Variables which influence the health related quality of life (HRQOL) of patients on renal replacement therapy (RRT)

The aim of this study was to investigate the sociodemographic and clinical variables which influence health-relate quality of life (HRQOL) of patients on renal replacement therapy (RRT). A cross-sectional study was carried ou t with a sample including all patients an hemodialysis (n = 170) and transp lant patients (n = 210) of our region. The HRQOL assessment instruments use d in this study were: the Spanish versions of the sickness impact profile ( SIP) and the SF-36 health survey (SF-36). Sociodemographic and clinical dat a (including age at start of RRT, age at the interview gender, hospital, so cioeconomic level, educational level, living conditions, inclusion in trans plant waiting list, renal disease diagnosis, time in any RRT; hemoglobin, h ematocrit, serum urea, creatinine, proteins and albumin, hospital admission s and length of hospital stay during last year), a comorbidity index and th e Karnofsky performance scale score step. To investigate which studied variables had independent influence over the H RQOL measures, logistic regression method was employed in the case of the S F-36, and multiple regression, in the case of the SIP. A model was adjusted step by step in each RRT method (hemodialysis and transplantation) for eac h dimension of the PCE (physical dimension, pchosocial dimension and fetal score), and for each component summary score of the SF-36 (physical and men tal component summary). In patients on hemodialysis, variables associated with better HRQOL were: h igher age, female gender, higher educational level, and better functional s tatus; and variables associated with worse HRQOL were: higher number of hos pital admissions, and higher comorbidity index. In transplant patients, var iables associated with better HRQOL were: higher age and higher functional status; and variables associated with worse HRQOL were: longer time on dial ysis before transplant, longer time with functioning transplant, and higher comorbidity index. Despite the independent influence on the HRQOL demonstr ated for some of the studied variables, it seems that HRQOL assessment inst ruments scores may mainly depend on other non-studied variables, and it may be that these instruments evaluate other aspects of the patients which hav e not been taken into account until now.