testing done >12/24 months compared with 2-≤4/24 months were 0.68 [95% confidence interval (CI) 0.65-0.73] and 0.70 (95% CI 0.62-0.79), respectively.

Conclusions

More frequent laboratory testing in patients with advanced CKD is associated with better clinical outcomes after dialysis. Further examination in clinical trials is needed before the implementation of more frequent laboratory testing in clinical practice.