## 3 Results  
The mean chronological age \(\pm\) SD of the participants was 8.75 \(\pm\) 2.66 years (male: 9.49 \(\pm\) 3.06; female: 8.21 \(\pm\) 2.18) (Table 1). According to the age distribution, the largest group included 498 participants (65.8%) aged \(\geq\)5 years but \(<\)10 years, which refers to most ages within the early and mid-puberty stages according to the major developmental stages of the skeletal system [pre-puberty (males \(\leq\)9 years; females \(\leq\)7 years); early and mid-puberty (9 years \(<\) males \(\leq\) 14 years; 7 years \(<\) females \(\leq\) 13 years); late puberty (14 years \(<\) males \(\leq\) 16 years; 13 years \(<\) females \(\leq\) 15 years); and post-puberty (males \(>\) 16 years; females \(>\) 15 years)) [13]. The mean bone ages \(\pm\) SDs assessed by the model were 9.15 \(\pm\) 3.21 for the left hand and 9.20 \(\pm\) 3.23 for the right hand (\(p<\) 0.001). The mean of the ADBH model was 0.23 \(\pm\) 0.19 years (95% CI: 0.22-0.25); 92.2% of participants showed an ADBH model result of \(<\)0.5 years. The results of the Bland-Altman analysis, which was used to assess the agreement between each hand's BAA, are shown in Figure 2. The mean difference between both hands' BAAs was 0.05 years (95% CI, 0.63-0.53); 4.6% (35/767) of the data were outside the limits of agreement. The Passing-Bablok regression analysis showed that the overall correlation of the BAA between both hands was excellent, having no significant deviation from linearity in this association (\(p=0.15\)) (Figure 3). According to the model, the bone age of the right hand was approximately 1 month more advanced than that of the left. The [PERSON]'s correlation coefficient was r = 0.995 (\(p<0.001\)) for the BAA between both hands. \begin{table}
\begin{tabular}{l c c c} \hline \hline
**Variables** & **Total (\(n=757\))** & **Male (\(n=321\))** & **Female (\(n=436\))** \\ \hline Age, years a  & 8.75 \(\pm\) 2.66 & 9.49 \(\pm\) 3.06 & 8.21 \(\pm\) 2.18 \\ \hline Age distribution, years & & & \\ \(<\)5 & 56/757 (7.4\%) & 23/321 (7.2\%) & 33/436 (7.6\%) \\ \(\geq\)5 and \(<\)10 & 495/757 (65.8\%) & 161/321 (50.2\%) & 337/436 (77.3\%) \\ \(\geq\)10 and \(<\) 15 & 190/757 (25.1\%) & 126/321 (39.3\%) & 64/436 (14.7\%) \\ \(\geq\)15 & 13/757 (1.7\%) & 11/321 (3.4\%) & 2/436 (0.5\%) \\ \hline \multicolumn{4}{l}{Automatic bone age assessment by the model} & 0.775 \\ Left hand a  & 9.15 \(\pm\) 3.21 & 9.85 \(\pm\) 3.72 & 8.63 \(\pm\) 2.67 \\ Right hand a  & 9.20 \(\pm\) 3.23 & 9.90 \(\pm\) 3.72 & 8.69 \(\pm\) 2.72 \\ ADBH model b  & 0.23 \(\pm\) 0.19 & 0.24 \(\pm\) 0.19 & 0.23 \(\pm\) 0.19 (0.21, 0.25) \\ \(<\)0.25 & 510/757 (67.4\%) & 215/321 (67.0\%) & 295/436 (67.7\%) \\ \(\geq\)0.25 and \(<\)0.5 & 188/757 (24.8\%) & 80/321 (24.9\%) & 108/436 (24.8\%) \\ \(\geq\)0.5 and \(<\)0.75 & 48/757 (6.3\%) & 20/321 (6.2\%) & 28/436 (6.4\%) \\ \(\geq\)0.75 and \(<\)1 & 11/757 (1.5\%) & 6/321 (1.9\%) & 5/436 (1.1\%) \\ \hline \hline \end{tabular} Unless otherwise indicated, the data are presented as the number of patients, with percentages in parentheses. ADBH model, the absolute difference between each hand’s bone age assessment. a The data are presented as means \(\pm\) standard deviation. b The data are shown as the means \(\pm\) standard deviation, with the 95% confidence interval in parentheses.  
\end{table} 
Table 1: The baseline characteristics of the subjects. model result of >0.5 years. There was a statistical difference according to developmental stage; the majority of patients in the pre-puberty and early/mid-puberty groups showed an ADBH model result of <0.5 years. With an ICC (95% CI) of 0.997 (95% CI, 0.996-0.998), the agreement between the two reviewers was sufficiently high to justify using the average BAA value as a reference standard. The reference standard showed no statistical differences between the BAAs of each hand (Table 3).