Table 1.

A priori criteria for classifying cause of death

Category	Category description	Clinical criteria
1	Pure vivax malaria the primary cause of death	Potential mechanisms include: coma, extreme anaemia (haemoglobin <3 g/dL), respiratory distress not associated with evidence of sepsisa, acidosis if associated with severe anaemia or splenic rupture
2	Pure vivax malaria likely to have been a major contributor to death	Alternative cause(s) more likely to have led to death but vivax malaria a major contributor through one of the following mechanisms: haemoglobin <7 g/dL, respiratory distress not associated with evidence of bacterial sepsisa, acidosis if associated with haemoglobin <7 g/dL, splenic rupture, decreased consciousness or malnutritionb with two or more documented episodes of vivax malaria in the last year
3	Pure vivax malaria likely to have been a minor contributor to death	Alternative cause(s) more likely to have led to death but vivax malaria a minor contributor through one of the following mechanisms: fever, tachycardia or anaemia (haemoglobin between 7 g/dL and the lower limit of normal)
4	Pure vivax malaria unlikely to have contributed to death	No clear direct pathophysiological mechanism by which vivax malaria could have exacerbated or contributed to the primary cause(s) of death

^aSepsis conservatively attributed to bacterial co-infection. Evidence of sepsis defined as consolidation on chest X-ray or any deviation in white cell count from the age-adjusted normal range (birth; 20,000-40,000/mm³, 1 week; 5,000-21,000/mm³, 2 weeks; 5,000-20,000/mm³, 3 months to 12 months; 5,000-15,000/mm³, 1 year to 5 years; 5,000-12,000/mm³, greater than 5 years; 4,000-10,000/mm³).

^bMalnutrition defined as documented malnutrition in the notes or a weight-for-age Z-score less than -3, according to the WHO Child Growth Standards [19].