Screening for childhood anaemia using copper sulphate densitometry.

OBJECTIVE To evaluate copper sulphate densitometry to screen for childhood anaemia in a primary care setting, with a view to identifying children requiring definitive diagnostic testing and treatment. DESIGN A cross-sectional screening study. Results of densitometry with a copper sulphate solution of specific gravity (SG) 1.048, corresponding to a haemoglobin (Hb) concentration of 10 g/dl, were compared with laboratory Hb determination. SETTING Outpatient department of Pretoria Academic Hospital (73 children) and a local crèche (27 children). SUBJECTS One hundred consecutive children, aged between 6 months and 6 years, with informed written consent by parents. OUTCOME MEASURE(S) Accuracy of copper sulphate densitometry in screening for Hb concentration below 10 g/dl in terms of sensitivity, specificity, positive and negative predictive values, as well as likelihood ratio. RESULTS The prevalence of anaemia (Hb < 10 g/dl) was 17% (95% confidence interval (CI) 10.2; 25.8). Copper sulphate densitometry had a sensitivity of 88.2% (95% CI 62.3; 97.9), a specificity of 89.2% (95% CI 79.9; 94.6), a positive predictive value of 62.5% (95% CI 40.8; 80.5) and a negative predictive value of 97.4% (95% CI 90.0; 99.5) in screening for anaemia. The likelihood ratio of a positive screening test was 8.17. CONCLUSIONS Copper sulphate densitometry was accurate in screening for childhood anaemia.