\documentclass[table]{bmcart}


\usepackage{booktabs} % for e.g. \toprule
\usepackage{tabularx}
\usepackage{graphicx}


\renewcommand{\topfraction}{.85}
\renewcommand{\bottomfraction}{.7}
\renewcommand{\textfraction}{.15}
\renewcommand{\floatpagefraction}{.66}
\renewcommand{\dbltopfraction}{.66}
\renewcommand{\dblfloatpagefraction}{.66}

\newcommand{\chprefix}{A}
\renewcommand\thefigure{\chprefix.\arabic{figure}}

\begin{document}

\setcounter{figure}{1}
\begin{figure}[ht!]
    \centering
    \includegraphics[width = 0.8\textwidth]{plots/QQnormlog.pdf}
    \caption{QQ-plot of model residuals for log-transformed DV {\em Duration Stay}}
    \label{fig:QQplotlog}
\end{figure}

\end{document}