Among those who present to the emergency department for self-harm, many will
repeat. Self-harm repetition is an outcome of interest in both observational
and intervention studies. However, few such studies analyse the number of
repeat self-harm presentations. Here, hurdle models are introduced as a
potentially useful statistical method for these analyses. Emergency
department data from the Province of Ontario, Canada, are used to illustrate
an example of implementing hurdle models and interpreting their results.