Haemoglobin point-of-care testing

Abstract

In this study the suitability of two haemoglobin (Hb) point-of-care testing (POCT) devices namely Diaspect Tm and STAT-Site® M Hgb was assessed. The objectives were to compare performance characteristics of the two devices against standard laboratory testing (Sysmex® XN-9000 Series), and to evaluate the feasibility of introducing this service in community pharmacy practice. In the first part of the study, 72 subjects were recruited from a Health Care Centre. Testing was implemented on patients who were undergoing a routine venous blood test and were suffering from chronic kidney disease (CKD) (n=24), diabetes (n=24) or were otherwise healthy (n=24). Testing involved finger pricking with a lancet and using the second and fourth drop of blood to generate a result using STAT-Site® M Hgb and Diaspect Tm, respectively. In the second part of the study, 20 other subjects from each patient group (n=60) were tested once using Diaspect Tm only and were given a questionnaire. A questionnaire was given to 25 community pharmacists, selected by convenience sampling. The sensitivity was higher for STAT-Site® M Hgb (100%), the specificity was higher for Diaspect Tm (51%) and the accuracy was higher for Diaspect Tm (56%). On testing with Diaspect Tm only, there was an improvement in the performance characteristics; sensitivity of 100%, specificity of 75%, positive and negative predictive values 38% and 100% respectively and accuracy of 78%. The mean Diaspect values (g/dL) were 13.9 (healthy), 12.9 (diabetes) and 11.8 (CKD) and the mean lab values (g/dL) were 14.7 (p=0.01), 13.4 (p=0) and 12.9 (p=0.117) respectively. The service charge which the participants are willing to pay is comparable to the pharmacists’ service charge (p=0.142).

III

The higher accuracy, the balance between sensitivity and specificity, and the ease of use of Diaspect Tm render it a superior Hb POCT device, compared to STAT-Site® M Hgb. Results for Diaspect Tm were in accordance with the standard at Hb concentrations ranging from 10.4g/dL to 13.9 g/dL (CKD patients) whereas statistically significant differences were observed at higher Hb concentrations. POCT for Hb measurement may be offered from community pharmacies to support patient monitoring especially in patients who are known to be anaemic.