Reproducibility and validity of portable haemoglobinometer for thediagnosis of anaemia in children under the age of 5 years

Abstract

Portable haemoglobinometers have been used in order to estimate the prevalence of anaemia in diverse settings. However, few studies have been conductedto evaluate their performance in children of different age groups in distinct epidemiological contexts. To evaluate the reproducibility and reliability of aportable haemoglobinometer for the diagnosis of anaemia in children <5 years Hb was measured in the venous blood of 351 children <5 years by anautomated system (standard method) and in three capillary blood samples, using a portable haemoglobinometer (HemoCue®; test method). The reprodu-cibility of the device and of the test method was evaluated using the intraclass correlation coefficient (ICC) (Hb in its continuous form),κand prevalence-adjusted bias-adjustedκ(PABAK) (categorised variable: anaemia: yes/no). For test method validation, Bland–Altman analyses were performed andsensitivity, specificity, accuracy rate, positive predictive value (PPV) and negative predictive values (NPV) were calculated. The haemoglobinometer pre-sented good device reproducibility (ICC = 0·79) and reasonable method reproducibility (puncture, collection and reading) (ICC = 0·71). Superficial andfair agreement (κ) and good agreement (PABAK) were observed among the diagnoses obtained through the test method. The prevalence of anaemiawas 19·1 and 19·7 % using the standard and the test method, respectively, with no statistically significant differences. The test method presented higherspecificity (87·7 %) and NPV (88·3 %) than sensitivity (50·7 %) and PPV (49·3 %), and intermediary accuracy rate (57·8 %). HemoCue®showed gooddevice reproducibility and reasonable method reproducibility, as well as good performance in estimating the prevalence of anaemia. Nevertheless,it showeda fair reliability and low individual diagnostic accuracy