Evaluation of the use of non-invasive hemoglobin measurement in early childhood

Background Iron deficiency anemia in children affects psychomotor development. We compared the accuracy and trend of a non-invasive transcutaneous spectrophotometric estimation of arterial hemoglobin (Hb) concentration (SpHb) by rainbow pulse CO-oximetry technology to the invasive blood Hb concentration measured by an automated clinical analyzer (Hb-Lab). Methods We measured the SpHb and Hb-Lab in 109 patients aged 1–5 years. Regression analysis was used to evaluate differences between the two methods. The bias, accuracy, precision, and limits of agreement of SpHb compared with Hb-Lab were calculated using the Bland–Altman method. Results Of the 109 enrolled subjects, 102 pairs of the SpHb and Hb-Lab datasets were collected. The average value of measured Hb was 12.9 ± 1.03 (standard deviation [SD]) g/dL for Hb-Lab. A significant correlation was observed between SpHb and Hb-Lab measurements (SpHb = 7.002 + 0.4722 Hb-Lab, correlation coefficient r = 0.548, 95% confidence interval = 0.329–0.615). Bland–Altman analysis showed good visual agreement, with a mean bias between SpHb and Hb-Lab of 0.188 ± 0.919 g/dL (mean ± SD). Conclusions We concluded that non-invasive Hb measurement is useful for Hb estimation in children and provides new insights as a screening tool for anemia. Impact Our results indicated a good correlation between non-invasive transcutaneous spectrophotometric estimation of arterial hemoglobin (Hb) concentration using a finger probe sensor by rainbow pulse CO-oximetry technology and invasive blood Hb concentration. Although previous studies have indicated that in patients with a worse condition, the bias between the two methods was large, this study, which was conducted on children with stable disease, showed a relatively small bias. Further studies using this non-invasive device might help to understand the current status of anemia in Japan and promote iron intake and nutritional management in children.