2.2 Model verification
Four published clinical articles were used for model validation (Eron et
al., 2004; Hsu et al., 1997; Mzayek et al., 2007; Na-Bangchang,
Limpaibul, Thanavibul, Tan-Ariya, & Karbwang, 1994). The absolute
average-folding errors (AAFEs) (the comparison between the predicted
results against clinical published data) were calculated to determine
model accuracy. AAFEs value below 2 is considered as acceptable
following recent publication (Saeheng, Na-Bangchang, & Karbwang, 2018).
AAFEs can be calculated using the following equation:
\begin{equation}
\text{AAFEs}=10^{\frac{\sum_{i=1}^{n}\left|\log\frac{\text{prediction}}{\text{observation}}\right|}{n}}\nonumber \\
\end{equation}Where n is the number of samples; the prediction and observation are
simulated results, and observed clinical data, respectively.