  Magnetars are strongly magnetized pulsars and they occasionally show violent
radiative outbursts. They also often exhibit glitches which are sudden changes
in the spin frequency. It was found that some glitches were associated with
outbursts but their connection remains unclear. We present a systematic study
to identify possible correlations between them. We find that the glitch size of
magnetars likely shows a bimodal distribution, different from the distribution
of the Vela-like recurrent glitches but consistent with the high end of that of
normal pulsars. A glitch is likely a necessary condition for an outburst but
not a sufficient condition because only 30\% of glitches were associated with
outbursts. In the outburst cases, the glitches tend to induce larger frequency
changes compared to those unassociated ones. We argue that a larger glitch is
more likely to trigger the outburst mechanism, either by reconfiguration of the
magnetosphere or deformation of the crust. A more frequent and deeper
monitoring of magnetars is necessary for further investigation of their
connection.
