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A prospective cohort study of trends in self-poisoning, Newcastle, Australia, 1987–2012: plus ça change, plus c’est la même chose

Nicholas A Buckley, Ian M Whyte, Andrew H Dawson and Geoffrey K Isbister
Med J Aust 2015; 202 (8): 438-442. || doi: 10.5694/mja14.01116

Summary

Objective: To examine inhospital mortality and morbidity associated with self-poisoning with different drug classes over an extended period.

Design, setting and participants: A prospective cohort study over 26 years (1987–2012) with limited follow-up of patients presenting consecutively to a primary and tertiary referral toxicology centre covering Newcastle, Lake Macquarie and Port Stephens, Australia.

Main outcome measures: Hospital length of stay, types of drugs ingested, intensive care unit (ICU) admission, requirement for ventilation, inhospital deaths and rates of antidepressant drug use in Australia.

Results: Over the study period, there were 17 266 admissions of patients poisoned by 34 342 substances (16 723 drugs available only on prescription). The median length of stay was 16 hours, 12.2% of patients (2101/17 266) were admitted to an ICU, 7.4% (1281/17 266) were ventilated and 78 (0.45%) died in hospital. Patient demographics, social and psychiatric factors remained stable over the 26-year period, but case fatality decreased (from 0.77% [15/1955] to 0.17% [7/4060]) as did ICU admissions (19.2% [376/1955] to 6.9% [280/4060]), ventilation (13.7% [268/1955] to 4.8% [193/4060]) and LOS. The most frequently ingested substances were alcohol, benzodiazepines, paracetamol, antidepressants and antipsychotics. There was a substantial fall in some highly toxic drugs (tricyclic antidepressants, barbiturates, conventional antipsychotics and theophylline), but increases in less toxic selective serotonin reuptake inhibitors, serotonin–noradrenaline reuptake inhibitors and paracetamol. A greater than sixfold increase in community antidepressant use was accompanied by only minor changes in overall and antidepressant self-poisoning rates.

Conclusion: Over two decades, there were decreases in poisonings by many highly toxic drugs which were associated with substantial reductions in morbidity and inhospital deaths. Despite massive increases in the number of antidepressant prescriptions, neither rates of self-harm nor the proportion of antidepressant poisonings increased markedly.

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  • Nicholas A Buckley1
  • Ian M Whyte2,3
  • Andrew H Dawson4
  • Geoffrey K Isbister2,3

  • 1 University of Sydney, Sydney, NSW.
  • 2 Calvary Mater Newcastle, Newcastle, NSW.
  • 3 University of Newcastle, Newcastle, NSW.
  • 4 Royal Prince Alfred Hospital, Sydney, NSW.

Correspondence: geoff.isbister@gmail.com

Acknowledgements: 

Geoffrey Isbister is supported by an NHMRC Fellowship (1061041). Andrew Dawson is supported by an NHRMC Practitioner Fellowship (1059542). Ongoing toxicovigilance studies are supported by an NHMRC Program Grant (1055176). A great many people have contributed to the HATS database — including past registrars, advanced trainees, fellows, nursing staff, research assistants and computer programmers — and this work would not have been possible without their input.

Competing interests:

No relevant disclosures.

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access_time 12:10, 2 May 2015
Ken Gillman

The tremendous value of the HATS team members endeavour is highlighted in my area of expertise, serotonin toxicity, where one of the crucial elements is good systematically collected data on human toxicity of drugs and drug combinations. The HATS data has been by far the most valuable source of information for my research on ST without which most of my reviews would be of hugely diminished value.
We all owe the HATS team members a considerable debt of gratitude for what certainly required a great deal of hard work sustained over many years.
I would like to publically thank all the members of the HATS team over the years who surely are justifiably exceedingly proud of their considerable collective achievements.
One can only hope their example will galvanize others around the world to get on board and emulate their methods and thereby remedy (inter alia) the woeful paucity of quality post-marketing toxicity data.


Competing Interests: No relevant disclosures

Dr Ken Gillman
PsychoTropical Research

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