Young women, poor, dominate self-poisoning cases

Multimedia Journalist·NZ Herald·

30 Jul, 2017 01:20 AM5 mins to read

Kiwi researchers who investigated thousands of cases of intentional self-poisonings say more needs to be known about the substances being used because delaying access could help prevent people from harming themselves Photo / File

Kiwi researchers who investigated thousands of cases of intentional self-poisonings have shown how young women and people from deprived areas are most likely to end up in hospital emergency departments.

But of the average 2500 cases EDs saw each year, it was overwhelmingly men who were dying.

University of Otago researchers behind the new study say we need to know more about these cases, which include patients overdosing on drugs, or consuming excess alcohol or indigestible substances.

An analysis of more than 1880 poisoning deaths between 2000 and 2012 found a clear majority - 93 per cent - had been intentionally self-inflicted, and around two-thirds of those who died were men, and often young.

Around half of the 155 Maori patients and two thirds of 25 Pasifika patients who died were younger than 35.

While men were represented more strongly in death rates, women accounted for more than two thirds of all of the patients treated by ED doctors over a period stretching from 2000 to 2014.

About a third of the total 43,777 cases also involved patients younger than 25 - including 1737 cases with patients aged only between 10 and 14.

"The relatively high rates of admissions in young women aged 15 to 24 compared to other age groups and males, while expected from previous research, surprised us a bit," said lead researcher Eeva-Katri Kumpula, a PhD candidate at Otago's School of Pharmacy.

For three-quarters of the patients, their visit to the ED was the only one over the 15-year study period, although a small number were treated more than once in a single day.

The study further showed a clear link to deprivation, with rates of hospital presentations in the two most deprived quartiles double those in the least - a finding in line with general self-harm and suicide statistics.

The results also weren't surprising to Waikato Hospital ED clinical director Dr John Bonning, who said intentional self-poisonings were common cases faced by his colleagues.

"To pluck a figure out of the air, we'd see at least a dozen a day," said Bonning, who serves as chairman of the NZ Faculty of the Australasian College of Emergency Medicine.

"We care for them, give them good medical care and then get the mental health team to look after that side of things."

As the study didn't account for those patients who stayed in EDs less than 24 hours, went to GP clinics instead, or didn't seek medical help at all, the figures covered just a portion of all cases, Kumpula said.

"We were hoping to gain an understanding of who is at risk of intentional self-poisoning in New Zealand, and what we could learn about the substances - for example prescribed medications or alcohol - that they used in these events," she said.

Waikato Hospital ED clinical director Dr John Bonning said his department received around a dozen self-poisoning cases each day. Photo / File

As intentional overdoses were often impulsive acts, and the choice of substance taken seemed to depend on what was readily available, reducing access to such means was one of the most effective ways of preventing suicides, she said.

"Any delay in [gaining access] may lead to the person changing their mind, offering a window of opportunity for preventing at least some intentional overdoses."

Her study, just published in the Australian and New Zealand Journal of Public Health, also looked at whether national data collected by the Ministry of Health included enough detail about the substances to be useful for prevention efforts - and found it didn't.

"We used nine of the most commonly overdosed medicines at Wellington ED as indicators, and for all but one they could not be identified separately to see how frequently they occurred."

"This was due to the international system of describing diagnoses - it has not kept up to date with new drugs being available on the market, and some drugs just cannot be identified individually."

The study therefore recommended all EDs collect more detailed poisoning data, as was done automatically through computer records at Wellington ED and the UK's Queens Medical Centre.

"In this way we could understand local trends in poisoning better, and plan ways to prevent some of these overdoses."

By the numbers

• Intentional self-poisoning is involved in 65 per cent of all poison-related hospital presentations, with the rest either unintentional (29 per cent) or undetermined (6 per cent).
• Of 1881 self-poisoning deaths between 2000 and 2012, 93 per cent of these were deliberate.
• Sixty-seven per cent of those who died were men, 8 per cent were Maori, 1 per cent were Pasifika, 2 per cent were Asian and 88 per cent were categorised as "other", including NZ Europeans.
• Fifty per cent of the 155 Maori patients who died, and two thirds of 25 Pasifika patients, were younger than 35.
• Sixty-eight per cent of all self-poisoning presentations between 2000 to 2014 were women, 33 per cent were younger than 25, and rates of hospital presentations in the two most deprived quartiles were double those in the least.