Health-related quality of life and symptom burden in patients on haemodialysis

Abstract

Background: Patients on haemodialysis (HD) generally experience poor health-related quality of life (HRQoL) and a broad range of physical and mental symptoms, but it is unknown whether this differs between younger and older patients. We aimed to describe the trajectories of HRQoL and symptom burden of patients <70 and ≥70 years old and to assess the impact of symptom burden on HRQoL.

Methods: In incident Dutch HD patients, HRQoL and symptoms were measured with the 12-item Short Form Health Survey and Dialysis Symptom Index. We used linear mixed models for examining the trajectories of HRQoL and symptom burden during the first year of dialysis and linear regression for the impact of symptom burden on HRQoL.

Results: In 774 patients, the trajectories of physical HRQoL, mental HRQoL and symptom burden were stable during the first year of dialysis. Compared with patients <70 years of age, patients ≥70 years reported similar physical HRQoL {mean difference -0.61 [95% confidence interval (CI) -1.86-0.63]}, better mental HRQoL [1.77 (95% CI 0.54-3.01)] and lower symptom burden [-2.38 (95% CI -5.08-0.32)]. With increasing symptom burden, physical HRQoL declined more in older than in younger patients (β = -0.287 versus -0.189, respectively; P-value for interaction = .007). For mental HRQoL, this decrease was similar in both age groups (β = -0.295 versus -0.288, P = .847).

Conclusion: Older HD patients generally experience a better mental HRQoL and a (non-statistically significant) lower symptom burden compared with younger patients. Their physical HRQoL declines more rapidly with increasing symptom burden.

Keywords: ageing; dialysis; end-stage renal disease; kidney failure; patient-reported outcomes.

Figure 1:

Longitudinal assessment of physical and mental HRQoL. Graphs show the estimated mean scores of the PCS score (left) and the MCS score (right) of the SF-12 with error bars indicating the 95% CIs. Mean differences indicate the mean difference over the 1-year observation period, using patients <70 years old as the reference and patients ≥70 years old as the comparison. Note that scores range from 0 to 100 and higher scores indicate better HRQoL. Mean scores and differences are estimated using linear mixed models.

Figure 2:

Prevalence of all 30 symptoms at dialysis initiation among younger (blue) and older (orange) patients, in order of descending prevalence. Statistically significant differences between age groups are shown with their P-values.

Figure 3:

Longitudinal assessment of overall symptom burden. Graphs show the estimated mean scores of the total symptom burden score, measured using the 30-item DSI, with error bars indicating the 95% CIs. Mean difference indicates the mean difference over the 1-year observation period, using patients <70 years old as the reference and patients ≥70 years old as the comparison. Note that scores range from 0 to 150, with higher scores indicating more symptoms and/or higher experienced severity of symptoms. Mean scores and differences are estimated using linear mixed models.

Figure 4:

Scatterplot showing the association of overall symptom burden with physical HRQoL (left) and mental HRQoL (right), measured at the start of HD. Note that symptom burden scores range from 0 to 150, with higher scores indicating the presence of more symptoms and/or a higher severity per symptom. HRQoL scores range from 0 to 100, with higher scores indicating better QoL.

Figure 5:

Results of the main and sensitivity analyses. The x-axis shows mean differences of the longitudinal analyses and their 95% CIs, using patients <70 years old as the reference and ≥70 years old as the comparison. Note that higher scores for HRQoL and lower scores for symptom burden indicate better performance. The result (M) depicts the study's main results (number of patients included in the analysis, N = 774), (1) the first sensitivity analysis with exclusion of patients who died within the first year (n = 732), (2) the second sensitivity analysis with exclusion of patients who did not complete their first year, i.e. due to death, kidney transplantation, recovery of kidney function, withdrawal of informed consent or loss to follow-up (n = 622), (3) the third sensitivity analysis with inclusion of complete cases only (n = 659 for HRQoL, n = 628 for symptom burden) and (4) the fourth sensitivity analysis, comparing patients <50 years of age (reference) with patients ≥80 years of age (n = 215).