Background
Prospective studies of the effects of long-standing haemodialysis (HD) on quality of life (QOL) show conflicting results. We investigated how QOL progresses over time in HD patients and what factors are associated with this evolution.
Methods
We included chronic HD patients over the age of 18 from a single unit, who had never had transplants and survived the first 3 months of treatment. Ninety-two patients were followed for 2 years, and the SF-36 questionnaire was administered at baseline and every 12 months. Comorbidity was assessed at baseline using the Khan index. We used repeated-measures analysis of variance to establish changes in QOL and stepwise linear regression to identify continuous variables that could explain variations of SF-36 sub-scales. Then, according to the rate of change of QOL, we stratified the sample to identify the association between categorical variables and the evolution of QOL.
Results
There was a higher (better) final score related to social functioning (63.8 vs. 75.0; P < 0.01), role-emotional (39.7 vs. 63.1; P < 0.01) and mental health (63.1 vs. 69.0; P < 0.01) in the all-sample analysis, and in two other domains in low-comorbidity patients: physical functioning (56.7 vs. 63.5; P = 0.01) and bodily pain (56.7 vs. 66.5; P < 0.01). Creatinine (r = 0.09; P = 0.04) and age (r = −0.03; P = 0.02) were correlated with the evolution of general health and bodily pain, respectively. There were more women who presented deteriorated physical function than men (50.0 vs. 21.2%; P < 0.01).
Conclusions
There was improvement of QOL mental domains over time. However, the physical aspects improved only in low-comorbidity patients. More women than men worsened regarding physical functioning.