Childhood Obesity Screening and Surveillance

Barbara J. Moore, PhD* Rachel Pahut, RN‡and Mary McCourt, BSW£

*Montana Nutrition and Physical Activity Program‡Marias Medical Center, Shelby, MT

£Missoula City-County Health Department

February 11, 20109:00 – 10:30 AM

barbara.moore@att.net

Topics

• Planning, Safety and Confidentiality• Engaging parents and health care

professionals in the community• What to consider and how to proceed• Measurement protocols• Calculating BMI and plotting age- and

sex-specific BMI percentile

Montana’s Health Ranking

• Since 1990, Montana’s health ranking has steadily declined

• Source: The Future Costs of Obesity (by Thorpe); United Health Foundation, APHA and Partnership for Prevention

Montana’s Health Ranking

• A major factor contributing to our declining overall ranking is Montana’s increase in obesity prevalence

Trends in Obesity Prevalence in U.S. Children

Boys 6-11 y Girls 6-11 y Boys 12-19 y

Girls 12-19 y

0

5

10

15

20

1963-67 1971-74 1976-80 1988-94

1999-2000 2003-2004

%

DATA SOURCE: Ogden JAMA 2002 and Ogden JAMA 2006

Growing % of Pediatric Diabetes is now Type 2 (Obesity-related)

4

20

0

5

10

15

20

25

%1990

2000

<

19902000

Mortality in lean children (BMI quartile 1)vs. heaviest children (BMI quartile 4)Source: Franks et al. NEJM 362(6) Feb. 11, 2010

E. Frongillo, Cornell University and B. J. Moore, Shape Up America!

NHANES III: Data on Major Depression (boys and girls ages 15-19)

0

5.1

2.2

6.6

20.1

6.2

10.38.4

11.1

30.7

0

5

10

15

20

25

30

35

0-5% 5-25% 25-75% 75-95% 95-100%

BMI Percentile Group

%Boys

Girls

Adult Obesity is typically defined by BMI

• BMI is “Body Mass Index”• BMI = weight (kg)/height (m)2

• BMI = [weight (lbs)/height (in)2] X 703• Overweight BMI 25.0 – 29.9• Obesity BMI 30.0 or higher

Pediatric Assessment –BMI Percentile History

• BMI = weight (kg)/height (m)2

• Requires measured height and weight• Plot age-specific and sex-specific BMI

Percentile on CDC growth chart (2000)• ≥85th - <95th percentile = “overweight”• ≥95th percentile = “obese”

Reference Population of 5 year old females

95th5th

50th Percentile

85th

CDC Growth Charts - BMI

95th

85th

50th

5th

95th

85th

50th

5th

Reference Population of 5 year old females

95th5th

50th Percentile

85th

BMI declines until age 3 – 5; then BMI increases thereafter

Age BMI 2 yrs 19.3 4 yrs 17.8 9 yrs 21.013 yrs 25.1

For Children, BMI Differs by Age and Sex

Boys: 2 to 20 years

BMI BMI

BMI BMI

95th

85th

50th

5th

85th

75th

For this 10 yearold girl witha BMI of 19.3,her BMI Percentile falls between the 75th and 85th percentile lines(normal weight)

85th

75th

But 2 ½ years later, her BMI Percentile is above the 90th percentile soshe is now categorizedas “overweight” ANDHer BMI trajectory is clearly upward(i.e. NOT tracking close to the75th percentile)

90th

95th

Example: 95th Percentile Tracking

Age BMI 2 yrs 19.3 4 yrs 17.8 9 yrs 21.013 yrs 25.1

Is this boy obese?

Boys: 2 to 20 years

BMI BMI

BMI BMI

Growth Charts

• “Children's Growth Charts Don't Measure Up With Parents”

• Many don't understand how to read or interpret them, survey shows

• You can help!

In a normal population of 300 children …

How many would you expect to meet the definition of “obese”?

5%

15 children

Obesity is defined by the 95th percentile so only 5% would be

expected to be obese.

Childhood Obesity in Preschoolers, by Ethnicity

American Indian

Hispanic Black White Asian0

5

10

15

20

25

30

35

% Obese

Anderson & Whitaker Arch Pediatr Adolesc Med 2009;163(4):344-348

%

Costs of Childhood Obesity –$15 billion (2004)

“Children treated for obesity are roughly three times more expensive for

the health system than the average insured child”

Much higher rates of comorbidities

>3X higher hospitalization rates

2X physician visit rates

Risk of Childhood Obesity Increases if

One or Both Parents Obese

0

2

4

6

8

10

12

MaternalPaternalBoth

Vicious Cycle

More obese children aregrowing up to be obese adults

and obese parents.

Their children are more likely to be obese

What can be done to break the cycle ?

Preventing Childhood Obesity:

Health in the Balance

Institute of Medicine

2005

School-based BMI programs

• Screening programs measure children to identify those at risk

• Send confidential letters home to parents on BMI status of child

• Encourage referral to local professionals if appropriate for more thorough evaluation

• Expensive but good for prevention

U.S. Preventive Services Task Force (USPSTF) January 2010 Recommendation Statement on

Screening for Obesity in Children and Adolescents

The USPSTF recommends that clinicians screen children aged 6 years and older for obesity and

offer them or refer them to comprehensive, intensive behavioral interventions to promote

improvement in weight status.

Grade: B recommendation.

See also: Pediatrics in January 2010 (Pediatrics 2010;125:361-367. http://www.pediatrics.org).

School-based BMI programs

• Surveillance programs measure children and calculate percentages of overweight and obesity at each grade level (and by sex) to assess health, inform policy and track progress

• Can be limited to a single grade level or to two or more grade levels

• Provide a “snapshot” on health status

Planning• Funding for equipment and staff• School Nurse(s)• Orientation and Training of Staff• Wellness Committee • Parents involved/supportive• Local Health Care Professionals alerted• Data handling and storage

Safety

• Respect for students (↓trauma ↓stigma)• Accurate data• Clean, private setting for measurements• Discourage comparing numbers• Be alert to anxiety (heaviest girls and

boys small-for-age)• Permit opt-out (?)

– Parent– Student

Confidentiality

• Think of how you will use and analyze the data, store it and maintain it in a safe place

• Store for years if screening; matching• Disclose only to parent(s) or legal

guardian(s)• Special circumstances (teen) ?

What to consider?

• Screening vs. Surveillance• What do you want the data for?• Budget constraints• Alerting parents they may opt out

– Passive vs. Active• Alerting and engaging local health

providers (prepare for referrals)

School Wellness Committee

• Can help garner support for screening and/or surveillance of children

• Committee members: school nurse, food service personnel, administrators, teachers, parents, students and local health care professionals

How to Proceed

• Train staff• Choose and calibrate equipment• Adopt protocols for height and weight

measures (test and re-test)• Agree on dates, place and time(s)• Establish process for data collection,

analysis and storage• Prepare reports and communicate

results

Height Protocol

Height Protocol

• Errors in height measures are squared• Consult the CDC website and training

resources• Research various stadiometers and

select the best equipment your budget permits

• If student body is large, this is essential

Height Protocol

• Think about straight lines and right angles

• Use ONLY a clinical quality stadiometer to measure height

• (QuickMedical.com; model 31-420)

Height Protocol

• Measure to nearest 0.1 cm (or 1/8 inch) and record value

• Repeat measurement, having the child line up again, and record appropriate value immediately on data form.

• Repeat measurements should agree within ½ cm or ¼ inch, if they do not, repeat measurement a third time.

Weight Protocol

• Consult the CDC website and training resources

• Research various scales and select the best equipment your budget permits

• Select scale that is durable • Detachable readout is recommended• Measure in metric units (confidentiality)

Weight Protocol(Tanita.com)

Recording Data

• Do you need a recorder?• Date of birth?• Record sex/gender• Screening data year to year ?• Matching up student’s data next year?• ID numbers for students?• Record directly into Excel?

Calculations

• Use the CDC Excel Spreadsheet• Checks for error messages/bad data• Calculates data AND summarizes the

data automatically• Graphs your data by grade level if you

use a separate spreadsheet for each grade

The Link to the CDC Spreadsheets

(English and Metric)

http://www.cdc.gov/healthyweight/assessing/bmi/

childrens_BMI/tool_for_schools.html

Measurements (Metric vs. English)

Measurements

Group Summary

Group Summary

Resources – Missoulawww.co.missoula.mt.us/measures/PDF/BMIReport08.pdf Contact Mary McCourt at McCourtM@ho.missoula.mt.us

Resources - Massachusetts

• Includes guidelines for measuring non-ambulatory students

• To be revised in 2010

Resources - Arkansas

• www.ACHI.net• Arkansas

measured all children in the state (now alternate grades)

• Procedures well established

Resources - Arkansas

Resources – Ohio(www.odh.ohio.gov/ASSETS/.../bmiguidlines_0607.pdf)

Resources - Wisconsin http://dhs.wisconsin.gov/health/physicalactivity/Sites/School/To_Weigh_Measure.pdf

Background Reading

http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5817a3.htm?s_cid=mm5817a3_e

Florida: Assessment of Body Mass Index Screening of Elementary School Children --- Florida, 2007—2008

MMWR May 8, 2009 / 58(17);460-463

Background Reading

Nihiser AJ, Lee SM, Wechsler H, McKenna M, Odom E, Reinold C, Thompson D, Grummer-Strawn L. Body mass index measurement in schools.

J Sch Health. 2007; 77: 651-671.

(see CDC website to download a copy)

QUESTIONS?