G6PD and G6PD deficiency: The proportion of patients whose PCV fell below 20 and 25% was also significantly higher in the CD+A G6PD (A-) group when compared with all other groups; when all other patients were combined into one group, the odds of a severe reduction in the haematocrit (defined as the proportion of patients whose PCV fell below 20%) was 9 times more likely to occur in patients with G6PD deficiency recipients of CD+A (OR = 9.2, 95% CI 2.8 to 30.2, p<0.001).