A novel software for method comparison: MCS (method comparison software)—assessing agreement between estimated fetal weights calculated by Hadlock I–V formulas and birth weight

Abstract

Abstract Introduction The evaluation of the performance of new methods, expected to provide cheaper and faster results than existing (reference) methods in the health field, is based on comparing the results obtained with this new method to those obtained with the existing method. The primary aim of this study is to examine the correlational and absolute agreement between measurement methods in clinical studies using Bland–Altman analysis and methodological (Ordinary Least Squares, Weighted Ordinary Least Squares, Deming, Weighted Deming, Passing–Bablok, Theil-Sen, and Passing–Bablok for Large Data Sets.) methods, and the secondary aim is to compare the accuracy and precision of Hadlock (I–V) formulas used for fetal weight estimation. Materials and methods The study was conducted on singleton pregnancies examined in the Prenatal Diagnosis and Treatment Unit of the Department of Obstetrics and Gynecology at Inonu University Faculty of Medicine and who gave birth in the Obstetrics Unit between 01.01.2020 and 01.09.2023, whose gestational ages were confirmed by first-trimester ultrasonography. Estimated fetal weights were calculated using Hadlock (I–V) formulas, and the agreement of these weights with birth weight was evaluated with Bland–Altman method. Results The comparison of estimated fetal weights calculated using Hadlock formulas with birth weight was analyzed using Bland–Altman analysis, ICC, and CCC values along with regression analyses. According to the mean difference values obtained by Bland–Altman analysis, the estimated fetal birth weights obtained by the Hadlock IV formula were most consistent with the actual birth weights. Conclusions The estimated fetal weights obtained using the Hadlock IV formula resulted in the closest measurements to the birth weight. This study showcases the efficacy of a new web-based software, Method Comparison Software (MCS), which can be utilized for evaluating the agreement between different methods in clinical measurements.