\documentclass[table]{bmcart}


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\usepackage{tabularx}

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\begin{document}

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\begin{table}[ht!]
\caption{Variable importances for the CV selected model concerning stroke and heart attack data for the DV \emph{Duration Stay}.}
    \centering
    \begin{tabularx}{\textwidth}{X r r r}
    \toprule
  \multicolumn{4}{l}{\textbf{Stroke data}} \\
    \midrule
     \emph{Internal transfer}          & 100\% (.27) & 100\% (.25) & 100\% (.24) \\ 
   \emph{Planned admission}          & 100\% (.56) & 100\% (.22) & \phantom{00}0\% (--) \\
   \emph{elix 23}            & \phantom{00}0\% (--)    & 100\% (.12) & 100\% (.12) \\
   \emph{elix 7}             & \phantom{00}0\% (--)     & 100\% (.11)&\phantom{0}80\%(.09)\\
    \emph{elix 24}      & \phantom{00}0\% (--) & \phantom{0}80\%(.10) &\phantom{0}90\%(.10)\\
     \emph{elix 6}          & \phantom{00}0\% (--) & \phantom{0}90\% (.10) & \phantom{0}50\% (.09) \\
     \emph{MDRG B04}        & \phantom{0}60\% (-.14) & \phantom{0}80\% (-.10) & \phantom{00}0\% (--) \\
   \emph{Part surgical}     & \phantom{0}50\% (.16)& \phantom{0}40\% (.14) & \phantom{0}20\% (.11)\\
    \emph{Emergency}       & \phantom{0}90\% (.17)  & \phantom{00}0\% (--)  & \phantom{00}0\% (--)\\
    \emph{MDC 1}           & \phantom{0}10\% (-.15)& \phantom{0}40\% (-.15) & \phantom{0}40\% (-.14)\\
    \emph{MDRG B70}        & \phantom{0}10\% (-.17) & \phantom{0}60\% (-.15) &\phantom{0}20\% (-.10)\\
   \emph{From home}       & \phantom{0}60\% (-.14) & \phantom{00}0\% (--) & \phantom{00}0\%(--) \\
  \emph{From hospital}    & \phantom{0}20\% (.13) & \phantom{00}0\% (--) & \phantom{00}0\% (--)\\
  \emph{elix30}            & \phantom{00}0\% (--)&  \phantom{0}10\% (.08)  &  \phantom{00}0\% (--) \\
  \midrule
   \multicolumn{4}{l}{\textbf{Heart attack data}} \\
  \midrule
   \emph{MDRG F24}       & 100\%  (-.45)     & 100\%  (-.51)     & 100\% (-.46) \\ 
   \emph{Transfer 24h}   & 100\%    (-.45) & 100\% (-.16)     & 100\% (-.10) \\
   \emph{elix 1}         & \phantom{0}60\% (.11) & 100\% (.13) & 100\% (.12) \\
   \emph{elix 23}        & \phantom{00}0\% (--)    & 100\%  (.10)     & \phantom{0}80\% (.09) \\
   \emph{Part surgical}  & \phantom{0}60\% (.53) & \phantom{0}10\% (.66) & \phantom{0}10\% (.45) \\
    \emph{Part medical}  & \phantom{0}40\% (-.47) & \phantom{0}90\% (-.56)   & \phantom{0}20\% (-.11) \\
   \emph{Emergency}      & \phantom{00}0\% (--) & 100\% (-.13) & \phantom{00}0\% (--) \\
    \emph{Planned admission}  & 100\%  (.24)     & \phantom{00}0\% (--) & \phantom{00}0\% (--) \\
   \emph{Pre-MDC}        &  \phantom{00}0\% (--)  & 100\%  (.11)     & \phantom{00}0\% (--) \\
   \emph{Doctor}         &  \phantom{00}0\% (--)  & \phantom{0}10\% (.09) & \phantom{00}0\% (--) \\
   \bottomrule
    \end{tabularx}
      \flushleft
  \begin{footnotesize} 
    \emph{Note.} Rates of being among the five most important variables (according to absolute values of regression coefficients) across the 20 sub-samples in percent; in brackets: mean estimated regression coefficient over all sub-samples.
    \end{footnotesize}
    \label{tab:selpred}
\end{table}

\end{document}