Fernando Valderrábano Quintana
Hospital General Universitario Gregorio Marańón,
Madrid, Spain.

In evaluating outcomes in end-stage renal disease (ESRD), as well as in other chronic diseases, QoL has become as important as morbidity and mortality. It is also a valuable parameter in the evaluation of treatment effectiveness and cost-profit analysis. QoL according to the WHO definition is not only the absence of disease, but the presence of physical, mental and social well-being.

There are different instruments to analyze the patient perception of the physical, psychological and social domains of health. These instruments may be non-specific or disease-specific. Non-specific instruments have been widely used in evaluating QoL in different chronic diseases as well as in ESRD, such as the Sickness Impact Profile (SIP) and more recently the SF-36. The Kidney Disease Quality of Life (KDQOL) test and its short form KDQOL-SF are specific tests developed for ESRD patients.

Several factors influence QoL in ESRD patients. After the introduction of epoetin treatment, several studies demonstrated a significant improvement in QoL of dialysis and pre-dialysis patients. The hemoglobin level achieved after epoetin therapy has a close relationship to QoL scores. The higher the hemoglobin level, the better the QoL. Other factors related to better QoL are the socio-economic level and the level of education. However, older age, comorbidity, diabetes and female sex are related to a worse QoL.

In pre-dialysis patients, epoetin treatment significantly improves QoL, allowing the patient to maintain a situation of well-being until starting dialysis. It has been shown that QoL in pre-dialysis patients deteriorates in relation to the decrease of GFR, and a worse QoL is also related to a late referral of the patient to the nephrologist. Older age, co-morbidity, female sex, poor educational level and unemployment are other factors with a negative influence in QoL. Recent studies show that QoL is a prognostic factor of survival. ESRD patients with low QoL have a higher mortality than those perceiving a good QoL.

Early treatment of anemia in ESRD patients is the best way to maintain an adequate QoL in the pre-dialysis and dialysis phase, and is associated to a good survival rate.