Long term outcome of severe anaemia in Malawian children

Abstract

Background: Severe anaemia is a common, frequently fatal, condition in African children admitted to hospital, but its long term outcome is unknown. Early reports that survivors may be at risk of additional late morbidity and mortality may have significant implications for child survival in Africa. We assessed the short and long term outcome of severe anaemia in Malawian children and identified potential risk factors for death and further severe anaemia.

Methodology and findings: For 18 months, we followed up children (6-60 months old) presenting to hospital with severe anaemia (haemoglobin <or=5 g/dl) and their hospital and community controls with the aim to compare all cause mortality and severe anaemia recurrence rates between the groups, and to identify risk factors for these adverse outcomes. A total of 377 cases, 377 hospital controls and 380 community controls were recruited. Among cases, the in-hospital mortality was 6.4% and post-discharge all cause mortality was 12.6%, which was significantly greater than in hospital controls (2.9%) or community controls (1.4%) (Log rank test, p<0.001). The incidence of recurrence of severe anaemia among the cases was 0.102 per child-year (95% Confidence Interval 0.075-0.138), and was significantly higher than the 0.007 per child-year (95% CI 0.003-0.015) in the combined controls (p<0.0001). HIV was the most important risk factor both for post-discharge mortality (Hazard Ratio 10.5, 95% CI 4.0-27.2) and for recurrence of severe anaemia (HR 5.6, 95% CI 1.6-20.1).

Conclusions: Severe anaemia carries a high 'hidden' morbidity and mortality occurring in the months after initial diagnosis and treatment. Because severe anaemia is very common, this is likely to contribute importantly to overall under-five mortality. If not adequately addressed, severe anaemia may be an obstacle to achievement of the Millennium development goal No.4 on child survival. Strategies to diagnose and properly treat HIV infected children early most likely will reduce the high post-discharge mortality in severe anaemia.

Figure 1. Survival curve showing the time to post-discharge death and the events versus number at risk of severely anaemic children (cases) and hospital and community controls during the follow-up period.

Figure 2. Unadjusted (in black) and adjusted (in red) Hazard Ratios of main risk factors for post-discharge all cause mortality among severely anaemic children (cases).

Figure 3. Survival curve showing the time to first severe anaemia episode and the events versus number at risk of severely anaemic children (cases) and hospital and community controls during the follow-up period.