Table 1. Pathophysiological mechanisms in Malawian children with severe anaemia.

Mechanism	Definitions used	Prevalence (n) #
Red Cell Production Failure (RCPF)	Whole blood haemoglobin <3.2 mMol/L (5.0 g/dL) and Reticulcytes <50,000/uL †	48.1% (113/235)
Haemolysis	Plasma haemoglobin >0.10 mMol/L (0.15 g/dl) and/or Bilirubin >16.9 mmol/L	21.7% (51/235)
Blood loss	UT: Urine dip-stick >1+ for erythrocytes and/or GI: Hookworm load >1000 eggs/gram stool *	7.2% (17/235)
Non defined	Not fulfilling any of the above criteria	34.5% (81/235)

GI  =  Gastro-intestinal, UT  =  Urinary Tract.

# Includes patients with a complete dataset only.

3*Gastro-intestinal (GI) blood loss was measured indirectly, using a hookworm infection as a substitute marker.

^†If a reticulocyte cut-off <150,000/uL is used to define RCPF, 86.4% (203/235) of patients would fall into this category, with a 23.0% (54/235) overlap with haemolysis and blood loss.