Increasing impact of mental health presentations on New South Wales public hospital emergency departments 1999-2006

Objective: The percentage of mental health (MH) presentations to New South Wales (NSW) EDs in recent years has not been described at the statewide level. Evidence from other states suggests this burden might be increasing. The present study aims to evaluate recent trends in MH presentations to NSW EDs, including geographic variations and the spectrum of MH disorders encountered. Methods: Data were sourced from the NSW Emergency Department Data Collection, which collates information from routine reporting undertaken in all NSW EDs. The database employs ICD-9 diagnostic descriptors. The present study retrospectively analyses presentations from 1999 to 2006 for patients who received an MH primary discharge diagnosis, as defined by ICD-9. In addition, rates of presentation for poisoning are considered. The percentage of MH presentations to the three largest hospital categories principal referral, major metropolitan and rural base (i.e. major non-metropolitan) - is examined. Results: During 1999 and 2006, there were 9 013 357 ED presentations at the study sites. Of these, 3.22% received an MH primary discharge diagnosis. An additional 0.93% received a diagnosis of poisoning. In 2006, there were 15 262 more MH presentations than in 1999, a 49.78% increase. Over this period, total annual ED presentations increased by 201 763 (19.30%). General population growth was 6.31%. Across the state, 32.0% of MH presentations were for psychotic conditions and 68.0% for neurotic illnesses. Conclusion: Mental health presentations to NSW EDs are increasing. There is a need to review emergency services to accommodate these changes. The reasons for this growth remain unclear and require formal prospective evaluation.