A public health perspective on trails and greenways

Towards evidence-based practice

Dafna MeromNSW Centre for Physical Activity and Health

Epidemiological questions

Mental HealthWell being

Chronic disease prevention and control

Health benefits

Physical activity(PA)

Social benefits

Trail / Parks

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

PA CVD CHD

High BP

Obesity

Blood lipids

Total mortality

DiabetesColon cancer

Depression Anxiety, stress

Enhance mood, well being

Bone mass, osteoporosis

Prevent falls

Other cancers?

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)

13.4 13.7 13.114.6 14.6 14.715.3

17.5

13.1

0

5

10

15

20

All Men Women

1997 1999 2000

Source: Bauman et al. Active Australia Surveys, short-term trends

Long-term trend in past week walking for exercise

14.6 14.4 14.7

48.8

52.5

44.6

0

10

20

30

40

50

60

any walking regular walking

1989 1995 2001

Source: Merom D. Secondary analyses of the National Health Surveys, ABS.

Getting population to be more active How?

SchoolsGPs?

Worksites

OR ?

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 – residential or employment (persons per acre/ job per

acre) 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)

Neighborhoods walkability

Proximity (distance) & Connectivity (directness) Land use mix, Residential density

Walking / cycling trips among residents of ‘high’ vs. ‘low-walkable’ neighborhoods

1.4

0.7

2.6

0.3

3.1

1.9

2.7

0.9

0

0.5

1

1.5

2

2.5

3

3.5

total trips Errands Exercise work

Low walkability High walkability

Source: Saelens et al, Ann Behav Med, 2003

N=2 studies

N=10

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)

Physical activity

levels

?

Environment

OR

Physically active people

Choose to live in supportive environment, tend to use facilities?

?

PA transfer?

Conceptual model guiding next generation of research

Factors influencing use

Individual characteristics

Access to trail/parkAware?

Trail characteristicsand features

Visiting

PA Who, how much

Actual trail/park usage

B

E

N

E

F

I

T

S

Otherrecreational

activities

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)

• Impact - does park development increase PA in the population (defined) surrounding the

park ?

Community A

Community B built park/trail

T1

T1Build park

T2

T2

• 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 CarolinaThe 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.

Inactive group benefited the most (% failed test dropped)

Change among inactive (% failed test)

12.4

20.5

5.1

17.8

0

5

10

15

20

25

Intervention Control

Before after

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 UniversityDivision 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.

36.5

15

8

0

5

10

15

20

25

30

35

40

Access Use Perceivedincrease PA

Pop. impactN=1269

Brownson et al. Am J Prev. Med, 2000

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

8 8

17

5

02468

1012141618

Use Percievedincreased PA

Pre Post

The Conversion of Rail-to-Trail in Western Sydney

Longitudinal design

A population –based sample according to proximityresidents <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

51

30.1 29.3

0

10

20

30

40

50

60

Cyclists living

<1.6kms

Pedestrians living

<1.6kms

Cyclists living 1.6-

5kms

%

Overall 34% who live within 5kms to trail were aware of the new trail

Trail use by target population

1.6

20.5

3.2 3.86

0

5

10

15

20

25

Change in use

of trail*

Cyclists

<1.6kms

Pedestrians

<1.6kms

Cyclists

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

26

45

0

10

20

30

40

50

trail User non-users

%

Daily bike counts for the period 20/10/00 - 11/03/01 in selected areas

0

20

40

60

80

100

120

140

days

24 h

ou

rs b

ike

cou

nts

Opening day: Saturday 2/12/00

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