Real World Evaluation of Physical Activity Using Objective Monitors

Catrine Tudor-Locke, PhD, FACSMAssociate Professor Director, Walking Behavior LaboratoryPennington Biomedical Research CenterBaton Rouge, Louisiana

Real world evaluation of physical activity using objective monitors Key distinctions between research and

evaluation Which instrument is best? Practical pedometry

Expected values Step indices

Key distinctions between research and evaluation: Purpose Research

Advances scholarly knowledge

Review by peers Is published

Evaluation Provides timely

information for decision making

Answers to stakeholders Has practical utility

Key distinctions between research and evaluation: Focus Research

Examines efficacy under highly controlled, artificial conditions

Subjects are carefully selected

Has strict inclusion, exclusion criteria

Evaluation Examines effectiveness

and efficiency under real-world conditions

Participants are self-selected

No restrictions

Key distinctions between research and evaluation: Methods Research

Rigorous methodologies Research assistants

collect data Batteries of tests Significant group

differences

Evaluation Good enough

methodologies Staff and volunteers

collect data Practical assessments Relative client benefits

(% improving)

Which instrument is best??

Yamax Corporation, Tokyo, JapanCost: US$17-22

Raw Outputs:

Steps

Derived Outputs:

Steps/day

Steps/min

Yamax pedometer- SW Series

ActiGraph

ActiGraph, LLC,; Pensacola, FLCost: US$325/unitUS$349 Cable/software

Raw Outputs:

Steps

Activity Counts

Time in intensity categories

Energy expenditure

NL-1000

New-Lifestyles, Inc., Lee Summit, MOCost: US$48

Raw Outputs:Steps

Distance

Time in MVPA

activPAL Professional

PAL Technologies, LTD, Glasgow

Cost: Initially $US1450Software, docking station, unit$US950 additional units

Outputs:Steps

Time in sitting, standing, ambulating

Transitions

Sit/stand bouts

Energy expenditure

What I Do and Do Not Know Now What I know now Commercial items Patents Change Buyer beware Choose, rationalize,

and justify your own choice

What I don’t know The best instrument

for all situations How well they

translate Obsolescence Future

Summary of validity evidence

Review of 25 articles since 1980 median r=.86 with

different accelerometers median r=.82 with time in

observed activity median r=.68 with

different measures of energy expenditure

median r=-.38 with self-reported sitting time

median r=.33 with self-reported physical activity

Tudor-Locke et al., Sports Med 2002

Pedometers

Accelerometers

Self-reported physical activity

Energy Expenditure

Practical Pedometry

Expected values Standard protocols Screening Surveillance Program evaluation Step indices Intervention tool

0

2000

4000

6000

8000

10000

12000

14000

Mean steps/day

1 2 3 4 5Population groups

Legend

1=8-10 year olds

2=14-16 year olds

3= Healthy younger adults (approx. 20-50 years)

4= Healthy older adults (>50 years)

5= Individuals living with disabilities and chronic illnesses

Tudor-Locke, Research Digest, 2002

0

2

4

6

8

10

12

14

0-99

9

1000

-199

9

2000

-299

9

3000

-399

9

4000

-499

9

5000

-599

9

6000

-699

9

7000

-799

9

8000

-899

9

9000

-999

9

1000

0-10

999

1100

0-11

999

1200

0-12

999

1300

0-13

999

1400

0-14

999

1500

0-15

999

1600

0-16

999

1700

0-17

999

1800

0-18

999

1900

0-19

999

Mean Steps/Day

Perc

ent

Normative data

Tudor-Locke et al., Medicine and Science in Sport and Exercise, 2004

Normative data

Expected values for special populations

0

2,000

4,000

6,000

8,000

10,000

12,000

Heart and

Vas

cular

Dise

ases

(15)

COPD (2)

Type 2

diabete

s (11

)

Type 1

diabete

s (1)

Dialysis

(1)

Breast

Cance

r Surv

ivor (9

)

Breast

Cance

r in Trea

tmen

t (1)

Neuromusc

ular D

iseas

es (3

)

Arthriti

s (2)

Joint

Rep

lacem

ent (9

)

Fibromya

lgia (

1)

Disable

d Older

Adults (

2)

Intell

ectua

l Disa

bility

(4)

HIV (4

)

Multiple

Chronic

Illnes

s (1)

Tudor-Locke et al., Preventive Medicine, 2009

CANPLAY data

Craig et al., MSSE, under review

0

2

4

6

8

10

12

14

0-99

9

1000

-199

9

2000

-299

9

3000

-399

9

4000

-499

9

5000

-599

9

6000

-699

9

7000

-799

9

8000

-899

9

9000

-999

9

1000

0-10

999

1100

0-11

999

1200

0-12

999

1300

0-13

999

1400

0-14

999

1500

0-15

999

1600

0-16

999

1700

0-17

999

1800

0-18

999

1900

0-19

999

Mean Steps/Day

Per

cent

Normative values for free-living youth

10000

11000

12000

13000

14000

15000

16000

17000

6 7 8 9 10 11 12 13 14 15 16 17 18

Age in years

Med

ian

step

s/da

y

BoysGirls

Tudor-Locke et al., Research Quarterly for Exercise and Sport, 2009

Tudor-Locke et al., Medicine and Science in Sports and Exercise, in press

Time

T4T3

W8W7

W6W5

T2W4

W3W2

W1T1

Ave

rage

ste

ps/d

ay

14,000

12,000

10,000

8,000

6,000

4,000

Tudor-Locke et al., Patient Education and Counseling, 2002

Meta-analysis of change in steps/day in pedometer-based programming

Bravata et al., JAMA, 2007

12,500+ steps/day

10,000-12,499 steps/day

7,500-9,999 steps/day

5,000-7,499 steps/day

2,500-4,999 steps/day

<2,500 steps/day Basal

Activity

Limited Activity

Low Active

Somewhat Active

Active

Highly Active

Sedentary Lifestyle

Graduated Step IndexAdapted from Tudor-Locke and Bassett, 2004and Tudor-Locke et al., 2009

Pedometer-determined step guidelines for children (6-12 years of age)

Boys >17000 steps/day

highly active 15000-17999 steps/day

active 12500-14999 steps/day

somewhat active 10000-12499 steps/day

low active <10000 steps/day

sedentary

Girls >14500 steps/day

highly active 12000-14999 steps/day

active 9500-11999 steps/day

somewhat active 7000-9499 steps/day

low active <7000 steps/day

sedentary

Tudor-Locke et al., MSSE, 2008

18000

17000

16000

15000

14000

13000

12000

11000

10000

9000

8000

7000

6000

5000

4000

3000

2000

1000

0

Boys 6-11 years

Girls 6-11 years

Adults 20-65 years

Individuals living with disability and/or chronic illness

Youth 12-19 yearsPre-school

children4-6 years

At least 6,000 daily steps in moderate-to-vigorous physical activity

At least 15,000 steps/week in moderate-to-vigorous

physical activity, e.g., 3,000 daily steps in moderate-to-vigorous physical activity

most days of the week

Arrows indicate that higher is even better

Step

s/da

y

Healthy older adults 65+ years

Additional benefits can come from adding in vigorous intensity activityTudor-Locke et al., in progress

Thank you!