With many things in life – such as exercise, sleep, or practicing for a big event – more is usually better. Many nephrologists have long suspected that “more is better” when it comes to dialysis as well. While the HEMO trial showed no benefit to increasing within-session intensity of thrice-weekly dialysis, several uncontrolled studies have suggested there are benefits to increasing the frequency of dialysis. The data to support the claim that “more frequent is better” has not included a randomized controlled trial – until now.
In this week’s issue of NEJM, Dr. Glenn Chertow and colleagues present the Frequent Hemodialysis Network’s Daily Dialysis trial. This prospective, multicenter, parallel-group clinical trial randomized 245 dialysis-dependent adults to undergo frequent (6 times per week) or standard (3 times per week) in-center hemodialysis for one year. Frequent dialysis was significantly superior on both co-primary outcomes: The composite of death or change in left ventricular mass (“death/LVM”; Hazard ratio 0.61, 95%CI 0.46-0.82), as well as the composite of death or change in RAND Physical Health Composite from the SF-36 (“death/PHC”; HR 0.70, 95%CI 0.53-0.92). Secondary outcomes of hypertension and hyperphosphatemia were also improved, although patients in the frequent hemodialysis arm were more likely to undergo vascular access interventions (HR 1.71, 95%CI 1.08-2.73).
What do these findings mean for patients on dialysis? These results support the conclusion that more frequent in-center dialysis leads to improvement in selected patient outcomes, at least among the patients enrolled in the study. However, patients, providers, and payers are left to answer whether the benefits of more frequent dialysis outweigh the inconvenience, cost, and increase in vascular access interventions that daily in-center hemodialysis entails. Chertow et al. anticipated difficulties in recruiting patients to their study. Did potential study subjects decline enrollment because the burden of more frequent dialysis was unacceptable? Will the benefits gained by doubling the frequency of dialysis be worth the hefty price tag tied to that change? Will the increase in frequency even be feasible with the changes that are about to occur in the funding of dialysis in the United States?
“This randomized trial represents a serious effort to determine the optimal frequency of in-center hemodialysis,” says nephrologist and NEJM deputy editor Dr. Julie Ingelfinger, “but far more data are needed before daily in-center dialysis could become standard of care. Whether the additional benefits from more frequent dialysis outweigh the potential side effects (particularly those that involve hemodialysis access), the inconvenience, and the added cost remains to be determined.”
The trial by Chertow et al adds useful data to the debate about whether more frequent dialysis is better for patients or not. Even if it is superior for specific outcomes, is it the right thing to do for the patient overall? And what implications would daily dialysis have for the organization and affordability of healthcare overall? With more data, more time, and more debate, we might have better answers to these questions – and in that realm, at least, more might be better after all.