Jake Graft pointed out in a comment that I had forgotten to put the init script from the MythTV book online. My apologies.
#! /bin/sh
#
# mythbackend
#
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
BACKEND=/usr/local/bin/mythbackend
BACKEND_NAME=mythbackend
MYTHUSER="myth"
test -x $BACKEND || exit 0
set -e
case "$1" in
start)
echo -n "Starting MythTV: $BACKEND_NAME"
su ${MYTHUSER} -c "$BACKEND -v all -d -l ${MBE_LOGFILE}" &
echo "."
;;
stop)
echo -n "Stopping MythTV: $BACKEND_NAME"
killall $BACKEND
echo "."
;;
*)
echo "Usage: $0 {start|stop}" >&2
exit 1
;;
esac
exit 0