Routine monthly blood testing for prevalent patients on hemodialysis (HD) is not associated with a lower risk of death, hyperkalemia, cardiovascular (CV) events, or hospitalization compared with blood testing every 6 weeks, according to a new study.

Among incident patients on HD, monthly testing was associated with an increased risk of hyperkalemia, CV events, and hospitalization compared with testing every 6 weeks.

“Given the health resource implications, the frequency of routine blood sampling in HD recipients deserves careful reassessment,” a research team led by Ron Wald, MDCM, MPH, of St. Michael’s Hospital in Toronto and the University of Toronto, concluded.

The study included 7454 prevalent patients and 10,666 incident patients on HD. The prevalent cohort included 5335 patients who had monthly testing and 2119 who underwent testing every 6 weeks. The incident cohort included 7752 patients who underwent monthly testing and 2914 who had testing every 6 weeks.

In both cohorts, monthly testing was not associated with a lower risk for all-cause mortality compared with testing every 6 weeks, Dr Wald and his colleagues reported in the American Journal of Kidney Diseases. In the prevalent cohort, monthly testing also was not associated with a lower risk of hyperkalemia episodes, CV events, and all-cause hospitalization. In the incident cohort, monthly testing was associated with a 20% increased risk of hyperkalemia episodes, an 18% increased risk of CV events, and 11% increased risk of all-cause hospitalization compared with testing every 6 weeks.

“Our findings do not allow us to recommend an optimal frequency for routine blood testing that balances patient safety and resource consumption,” the authors wrote. “We are also unable to make a definitive statement about whether testing every 6 weeks provides noninferior outcomes as compared to monthly testing.”

Reference

Thomas A, Silver SA, Perl J, et al. The frequency of routine blood sampling and patient outcomes among maintenance hemodialysis patients [published online November 12, 2019]. Am J Kidney Dis. doi: 10.1053/j.ajkd.2019.08.016