Minipage for two descriptions

I am attempting to use minipage to put two descriptions side by side. I have successfully used minipages for figures and tables, but for some reason this one won't work. Here is the code.

\begin{description}
\begin{minipage}{0.45\linewidth}
\item Risk Score Policy A
\begin{enumerate}
\item Maximum of four patients of rank 2
\item All remaining patients of rank 1
\end{enumerate}
\item Risk Score Policy A Alternate 1
\begin{enumerate}
\item Maximum of four patients of rank 2
\item All remaining patients of rank 1
\item Alternate patients of ranks 1 and 2
\end{enumerate}
\item Risk Score Policy A Alternate 2
\begin{enumerate}
\item Maximum of four patients of rank 2
\item All remaining patients of rank 1
\item All rank 2 patients first then all remaining rank 1
\end{enumerate}
\end{minipage}

\hspace{0.5cm}

\begin{minipage}{0.45\linewidth}
\item Risk Score Policy B
\begin{enumerate}
\item Maximum of two rank 3 patients
\item Maximum of two rank 2 patients
\item All remaining patients rank 1
\end{enumerate}
\item Risk Score Policy B Alternate 1
\begin{enumerate}
\item Maximum of two rank 3 patients
\item Maximum of two rank 2 patients
\item All remaining patients rank 1
\item Alternate rank 2+ patients with rank 1 patients
\end{enumerate}
\item Risk Score Policy B Alternate 2
\begin{enumerate}
\item Maximum of two rank 3 patients
\item Maximum of two rank 2 patients
\item All remaining patients rank 1
\item All rank 2+ patients first followed by all rank 1 patients
\end{enumerate}
\end{minipage}
\end{description}

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You want your code to match your english description, two minipages each containing a description so not

\begin{description}
\begin{minipage}{0.45\linewidth}


\begin{minipage}[t]{0.45\linewidth}
\begin{description}


Then as noted by Torbjørn in the comments you must have no blank line between the minipages so it should look like

\end{description}
\end{minipage}%
\hfill
\begin{minipage}[t]{0.45\linewidth}
\begin{description}


with no blank line and using a % and \hfill to separate the minipages rather than a fixed width (otherwise the total width will not add up correctly)

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That fixed it. Thank you. –  user24080 Jan 7 '13 at 15:57

You may also want to use \begin{minipage}[t]{0.45\linewidth} to align the top of the minipages, otherwise they will be centered vertically, which looks odd if the minipages aren't the same size. Alternatively you can also use [b] to align the end of the minipages.

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+1 yes good catch I'll add that to the code fragment in my answer if you don't mind:-) (welcome to tex.sx!) –  David Carlisle Jan 7 '13 at 16:02