Abstract:
Background: Severe anaemia in children requiring hospital admission is a
major public health problem in malaria-endemic Africa. Affordable methods for
the assessment of haemoglobin have not been validated against gold standard
measures for identifying those with severe anaemia requiring a blood
transfusion, despite this resource being in short supply.
Methods: We conducted a prospective descriptive study of hospitalized
children aged 2 months – 12 years at Mbale and Soroti Regional Referral
Hospitals, assessed to have pallor at triage by a nurse and two clinicians.
Haemoglobin levels were measured using the HemoCue Hb 301 system
(gold standard); the Haemoglobin Colour Scale; calorimetric and Sahli’s
methods. We report clinical assessments of the degree of pallor, clinicians’
intention to transfuse, inter-observer agreement, limits of agreement using the
Bland-Altman method, and the sensitivity and specificity of each method in
comparison to HemoCue
Results: We recruited 322 children assessed by the admitting nurse as having
severe (164; 51.0%), moderate (99; 30.7%) or mild (57; 17.7%) pallor.
Agreement between the clinicians and the nurse were good: Clinician A
Kappa=0.68 (0.60–0.76) and Clinician B Kappa=0.62 (0.53–0.71) respectively (
P<0.0001 for both). The nurse, clinicians A and B indicated that of 94/116
(81.0%), 83/121 (68.6%) and 93/120 (77.5%) respectively required transfusion.
HemoCue readings indicated anaemia as mild (Hb10.0–11.9g/dl) in 8/292
(2.7%), moderate (Hb5.0–9.9g/dl) in 132/292 (45.2%) and severe (Hb<5.0g/dl)
in 152/292 (52.1%). Comparing to HemoCue® the Sahli’s method performed best in estimation of severe anaemia, with sensitivity 84.0% and specificity
87.9% and a Kappa score of 0.70 (0.64–0.80).
Conclusions: Clinical assessment of severe pallor results has a low specificity
for the diagnosis of severe anaemia. To target blood transfusion Hb
measurement by either Hemocue® or Sahli’s method for the cost of USD 4 or
and USD 0.25 per test, respectively would be more cost-effective.
