Data from: Duration and economic value of a walking-in-nature therapy program: Implications for conservation

Nature exposure, such as visiting protected areas, provides mental health
benefits that reduce healthcare costs and improve productivity, with
global values in the trillions. Countries are bringing nature-based
programs into mainstream mental healthcare via nature therapies. This
study quantifies the scale, duration, and economic value of mental health
benefits from a long-established nature therapy program and implications
for conservation. Using a Before-After-Control-Impact design, we evaluated
a 12-week nature walking program with social mechanisms for therapeutic
adherence. Mental health was assessed using the Personal Wellbeing Index,
a measure of subjective well-being, with participants and controls from
the same subpopulation. Measurements occurred at program start, end, and
12 weeks post-intervention. Economic benefits were calculated using the
financial value of quality-adjusted life-years. The nature-based therapy
program improved the mental well-being of participants during the program
and for at least three months afterwards. While controls showed well-being
improvements when they reported having physically exercised (despite not
being instructed to), program participants exhibited an additional
Personal Wellbeing Index increase of 5.1%. Training in nature was a
critical component, leading to the highest increase in mental health
benefits and doubling of their duration (up to 12 months). The mean total
economic benefit per participant who followed the program design in full
was c.AU$4,000. Total economic contribution via mental health, adjusted
for socioeconomic and demographic factors, participation patterns,
post-program fade-out, and the national number of participants each year,
is therefore c.AU$20 million per annum. 5. Mental health benefits of
nature visits fade once people stop visiting parks. To maximise their
contribution to political and economic support for protected areas,
therefore, the focus for future research and practice should be on social
mechanisms to promote lifelong park visit habits.