The Association Between Intradialytic Symptom Clusters and Recovery Time in Patients Undergoing Maintenance Hemodialysis: An Exploratory Analysis

Background: Individuals receiving hemodialysis often experience concurrent symptoms during treatment and frequently report feeling unwell after dialysis. The degree to which intradialytic symptoms are related, and which specific symptoms may impair health-related quality of life (HRQoL) is uncertain. Objectives: To explore intradialytic symptoms clusters, and the relationship between intradialytic symptom clusters with dialysis treatment recovery time and HRQoL. Design/setting: We conducted a post hoc analysis of a prospective cohort study of 118 prevalent patients receiving hemodialysis in two centers in Calgary, Alberta and Hamilton, Ontario, Canada. Participants: Adults receiving hemodialysis treatment for at least 3 months, not scheduled for a modality change within 6 weeks of study commencement, who could provide informed consent and were able to complete English questionnaires independently or with assistance. Methods: Participants self-reported the presence (1 = none to 5 = very much) of 10 symptoms during each dialysis treatment, the time it took to recover from each treatment, and weekly Kidney Disease Quality of Life 36-Item-Short Form (KDQoL-36) assessments. Principal component analysis identified clusters of intradialytic symptoms. Mixed-effects, ordinal and linear regression examined the association between symptom clusters and recovery time (categorized as 0, >0 to 2, >2 to 6, or >6 hours), and the physical component and mental component scores (PCS and MCS) of the KDQoL-36. Results: One hundred sixteen participants completed 901 intradialytic symptom questionnaires. The most common symptom was lack of energy (56% of treatments). Two intradialytic symptom clusters explained 39% of the total variance of available symptom data. The first cluster included bone or joint pain, muscle cramps, muscle soreness, feeling nervous, and lack of energy. The second cluster included nausea/vomiting, diarrhea and chest pain, and headache. The first cluster (median score: -0.56, 25th to 75th percentile: -1.18 to 0.55) was independently associated with longer recovery time (odds ratio [OR] 1.62 per unit difference in score, 95% confidence interval [CI]: 1.23-2.12) and decreased PCS (-0.72 per unit difference in score, 95% CI: -1.29 to -0.15) and MCS scores (-0.82 per unit difference in score, 95% CI: -1.48 to -0.16), whereas the second cluster was not (OR 1.24, 95% CI: 0.97-1.58; PCS 0.19, 95% CI -0.46 to 0.83; MCS -0.72, 95% CI: -1.50 to 0.06). Limitations: This was an exploratory analysis of a small data set from 2 centers. Further work is needed to externally validate these findings to confirm intradialytic symptom clusters and the generalizability of our findings. Conclusions: Intradialytic symptoms are correlated. The presence of select intradialytic symptoms may prolong the time it takes for a patient to recover from a dialysis treatment and impair HRQoL.