## 3 Results
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Variable \({}^{\ast}\)**} & \multicolumn{3}{c}{**Prefrail vs. Robust**} & \multicolumn{3}{c}{**Frail vs. Robust**} \\  & **OR** & **95\% CI** & \(p\) **Value** & **OR** & **95\% CI** & \(p\) **Value** \\ \hline TUG time, s & 2.36 & 1.68–3.31 & **<0.001** & 2.67 & 1.89–3.78 & **<0.001** \\ Dynamic gait index, score & 0.80 & 0.70–0.92 & **0.001** & 0.71 & 0.60–0.83 & **<0.001** \\ Gait speed, cm/s & 0.93 & 0.90–0.95 & **<0.001** & 0.92 & 0.89–0.95 & **<0.001** \\ Stride time, ms & 1.006 & 1.003–1.009 & **<0.001** & 1.006 & 1.003–1.009 & **<0.001** \\ Swing phase time, ms & 1.007 & 1.001–1.013 & **0.028** & 1.008 & 1.001–1.015 & **0.024** \\ Stance phase time, ms & 1.009 & 1.005–1.013 & **<0.001** & 1.008 & 1.004–1.012 & **<0.001** \\ Swing phase,\% & 0.80 & 0.71–0.91 & **0.001** & 0.69 & 0.60–0.90 & **<0.001** \\ Stance phase,\% & 1.24 & 1.10–1.41 & **0.001** & 1.44 & 1.25–1.67 & **<0.001** \\ Double support time, ms & 1.02 & 1.01–1.03 & **<0.001** & 1.01 & 1.01–1.02 & **0.002** \\ Cadence, steps per min & 0.87 & 0.83–0.92 & **<0.001** & 0.83 & 0.78–0.89 & **<0.001** \\ \hline \hline \end{tabular} \({}^{\ast}\) Multinomial logistic regression with the robust group as reference. Statistically significant values highlighted in bold. OR = odds ratio, CI = confidence interval. TUG = timed up and go test.  
\end{table} 
Table 4: The parameters for discriminating three frailty levels (robust, prefrail, and frail). \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Variables \({}^{\ast}\)**} & \multicolumn{3}{c}{**Frail vs. Prefrail or Robust**} & \multicolumn{3}{c}{**Prefrail or Frrail vs. Robust**} \\  & **AUC** & **Cut-Off Value \({}^{a}\)** & **Sens. (\%)** & **Spec. (\%)** & **AUC** & **Cut-Off Value \({}^{a}\)** & **Sens. (\%)** & **Spec. (\%)** \\ \hline TUG test time, s & 0.790 & 11.60 & 86.1 & 65.6 & 0.929 & 9.27 & 89.2 & 86.7 \\ DGI, score & 0.675 & 15.00 & 54.1 & 75.0 & 0.735 & 19.0 & 73.8 & 56.7 \\ Ch. gait speed, m/s & 0.801 & 0.59 & 83.8 & 68.8 & 0.969 & 0.74 & 91.3 & 90.0 \\ S. gait speed, m/s & 0.810 & 0.60 & 78.4 & 75.0 & 0.958 & 0.82 & 94.2 & 86.7 \\ Stride time, s & 0.740 & 1.27 & 91.9 & 51.0 & 0.915 & 1.19 & 90.3 & 86.7 \\ Stance time, s & 0.773 & 0.80 & 83.8 & 62.5 & 0.923 & 0.68 & 96.1 & 73.3 \\ Swing time, s & 0.569 & 0.48 & 59.5 & 57.3 & 0.759 & 0.48 & 58.3 & 86.7 \\ Stance phase,\% & 0.749 & 63.15 & 75.7 & 68.8 & 0.788 & 63.27 & 53.4 & 96.7 \\ Swing phase,\% & 0.749 & 36.85 & 75.7 & 68.8 & 0.790 & 36.73 & 53.4 & 96.7 \\ D5 time, s & 0.778 & 0.16 & 70.3 & 76.0 & 0.858 & 0.14 & 62.1 & 96.7 \\ Cad., step/min & 0.724 & 99.54 & 94.6 & 44.8 & 0.930 & 101.22 & 84.4 & 90.0 \\ \hline \hline \end{tabular} \({}^{\ast}\) AUC = area under curve. TUG = timed up and go test. DGI = Dynamic Gait Score. Ch. gait speed measured by a chronometer. S. gait speed derived from sensor data. D\(\overline{\text{S}}\) = Double Support. Cad = Cadence. Sens = Sensitivity. Spec = Specify. \({}^{a}\) Cut-off value based on the Youden Index  
\end{table} 
Table 5: The most sensitive parameters for discriminating frail from prefrail or robust and prefrail or frail from robust. sensitivity (53.4% and 62.1%). Among the physical performance tests, TUG test time (AUC = 0.929) emerged as a sensitive parameter to discriminate between prefrail or frail and robust. The predictive validity of the dynamic gait index (AUC = 0.735) was inferior when compared to the other variables.