Transcript Public health perspective of trails and greenways

A public health perspective on
trails and greenways
Towards evidence-based
practice
Dafna Merom
NSW Centre for Physical Activity
and Health
Epidemiological questions
Physical activity
(PA)
Trail / Parks
Mental Health
Well being
Social benefits
Health benefits
Chronic disease
prevention and control
The topics of this talk

Health benefits of physical activity

Changes to public health recommendations and to
health promotion strategy

Environmental influences on physical activity
behaviour

Developing conceptual model guiding the research

Empirical evidence to support the effectiveness of
trail/parks

Recommendations for research and practice
Health benefits of physical activity
Total
mortality
Bone mass,
osteoporosis
PA
CVD
CHD
Prevent falls
High BP
Depression
Anxiety,
stress
Obesity
Colon
cancer
Enhance
mood, well
being
Other cancers?
Diabetes
Blood lipids
Health benefits is proportional to amount
Public health recommendations

Regular moderate-intensity physical activity

30 minutes on most, preferably all days of
the week.

This amount can be accumulated throughout
the day in several short 10-minutes bouts.

This is the minimum required, increase
amount result in increase benefits
Public health recommendations linked
to obesity epidemic

Consider all opportunity to be active: ‘walk
instead of using a car whenever you can’.

Incorporate physical activity into your daily
life; in transport, in occupational and
domestic settings.

Walking is considered as the most suitable
type of activity for widespread promotion.
Percentage of people achieving 150mins/wk
of at least moderate physical activity
1997
1999
2000
Men
63.4
59.6*
57.6**
Women
61.1
53.8*
56.0
All Sample
62.2
56.6*
56.8
* P<0.01
Source: Bauman et al. Active Australia Surveys, short-term trends
Percentage of people reporting no physical
activity (i.e. completely sedentary)
1997
20
15
1999
2000
17.5
13.4
14.6 15.3
13.7
14.7
14.6
13.1
13.1
10
5
0
All
Men
Women
Source: Bauman et al. Active Australia Surveys, short-term trends
Long-term trend in past week walking for
exercise
any walking
regular walking
60
52.5
48.8
50
44.6
40
30
20
14.6
14.4
14.7
10
0
1989
1995
2001
Source: Merom D. Secondary analyses of the National Health Surveys, ABS.
Getting population to be more active
How?
Schools
GPs?
OR ?
Worksites
Changes in health promotion strategy

1986 WHO Ottawa Charter highlighted the
role of the environment in influencing people’s
health.

Creating supportive environments and
building healthy public health policy became
two major health promotion strategies.

Development of ‘ecological’ models to health
promotion in which the environment is
considered as one level of influence.
Changes to physical activity promotion

Much is known about the psychosocial
influences on PA. Less is known about
environmental influences.

Most PA interventions used educational and
cognitive-behavioural approaches aimed at
individuals. They only produce short-term
effect.

Broader approaches are now advocated
–
community-based intervention, use of mass
media and environmental and policy change.
What empirical evidence do we have
to support an ecological approach?

Cross sectional studies (correlates)

Longitudinal studies, including interventions
–
Planned experiments
–
Natural occurrence that has been evaluated
What influences walking / cycling trips?
Transport and urban planning research

High density –

Greater land use mix – relative proximity of different
land uses (shopping, offices
education, within a given
area ).

High Connectivity – The directness and availability
of alternative routes from A to B
(street design)
residential or employment
(persons per acre/ job per acre)
Neighborhoods walkability
Proximity (distance) & Connectivity (directness)
Land use mix, Residential density
Walking / cycling trips among residents of
‘high’ vs. ‘low-walkable’ neighborhoods
Low walkability
3.5
3
N=10
High walkability
3.1
2.6 2.7
N=2
studies
2.5
1.9
2
1.5
1.4
1
0.9
0.7
0.3
0.5
0
total trips
Errands
Exercise
Source: Saelens et al, Ann Behav Med, 2003
work
Public health research adds to
transport research

Broader measures of physical activity (frequency, minutes,
walking purposes), validated for population surveys.

Perceived environment:
Safety (busy road, crime, unattended dogs)
Aesthetic (enjoyable scenery, attractive, pleasant)
Quality of facility (lighting, surface, width)
Convenient of facilities (easy reach, convenient to walk)

Adjusting for individual and social influences on PA
Findings from public health research

Access to facilities (distance / convenience) was
associated with higher usage / higher level of
walking/cycling and total PA .

Aesthetic – In Australia was associated with walking for
exercise but not for travel. In USA only for travel.

Safety – more walking if busy roads, less if unattended
dogs, or feeling unsafe.

Gender differences were noted mainly for safety.

After adjustment to other factors – individual influences
stronger association, necessary but not sufficient
What direction ? (cause and effect)
Environment
?
Physical activity
levels
OR
Choose to live
in supportive
environment,
tend to use
facilities?
?
Physically
active people
PA transfer?
Conceptual model guiding next
generation of research
Factors influencing use
Actual trail/park usage
B
PA
Individual characteristics
Who, how much
E
N
Access to trail/park
Aware?
Trail characteristics
and features
E
Visiting
Other
recreational
activities
F
I
T
S
Information on usage from other organisations
Sydney Urban Park Education and Research Group


Most people visit parks (annually >90% in the
past week 56% )
1/3 to ½ of visitors use the park for active
recreation (mainly walking).
Repeated users?
Already active?
Park users SES, gender age?
Intercept surveys
459 visitors of new trail in WV, USA

78% of trail visitors were ‘regular exercisers’ before
visiting the new trail (3 times per week at least
20min).

Most (90%) of new exercisers reported increased in
PA since using the trail, whereas 48% if regular
exercisers.

New exercisers (22%):
–
–
–
–
–
More likely to travel short distance < 5kms
Used the trail as a primary outlet for PA
More likely to walk, less likely to jog
Convenience was rated as the main reason for use of trail
Unsafe conditions emerged as a concern
A model project - quasi-experimental
(planned experiment)
Community A
T1
Community B
built park/trail
T1
T2
Build park
T2
• Impact - does park development increase PA in the
population (defined) surrounding the park ?
• Process – How often park was used ?
Were ‘users’ already active in T1?
Is it used for active recreation ?
Barriers for not using? (perceived safe,
aesthetics, convenient) but also objective
San Diego Naval military base
Creating supportive environment to enable
integrating physical activity to daily
routine
Quasi-experimental
Pre-post assessments of two cohorts in two
comparable military base
Department of Epidemiology, University of North Carolina
The Naval Health Research Center, San Diego
Source: Linenger et al. Am J Prev. Med, 1998
Environmental and policy changes

Bicycle paths built along roadways

Women’s fitness center opened

Extended hours at recreation facilities

New equipment for gyms

Base-wide athletic events

Running and bicycling clubs organized
Military base - results


Overall fitness score
improved by 16% in the
intervention, significantly
greater than control.
Improved run time in
intervention by 2.4% of the
mean time, significantly
greater than control.
Change among
inactive (% failed test)
Before
25
20.5
17.8
20
15
10
after
12.4
5.1
5

Inactive group benefited the
most (% failed test
dropped)
0
Intervention
Control
Missouri Walking Trails
Community-based intervention using ecological
approach
Prevention of cardio-vascular disease
Quasi-experimental
Two population cross sectional surveys
School of Public Health, Saint Louis University
Division of Chronic Disease Prevention CDC.
Missouri Department of Health
Source: Brownson et al. Am J Prev Med (2000, 2004)
Approach to reducing inactivity

Selecting communities characterized with
no places to walk (no sidewalks, shopping mall).
–
Walking trails were built in residential parks
within city limits, existing trails were upgraded
–
Most (87%) covered with asphalt or gravel
–
mean length – 1km (range 0.25km – 4 kms)
–
Costs between USA $2,000 – $4,000 per trail
Evaluation survey: access, use and effects
(trail existence: mean=1.53 yrs range: ½-5yrs)



36.5% said they had
access to trails in their
area (awareness!!).
Of those who had
access, 40% used the
trail.
55% of trail users
perceived that their
physical activity
increased since use of
trail.
40
36.5
35
Pop. impact
N=1269
30
25
20
15
15
8
10
5
0
Access
Brownson et al. Am J Prev. Med, 2000
Use
Perceived
increase PA
Second stage – promotion of PA
–
Building coalitions: community member, heart
health coalitions, academic partners, local
governments
–
Events: Walk-a-thons, Family Fun Day
–
Walking clubs free of charge
–
Tailored newsletters mailed to individuals.
–
Some community members received swiped card
for tracking their trail use. Data were incorporated
to their newsletter.
Post- intervention evaluation surveys
intervention communities and controls


Overall no net significant
intervention effect on total
walking
Subgroups effect:
–
–
–


Less educated (+15min),
Income < 20,000 (+16min)
Living < 5 miles to trail
Over time, trail use
doubled
Among trail users only
32% reported an increase
in PA since beginning use
18
16
14
12
10
8
6
4
2
0
17
8
8
5
Use
Percieved
increased PA
Pre
Post
The Conversion of Rail-to-Trail
in Western Sydney
Longitudinal design
A population –based sample according to proximity
residents <1.6kms
Only cyclist 1.6-5kms
SWSAHS and WSAHS epidemiology units
Road Traffic Authority (RTA)
NSW Health department
Merom D et al Prev Med. 2002
16kms long
2.5 m wide
Awareness of Trail by target population
Overall 34% who live within 5kms to trail
were aware of the new trail
60
51
50
40
30.1
29.3
Cyclists living
Pedestrians living
Cyclists living 1.6-
<1.6kms
<1.6kms
5kms
% 30
20
10
0
Trail use by target population
25
20.5
20
15
%
10
5
6
3.2
1.6
3.8
0
Change in use
Cyclists
Pedestrians
Cyclists
of trail*
<1.6kms
<1.6kms
1.6-5kms
Change in walking and cycling
No change from pre to
post campaign in
weekly walking minutes

Increase cycling time
(+24mins) among
cyclists from NESB who
live within <1.6kms to
trail.

No change in the
proportion who accrued
‘sufficient’ amount of
walking/cycling.
Increased
walking/cycling of
60mins by trail use
50
40
%

45
30
20
26
10
0
trail User
non-users
20
/1
0
27 /00
/1
0
03 /00
/1
1
10 /00
/1
1
17 /00
/1
1
24 /00
/1
1
01 /00
/1
2
08 /00
/1
2
15 /00
/1
2
22 /00
/1
2
29 /00
/1
2
05 /00
/0
1
12 /01
/0
1
19 /01
/0
1
26 /01
/0
1
02 /01
/0
2
09 /01
/0
2
16 /01
/0
2
23 /01
/0
2
02 /01
/0
3
09 /01
/0
3/
01
24 hours bike counts
Daily bike counts for the period 20/10/00 - 11/03/01 in
selected areas
140
120
Opening day:
Saturday 2/12/00
100
80
60
40
20
0
days
Lessons from intervention studies

Support causal association, but the effect on
population level is small if at all

Over time an increase in usage among those who
were aware of trail or had an access.

Inactive groups, minorities, low SES benefited the
most – reducing inequality.

Usage can help maintaining level of ‘sufficient
activity’ and prevent trend of increased ‘inactivity’.

All interventions required collaboration between
sectors
Challenges for future research

Study design:
–
–
–

Costs compromise design (change over time
within two cohort and multiple measurements).
which population to sample? all ? proximity?
choosing comparison group (matched on SES)
Better measurement:
–
–
unobtrusive new technologies to measure PA
valid common tools for assessing the environment
around and in the facility (audit tools)
Challenges for future research

Identifying and evaluate multiple benefits
– Other outcomes – not only behavior change
social capital, mental health, well being
– community empowerment (can not be measured
by surveys)

Integrating knowledge from all disciplines
–
–
Transport should account for the health context.
Health need to work with communication / marketing
experts on promoting the health benefit of trails/ greenways
Challenges for future interventions

Effective collaboration
–
–
–
Frequent communication at all stages
Agreed objectives across all partners
Clear time line

Need assessments, potential health impact
(e.g., potential for transport?, exercise venue?)

Best practice for promoting trail/park – how to
increase awareness and usage?
Conclusions

There is a great need for well designed
evaluation studies to assess the
effectiveness of environmental change

Currently, it seemed to have an effect on
groups that otherwise would be sedentary

The effects might be seen only at longer term

Multiple outcomes might enhance the
importance of environmental changes
Thank you