The relative risk of death in the ICU was associated with severe anaemia post SAH, even after adjustment for severity of bleed and WFNS grade (RR 1.91, 95%CI 0.97-3.64). Univariate survival analysis of the lowest Hb, hypotension with a SBP of 80-100 mmHg, admission WFNS score, and occurrence of hydrocephalus were all statistically significant (Tables 3, 4). This evidence concerns the gene GSTM1 and anemia (phenotype).