Population data experts are forcing a rethink of how we deal with ageing and disease

Every time you use the healthcare system, a new record is made. There are records for when you are admitted to hospital or an emergency department; records documenting your routine health screenings; and records for when you are born and when you die.

Each record marks a
personal event on the road map of your life.

After being
scrubbed of identifying information to ensure confidentiality and anonymity, these
records can be used by health researchers and policy-makers to better understand how patients move
through public and private hospitals across NSW.

By finding patterns
in the diseases we have and the ways we use our local health services, researchers
can tease apart how things like location, socio-economic status, and behavioural
risk factors can influence medical outcomes. They can also provide insights
into the quality of healthcare we receive.  

It’s this power of
data, and the way it can be used in an efficient, cost-effective manner to
solve health problems and identify emerging medical concerns, that drives Associate
Professor Sarah Thackway, Executive Director of the Centre for
Epidemiology and Evidence at the NSW Ministry of Health.

According to
Thackway, the state of NSW undertakes complex analytics to better understand
the health of the population in the state. It releases roughly 900 million
anonymised records per year to researchers who use them to make new discoveries
and develop deeper insights for public benefit.

Real-world evidence

NSW’s Centre for
Health Record Linkage (CHeReL) houses some 164 million records from 14.2
million people in NSW and the ACT, linking records from 25 related datasets.

Record linkage
centres like the CHeReL and the national Population Health Research Network equip
researchers with what’s known as ‘whole-of-population data’, which can reveal
insights that are almost impossible to access through routine studies or
clinical trials.

New medical
treatments are rigorously tested using randomised clinical trials, but in order
to produce high-quality evidence for specific conditions, people who have additional
health conditions are generally excluded from participating.

This of course
limits what researchers can learn about these treatments in a controlled
setting, says Foundation Director of the Centre for Big Data Research in Health
at UNSW, Professor
Louisa Jorm.

If the trial is
successful and the treatment is registered for use, “it goes out into the real
world, and is used in people who are not at all like the people who were in the
trial”, she explains.

Pregnant women, for
example, are usually excluded from trials on ethical grounds. Yet with the
increasing prevalence of chronic diseases such as type 2 diabetes and
hypertension, the reality is that many women with these conditions will require
treatment during their pregnancies.

The real-world
evidence gained from linking Pharmaceutical Benefit Scheme (PBS) data with the state’s
Perinatal Data
Collection – which monitors trends in pregnancy care, services, and
outcomes ­– has allowed researchers to identify the effects of different types
of medications on pregnant women.

So far, the
research has found little evidence of adverse outcomes.

“It’s one of those
things that we need really large and whole-of-population data to look at,
because many of the outcomes are quite rare,” says Jorm.

Ensuring equity for all

Analysis of
whole-of-population data allows NSW Health to ensure the delivery of its
population health programs to those who need it, in an effort to prevent
chronic diseases such as type 2 diabetes.

“Disadvantage is
the main cause of preventable health issues,” says Thackway.

“We can look at
particular geographical areas of need, where there are socio-economic disparities,
and make sure our programs are targeted to those communities. Our programs aim
for better health and wellbeing for all, and to achieve the full health
potential for our communities.”

An example of this
is the NSW Centre for
Population Health (CPH) using PBS prescribing data to monitor the
success of its hepatitis c strategy.

In March 2016, new
and more effective antiviral medications for hepatitis c became available under
the PBS. These new treatments are highly effective, with a cure rate of 95%,
says the CPH’s Executive Director, Dr Jo Mitchell.

High levels of
treatment and cure will mean that fewer people in the population are infected
with hepatitis c, leading to significant reductions in the transmission of the
virus to others.

The anonymous PBS
data is used by the CPH to track how many people are accessing hepatitis c
treatment in each local health district, so they can focus their efforts on
people who are living with the disease and link them to treatment services.

The strategy aims
to treat 90% of people with hepatitis c in NSW.

“We’ve treated about 26% of people statewide so far,” says Mitchell. “We use these data to help ensure that focus, and that we put everything in place to meet our goal of virtual elimination by 2028.”

From personalising treatment for infectious and chronic disease to informing the delivery of more effective preventative health policy, our ability to link and mine whole-of-population data will improve healthcare for everyone well into the future.

By Viki Cramer