People from Sydney’s affluent North Shore live more than eight years longer than residents of the Northern Territory and have markedly lower rates of potentially preventable deaths according to new data published by the Australian Institute for Health and Welfare also showing a steep social gradient in health risk factors.

The latest Healthy Communities report from the AIHW, Life Expectancy and Potentially Avoidable Deaths in 2013-2015, reveals stark disparities by postcode, with an 8.5-year gap between the Primary Health Network with the best longevity (Northern Sydney: 85.5 years) and the worst (Northern Territory: 77.0 years).

A similar profile was seen with potentially avoidable deaths, with the NT PHN coming in at 226 per 100,000 people (an increase from 219/100,000 two years earlier) compared with 62 per 100,000 for Northern Sydney. The AIHW defines these deaths, which represented 17% of all fatalities in 2013-15 (80,000 in total), as occurring before the age of 75 from causes that might have been treatable or preventable.

“Life expectancy has risen across most local communities, but substantial variation remains across Primary Health Network areas,” said AIHW spokesperson Claire Sparke.

Queenslanders enjoyed the largest gains to life expectancy over the period, with 4 PHNs (Brisbane North & South, Darling Downs and West Moreton, and Western Queensland) putting on 0.6 years. Victoria’s Gippsland PHN saw the largest decrease in life expectancy (0.5 years).

Overall, females continue to live an average of 4 years longer than their counterparts.

Breaking the data down by statistical area rather than PHN, the rate of potentially avoidable deaths was highest in the NT’s Daly-Tiwi-West Arnhem region (443/100,000) and lowest in Sydney’s Epping-West Pennant Hills. Regional PHNs were overrepresented compared to metropolitan PHNs (129 v 96/100,000).

Health risk factors

A regional vs metropolitan gradient was also evident in health risk factors, according to a separate update released by the AIHW showing risky lifetime drinking (20.4% vs 15.9%), sedentary lifestyle (62.4% vs 53.3%) and hypertension (39.3% vs 30.9%) were higher outside major centres.

Mental health admissions on the rise

A third update also published last week by the AIHW shows a steady increase in the national overnight admission rate for mental health, now at 102 per 10,000 people from 91 per 100,000 in 2013-14. Again, this is higher in regional as opposed to urban locations (106 vs 96/10,000), led by Country SA (135/10,000) with the ACT lowest (73/10,000), though the ACT also saw the highest increase in the past year (16%). Overall, one-third of PHNs saw overnight admissions for mental health increase by more than 10% over the past 12 months.

The AIHW cautioned that differences in hospitalisation rates could reflect not only the proportion of people with mental health conditions, but also their severity, and differences in access to community-based care.

By statistical area, Adelaide City had the highest overnight mental health hospitalisation rate (224/10,000), with Litchfield NT coming in lowest at 43/10,000).

The two most common disorders requiring admission were drug and alcohol use and schizophrenia and delusional disorders (representing 37% of all mental health hospitalisations and 42% of all mental health bed days.

Self-harm hospitalisations were more than three times higher in the Northern Territory (29/10,000) than Eastern Melbourne (9/10,000) — the PHNs with the highest and lowest rates respectively.