Higher Symptom Frequency and Severity After the Long Interdialytic Interval in Patients on Maintenance Intermittent Hemodialysis

INTRODUCTION: Patients on intermittent hemodialysis (HD) have a high symptom burden. Though studies report higher hospitalizations and mortality after the long interdialytic interval, whether symptoms vary based on the interdialytic interval is unclear. METHODS: This is a prospective observational study of patients over the age of 18 who received in-center HD. Patients were surveyed on the presence and severity of 20 different symptoms at the end of 12 HD sessions. Wilcoxon signed-rank test was used for comparison of severity for each symptom by the interval. Multivariable generalized estimating equation with Poisson regression by repeated measure method was used to determine the association of interdialytic interval and symptom frequency while adjusting for potential confounders. RESULTS: From the 97 patients enrolled, the most common symptoms were fatigue (60.8%), cramping (58.8%), and dry skin (52.6%). There was large variability in the frequency of symptoms, ranging 0% to 8% of treatments. The most severe symptoms were bone pain (mean severity score 2.2±0.9) and diarrhea (mean severity score 2.2±0.7). Eight of the 20 symptoms were significantly more common after the long interdialytic interval including fatigue (22% vs. 15%, P < 0.001) and cramping (21% vs. 16%, P = 0.003). The long interval had a 37% higher incidence rate for symptoms compared to the short interval even after adjustment. Results were similar across genders. CONCLUSION: Symptoms are more common after the long interdialytic interval. Clinical assessment and research evaluating patient symptoms need to be cognizant of when patients are surveyed or include the length of interdialytic interval as a confounding variable.