The Treatwell 5-a-Day Study Multi-ethnic sample of community health center workers Representing three control sites Multiple 24HR as “relative criterion”

The Treatwell 5-a-Day Study

Multi-ethnic sample of community health center workers

Representing three control sites

Multiple 24HR as “relative criterion”

Uses three methods for comparison, including Harvard/Channing FFQ

Predominantly (~85% women)

Hebert JR, Peterson KE, Hurley TG, Stoddard AM, Cohen N, Field AE, Sorensen G. The effect of social desirability trait on self-reported dietary measures among multi-ethnic female health center employees. Ann Epidemiol 2001; 11:417-427.

Black(n=23)

Hispanic(n=31)

Variable: b SEb b SEb

Total Energy Intake (kcal/d) 15.1 31.1 18.9 20.0

Total Fat Intake (g/d) 0.64 0.94 1.03 1.07

The Treatwell 5-a-Day Study – Social Desirability Results by Ethnicity,

Women Only

White(n=30)b SEb

-4.5 15.9

-0.23 0.62

Non-Professional

(n=52)

Professional

(n=39)Variable: b SEb b SEb

Total Energy Intake (kcal/d) 31.8 18.5 -20.6 14.5

Total Fat Intake (g/d) 1.12 0.67 -0.19 0.57

Fruit (servings/d) - FFQ 0.011 0.042 -0.004 0.037

Fruit (servings/1000kcal/d) -0.008 0.031 0.002 0.029

The Treatwell 5-a-Day Study – Results by Occupational Category, Women Only

p-value for

Ho: <coll>coll

<0.005

<0.05

ns

ns

Less Than College(n=52)

College Degree or More(n=39)

p-value for

H o: <coll>coll

Total Energy Intake (kcal/d) 36.1 20.0 -23.6 12.8

Total Fat Intake (g/d) 1.23 0.78 -0.50 0.41

Fruit (servings/d) - FFQ -0.003 0.046 -0.027 0.033

Fruit (servings/1000kcal/d) -0.005 0.032 -0.002 0.026

b SEb b SEbVariable:

<0.001

<0.001

ns

ns

The Treatwell 5-a-Day Study – Results by Education, Women Only

The Treatwell 5-a-Day Study – Conclusions

The FFQ also appears to be biased by social desirability in women, but …..

the critical factor determining the bias is education which is …..

more important than occupational category or ethnicity/race.

As in the WATCH study, bias is oriented toward fat/energy intake

The Energy Study, Worcester, MA - 1997

First such study to focus on the most widely used FFQ (NCI/WHI)

First study to focus on these biases employing stable isotope methods for comparison (TEE from DLW)

Hebert JR, Ebbeling CB, Matthews CE, Ma Y, Clemow L, Hurley TG, Druker S. Systematic errors in middle-aged women's estimates of energy intake: Comparing three self-report measures to total energy expenditure from doubly labeled water. Ann Epidemiol 2001; (In Press):00-000.

Overview of Study

days

0 71 14

Doubly-Labeled Water Metabolic Period

Baseline questionnaires

Demographic data (education)

Social desirability (Marlowe-Crowne Scale, 33-item, true/false)

Food frequency questionnaire (WHI)

Married 47 64.4White 72 98.6Pre-menopausal 41 56.2Bachelors Degree or more 33 45.2Employed Full Time 44 60.3Professional, Managerial Work 33 55.0Current Smoker 7 9.6Sedentary 38 52.1

Description of the Study Population, The Energy Study (N=73)

n %

InterquartileRange

Mean StandardDeviation Minimum25% 75% Maximum

Age (years) 49.0 6.8 40 44 53 65

Body Mass (kg) 70.0 10.4 43.9 62.1 76.9 90.5

BMI (kg/m2) 27.1 4.1 18.7 24.5 29.8 38.2

Fat-Free Mass (kg) 42.4 5.1 32.3 38.1 46.3 53.7

Social Desirability Score

17.4 5.9 4.0 15.0 22.0 29.0

Further description of the Study Population, The Energy Study (N=73)

TEE from DLW (kcal/d) 380 1378 1830 2318 3337

24-Hour Recall-DerivedData (7-day average)Energy Intake (kcal/d) 1820 464 1147 1494 2002 3566Food Quotient 0.90 0.03 0.82 0.88 0.92 0.99

Day-0 Administration 1735 764 429 1229 2089 4986Day-14 Administration 1622 594 639 1186 2028 3703

FFQ Energy (kcal/d)

2102

InterquartileRange

Mean StandardDeviation Minimum 25% 75% Maximum

Further description of the Study Population, The Energy Study (N=73)

All Education Levels: Whole Sample (n=73) -36.6 (-65.7, -7.5)

Excluding “Outliers ” (n=69) -12.2 (-34.7, 13.1)

High Education (college +) Whole Sample (n=33) -73.3 (-113., -32.9)

-31.9 (-63.6, -0.2) Excluding “Outliers ” (n=31)

Social Desirability Bias (kcal/day/point) by EducationLevel (FFQ-Derived Energy Intake Versus TEE from

DLW, Beginning of Metabolic Period), The Energy Study (N=73).

All Education Levels: Whole Sample (n=73) -10.8 (-34.7, 13.1)

Excluding “Outliers ” (n=72) -13.7 (-35.8, 8.4)

High Education (college +) Whole Sample (n=33) -21.8 (-53.5, 9.9)

Social Desirability Bias (kcal/day/point) by Education Level (FFQ-Derived Energy Intake Versus TEE from DLW, End of Metabolic Period), The Energy Study

(N=73).

Social Desirability Bias

-150

-125

-100

-75

-50

-25

0

25

50

WholeSample(n=75) High

(n=33)Low

(n=42)

Education

Beginning

End

Bia

s (k

cal/d

ay/p

oint

)

Revisiting WATCH --- Why?

Is there an effect of education when cut at college+?

What happens with these biases after an intervention?

Hebert JR, Ma Y, Ebbeling CB, Matthews CE, Ockene IS. Self-report data. Compliance in Healthcare and Research. Armonk, NY: Futura, 2001:163-179.

Social Approval Bias in Males, by Education, WATCH Study,

Worcester, Massachusetts, 1991-1995.

< College (n=150)Social Approval

Score BMI

BaselineTotal Energy (kcal/day) 29.8 (0.003) 29.1 (0.07)

Total Fat (g/day) 1.63 (0.004) 1.60 (0.07)Total SFA (g/day) 0.59 (0.003) 0.53 (0.09)One-year < College (n=112)

Total Energy (kcal/day) 36.7 (0.0003) 53.4 (0.001)Total Fat (g/day) 1.50 (0.004) 1.72 (0.04)Total SFA (g/day) 0.41 (0.02) 0.57 (0.05)

Social Approval Bias in Males, by Education, WATCH Study,


College (n=70)Social Approval

Score BMIBaseline

Total Energy (kcal/day) 8.6 (0.49) 48.6 (0.05)Total Fat (g/day) 0.58 (0.39) 3.87 (0.05)

Total SFA (g/day) 0.26 (0.26) 1.34 (0.07)One-year College (n=56)

Total Energy (kcal/day) 19.9 (0.14) 33.7 (0.14)Total Fat (g/day) 1.05 (0.11) 0.70 (0.52)

Total SFA (g/day) 0.25 (0.18) 0.15 (0.63)


Score BMIBaseline

Total Energy (kcal/day)Total Fat (g/day)Total SFA (g/day)One-year College (n=172)

Total Energy (kcal/day)

Total Fat (g/day)Total SFA (g/day)

Social DesirabilityScore

-14.8 (0.14)-0.53 (0.34)-0.14 (0.45)

-3.6 (0.77)

-0.57 (0.43)

-0.2 (0.97)-0.02 (0.95)0.03 (0.76)

11.0 (0.07)

0.36 (0.32)0.14 (0.21)

6.9 (0.43)0.25 (0.61)0.05 (0.75)

11.1 (0.32)

0.36 (0.58)0.21 (0.32)-0.15 (0.52)

Social Approval and Social Desirability Bias in Females, by Education, WATCH Study,



Score BMIBaseline

Total Energy (kcal/day)Total Fat (g/day)Total SFA (g/day)One-year College (n=53)

Total Energy (kcal/day)

Total Fat (g/day)

Total SFA (g/day)

Social DesirabilityScore

-24.3 (0.04)-1.28 (0.07)

-0.53 (0.01)

-9.5 (0.54)

-0.21 (0.80)

-0.05 (0.86)

-2.9 (0.72)-0.34 (0.49)-0.10 (0.52)

-5.1 (0.61)

-0.23 (0.67)

-0.06 (0.74)

19.7 (0.11)1.42 (0.05)

0.41 (0.07)

35.5 (0.04)

1.98 (0.02)

0.75 (0.01)

Social Approval and Social Desirability Bias in Females, by Education, WATCH Study,


WATCH Study Conclusions:

Education modifies the effect of the social desirability and social approval

The effects differ by gender

There appears to be a differential effect of the intervention on the bias according to gender and education

The Role of Social Desirability in Epidemiologic Confounding

SD Score PsychologicPredispositions

PhysiologicResponses(e.g., ImmuneFunction)

Disease

TrueDiet

ReportedDiet

Total Fat and Saturated Fat

-12

-10

-8

-6

-4

-2

0

Cha

nge

in f

at in

take

(% to

tal e

nerg

y)

-0.71 -0.26 -4.95 -2.13 -8.24 -2.73

±0.38±0.14

±1.36

±0.49

±1.39

±0.50

Total FatSaturated Fat

(n=645)

Never Referred < 3 Sessions3 Sessions

WATCH Nutritionist Intervention:

Total Cholesterol and LDL

-0.75

-0.6

-0.45

-0.3

-0.15

0

0.15

Cha

nges

in s

erum

cho

lest

erol

(m

mol

/L)

0.01-0.02 -0.15 -0.13 -0.43 -0.48±0.03

±0.03

±0.12 ±0.11

±0.13 ±0.11TCLDL-C

(n=555)

Never Referred < 3 Sessions3 Sessions


Actual Changes in Total Cholesterol vs. 7DDR - Predicted Values

-10-9-8-7-6-5-4-3-2-10

-9.9 -8.4 -9.1

Cha

nge

in T

otal

Ser

um C

hole

ster

ol

(mg/

dL)

ActualKeys Prediction

Hegsted Prediction


Variable P *

Self-reported data Fat intake (% energy) -0.22 0.002

Body weight (kg) -0.02 0.59

Measured data

Serum LDL-C (mmol/L) 0.004 0.48

Body weight (kg) 0.02 0.59

Table 4. Effects of social desirability on self-reported and measured change scores, WATCH

Study, Worcester, Massachusetts, 1991-1995.

* P-value for the test of H0:=0

The Treatwell 5-a-Day Study Multi-ethnic sample of community health center workers Representing three control sites Multiple 24HR as “relative criterion”

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