Published studies conducted to validate the NBM 200 sensor
| Ref | First author, year of publication | Study settings | Country, population and sample size | Method of comparison and gold standard used | NBM 200 performance |
|---|---|---|---|---|---|
| 1 | Gayat, 2012 | Emergency department, Foch university hospital, Suresnes, France | France Patients reporting to the emergency department n=569 and for NBM 200 n=297 (men 157 and women 140) Males 52.9% Females 47.1% Data analysed for 270 patients | Descriptive data, student t test, Bland-Altman analysis, intraclass correlation, multivariate linear regression to identify variables associated with bias ADVIA 2120 (Siemens Medical Solutions Diagnostics, Zurich, Switzerland) | Bias: 0.21 g/dL (95% CI 0.02 to 0.39) Bland-Altman analysis Upper limit of agreement (ULA): 3.42 g/dL (95% CI 3.10 to 3.74) Lower limit of agreement (LLA): −3.01 g/dL (95% CI −3.32 to −2.69) Intraclass correlation coefficient: 0.69 (95% CI 0.62 to 0.75) Coefficient of variation (CV): 5.9% True values of haemoglobin (Hb) and perfusion index were independently associated with NBM 200. Despite the limited bias, a wide level of agreement was found; thus, clinical usefulness is debatable |
| 5 | Singh, 2015 | Blood donation centre in tertiary care institute, India | India Blood donors n=534, and 485 included in the analysis for NBM 200 (men 455, women 30) n=485 Males 94% Females 6% | Bland-Altman analysis, intraclass correlation coefficient, specificity, sensitivity, negative predictive value (NPV) and positive predictive value (PPV). Sysmex KX-21 (Sysmex Corporation, Kobe, Japan) | Mean Hb by NBM 200:14.8 g/dL Mean Hb by the gold standard: 14.1 g/dL SD for NBM 200 >2.0 g/dL, on comparing with the gold standard. Bland-Altman agreement ULA: 2.09 g/dL (95% CI 1.88 to 2.30) LLA : −3.39 g/dL (95% CI −3.61 to −3.19) Bias: −0.66 g/dL (95% CI −0.78 to −0.53) Sensitivity 71.7%, specificity 79.5%, NPV 95.8%, PPV 30.2% Intraclass correlation: 0.43 (95% CI 0.27 to 0.55) NBM 200 did not detect 45.5% of ineligible donors. NBM 200 has benefit of pain elimination but carries a substantial possibility of ineligible donor selection |
| 6 | Malukani, 2014 | Blood donation centre in tertiary care hospital, Ahmedabad, Gujarat, India | India Blood donors n=200 (men 192, women 8) Males 96% Females 4% | Specificity, sensitivity, NPV and PPV. Sysmex KX 21 (Sysmex America Inc., Lincolnshire) | Mean Hb by NBM 200: 13.5 g/dL (SD 1.4) Sensitivity 96.36%, Specificity 91.43%, NPV 84.21%, PPV 98.15% Likelihood ratio 8.22 The results by NBM 200 showed wide variation when compared with the gold standard, but the mean of difference was non-significant |
| 8 | Hadar, 2012 | Women's hospital, Rabin Medical centre, Petah Tikva, Israel | Israel Pregnant women n=63 Average age 31.3 years (range 21–25) Average gestational age 35.9 weeks (range 13–41 weeks) | Bland-Altman analysis LH750 automated haematology analyser (Beckman Coulter Inc., Brea, California, USA) | Hb range obtained by NBM 200: 7.7 g/dL–14.0 g/dL SD 0.86 g/dL Bland-Altman agreement: −1.59 g/dL to 1.79 g/dL Correlation coefficient: 0.82 Mean absolute error: 0.71 g/dL Hb range obtained by gold standard: 6.9 g/dL–13.9 g/dL Study demonstrates good correlation with the gold standard and NBM 200 measures Hb accurately |
| 12 | Ardin, 2015 | Blood donation centre of the Institute for Transfusion Medicine of the University Hospital of Cologne, Germany | Germany Blood donors Donors age mean 36 years (SD 14) n=351, and for NBM 200 n=120 (through phase 1 of the study, 78 men and 42 women) Men 65% Women 35% | Bland-Altman analysis Sysmex KX-21n, (Sysmex Europe GmbH, Norderstedt, Germany) | SD for NBM 200 1.14 g/dL, on comparing with the gold standard Bland-Altman agreement: −2.35 g/dL to 2.11 g/dL Bias: −0.12 g/dL False rejection of seven donors, however, no correspondent unacceptable classification occurred NBM 200 obtained lower Hb levels in women |
| 13 | Kim, 2013 | Two blood donation sites affiliated to the Hanmaum Blood centre, Gwacheon, Korea | Korea Blood donors n=506 (men 291, women 215) Males 57.5% Females 42.4% | Bland-Altman analysis, Specificity and Sensitivity. LH500 automated haematology analyser (Beckman Coulter Inc., Brea, California, USA) | Mean Hb by NBM 200: 14.1 g/dL Intraclass correlation between NBM 200 and LH500: 0.86 NBM 200 Hb <12.0 g/dL in 37 participants (mean 12.4, SD 1.2) Hb=12.0 to 12.4 g/dL in 18 participants (mean 12.8, SD 1.1) Hb ≥12.5 g/dL in 451 participants (mean 14.4, SD 1.2) Bland-Altman plot showed 2 SD difference in Hb estimations between LH500 and NBM 200, Hb >2.0 g/dL. Whole blood Sensitivity 38.6% (95% CI 28.1% to 50.3%) Specificity 93.6% (95% CI 90.9% to 95.5%) Apheresis Sensitivity 37.8% (95% CI 24.1% to 53.9%) Specificity 94.0% (95% CI 91.5% to 95.8%) Out of 70 ineligible donors (Hb <12.5 g/dL) according to the gold standard (LH500), 43 donors (61.45%) were considered eligible by NBM 200 |
| 14 | Pagliaro, 2014 | Immunohematology and Transfusion Medicine Collection site of S. Orsola Malpighi Hospital, Bologna, Italy | Italy Blood donors Data from year 2012 NBM 200 (n) Men=2945 Women=1021 Data from year 2013 (n) NBM 200 Men=2895 Women=1100 | Specificity, sensitivity, NPV and PPV Donors were classified into fit and unfit sections Haematocytometry tests as a reference in the year 2012 Beckman Coulter's AcT-5 diff AL (Beckman Coulter Inc., Brea, California, USA) as a gold standard in the year 2013 | 2012: NBM 200 and Haematocytometry test Women (n=1021) Sensitivity 32.34%, specificity 95.12%, NPV 85.15% and PPV 61.90% Men (n=2945) Specificity 98.89%, sensitivity 14.47% NPV 95.30% and PPV 42.59% 2013: NBM 200+targeted venous sample (gold standard, Beckman Coulter) Women (n=1100) Sensitivity 45.76%, specificity 99.24%, NPV 90.51% and PPV 92.05% Men (n=2895) Sensitivity 36.03%, specificity 99.93%, NPV 96.94% and PPV 96.08% Compared to non-invasive techniques, a venous sample improves donor selection |
| 15 | Belardinelli, 2013 | Immunohematology and Transfusion Medicine Collection site of S. Orsola Malpighi Hospital, Bologna, Italy | Italy Blood donors n=445 (men 296, women 149) Males 66.5% Females 33.4% | Bland-Altman analysis, Specificity and Sensitivity. Beckman Coulter's AcT-5 diff AL (Beckman Coulter Inc., Brea, California, USA) | Bland-Altman agreement: −1.64 g/dL to 2.21 g/dL Bias: 0.29 g/dL SD: 0.98 g/dL Percentage of donors screened correctly by NBM 200: 88% Sensitivity 98%, specificity 97% Non-invasive technique does not replicate results of the venous sample, and compared to finger-prick (HamoCue), the NBM 200 had low sensitivity and specificity |