GSTM1 and anemia (phenotype): Thus, we feel it would be meaningful to study: A) the quality of anaemia control in dialysed patients in Switzerland; B) if the control of anaemia and its treatment parameters could be maintained over a long period of time, C) if co-morbidities may modulate Hb level and EPO dose, and D) if anaemia management has improved when compared with earlier assessments.