Background: Physical (PCS) and mental (MCS) component summary scales of the Short Form 36 (SF-36) health survey are validated measures of quality of life (QOL) and functional status. We sought to evaluate the PCS and MCS in haemodialyis patients as compared to the general population and other chronic diseases.
Methods: A cohort of 134 haemodialysis patients (mean age 60.9+/-14.3 years, males 63.4%, Caucasians 66.4%) was followed from January 1996 to December 1998 (mean follow up 14.5+/-5.7 months). SF-36 questionnaires were administered every 3 months and PCS and MCS were calculated. Results were compared to the general population and other chronic diseases. Correlators of PCS and MCS, change in QOL over time, and the correlators of this change were determined.
Results: Mean PCS was 36.9+/-8.8 and mean MCS was 47+/-10.7. Compared to the general US population, these represent a decline of 8.7+/-0.8 for PCS (P<0.0001) and 2.7+/-0.8 for MCS (P<0.001). PCS and MCS in end-stage renal disease (ESRD) were lower than in most other chronic diseases studied. Univariate correlators of PCS in haemodialysis patients included age, male sex, haematocrit, serum albumin, and severity of comorbid cardiac and pulmonary illnesses. Multivariate analysis demonstrated independent correlators of PCS to be male sex, serum albumin and severity of comorbid cardiac and pulmonary diseases. Univariate as well as multivariate correlators of MCS included: serum albumin, KT/V(urea), and status living alone. A trend analysis revealed that both PCS and MCS tended to decline in the initial months of dialysis but stabilized over time. Status living alone was a significant predictor of improvement in MCS by univariate as well as multivariate analysis.
Conclusions: Self assessed physical and mental health of haemodialysis patients is markedly diminished compared to the general population and other chronic diseases.