The Treatwell 5-a-Day Study

1
The Treatwell 5-a-Day Study
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 11417-427.

• 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)

2
The Treatwell 5-a-Day Study Social Desirability
Results by Ethnicity, Women Only
Black
Hispanic
White
(n23)
(n31)
(n30)
Variable
b
SEb
b
SEb
b
SEb
Total Energy Intake (kcal/d)
15.1
31.1
18.9
20.0
-4.5
15.9
Total Fat Intake (g/d)
0.64
0.94
1.03
1.07
-0.23
0.62
3
The Treatwell 5-a-Day Study Results by
Occupational Category, Women Only
Non-Professional
Professional
p-value for
(n52)
(n39)
Ho
bltcollbgtcoll
Variable
b
SEb
b
SEb
Total Energy Intake (kcal/d)
31.8
18.5
-20.6
14.5
lt0.005
0.57
Total Fat Intake (g/d)
1.12
0.67
-0.19
lt0.05
ns
0.037
Fruit (servings/d) - FFQ
0.011
0.042
-0.004
Fruit (servings/1000kcal/d)
-0.008
0.031
0.002
0.029
ns
4
The Treatwell 5-a-Day Study Results by
Education, Women Only
College Degree or More
p-value for
Less Than College
(n52)
H o
bltcollbgtcoll
(n39)
b
SEb
b
SEb
Variable
Total Energy Intake (kcal/d)
36.1
20.0
-23.6
12.8
lt0.001
Total Fat Intake (g/d)
1.23
0.78
-0.50
0.41
lt0.001
Fruit (servings/d) - FFQ
-0.003
0.046
-0.027
0.033
ns
Fruit (servings/1000kcal/d)
-0.005
0.032
-0.002
0.026
ns
5
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
6
The Energy Study, Worcester, MA - 1997
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.

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)
7
Overview of Study
Doubly-Labeled Water Metabolic Period
7
14
0
1
days

• Baseline questionnaires
• Demographic data
• (education)
• Social desirability (Marlowe-Crowne Scale,
  33-item, true/false)
• Food frequency questionnaire
• (WHI)

8
Description of the Study Population, The Energy
Study (N73)
n

Married
47
64.4
White
72
98.6
Pre-menopausal
41
56.2
Bachelors Degree or more
33
45.2
Employed Full Time
44
60.3
Professional, Managerial Work
33
55.0
Current Smoker
7
9.6
Sedentary
38
52.1
9
Further description of the Study Population, The
Energy Study (N73)
Interquartile
Range
Mean
Standard
Deviation
Minimum
25
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
10
Further description of the Study Population, The
Energy Study (N73)
Interquartile
Range
Mean
Standard
Deviation
Minimum
25
75
Maximum
380
1378
1830
2318
3337
TEE from DLW (kcal/d)
2102
24-Hour Recall-Derived
Data (7-day average)
Energy Intake (kcal/d)
1820
464
1147
1494
2002
3566
Food Quotient
0.90
0.03
0.82
0.88
0.92
0.99
FFQ Energy (kcal/d)
Day-0 Administration
1735
764
429
1229
2089
4986
Day-14 Administration
1622
594
639
1186
2028
3703
11
Social Desirability Bias (kcal/day/point) by
Education Level (FFQ-Derived Energy Intake Versus
TEE from DLW, Beginning of Metabolic Period),
The Energy Study (N73).
All Education Levels
Whole Sample (n73)
-36.6 (-65.7, -7.5)
Excluding Outliers (n69)
-12.2 (-34.7, 13.1)
High Education (college )
Whole Sample (n33)
-73.3 (-113., -32.9)
-31.9 (-63.6, -0.2)
Excluding Outliers (n31)
12
Social Desirability Bias (kcal/day/point) by
Education Level (FFQ-Derived Energy Intake Versus
TEE from DLW, End of Metabolic Period), The
Energy Study (N73).
All Education Levels
Whole Sample (n73)
-10.8 (-34.7, 13.1)
Excluding Outliers (n72)
-13.7 (-35.8, 8.4)
High Education (college )
Whole Sample (n33)
-21.8 (-53.5, 9.9)
13
Social Desirability Bias
50
25
0
-25
Bias (kcal/day/point)
-50
-75
Beginning
-100
End
-125
-150
Education
Whole Sample(n75)
High (n33)
Low (n42)
14
Revisiting WATCH --- Why?
Hebert JR, Ma Y, Ebbeling CB, Matthews CE, Ockene
IS. Self-report data. Compliance in Healthcare
and Research. Armonk, NY Futura, 2001163-179.

Is there an effect of education when cut at
college?

What happens with these biases after an
intervention?
15
Social Approval Bias in Males, by Education,
WATCH Study, Worcester, Massachusetts,
1991-1995.
lt College (n150)
Social Approval
BMI
Score
Baseline
29.8 (0.003)
29.1 (0.07)
Total Energy (kcal/day)
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
lt College (n112)
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)
16
Social Approval Bias in Males, by Education,
WATCH Study, Worcester, Massachusetts,
1991-1995.
³ College (n70)
Social Approval
BMI
Score
Baseline
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
³ College (n56)
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)
17
Social Approval and Social Desirability Bias in
Females, by Education, WATCH Study, Worcester,
Massachusetts, 1991-1995.
lt College (n220)
Social Approval
Social Desirability
Score
BMI
Score
Baseline
Total Energy (kcal/day)
-14.8 (0.14)
-0.2 (0.97)
6.9 (0.43)
Total Fat (g/day)
-0.53 (0.34)
-0.02 (0.95)
0.25 (0.61)
0.05 (0.75)
Total SFA (g/day)
-0.14 (0.45)
0.03 (0.76)
One-year
lt College (n172)
Total Energy (kcal/day)
-3.6 (0.77)
11.0 (0.07)
11.1 (0.32)
Total Fat (g/day)
-0.57 (0.43)
0.36 (0.32)
0.36 (0.58)
Total SFA (g/day)
0.14 (0.21)
0.21 (0.32)
-0.15 (0.52)
18
Social Approval and Social Desirability Bias in
Females, by Education, WATCH Study, Worcester,
Massachusetts, 1991-1995.
³ College (n64)
Social Approval
Social Desirability
Score
Score
BMI
Baseline
Total Energy (kcal/day)
-24.3 (0.04)
-2.9 (0.72)
19.7 (0.11)
Total Fat (g/day)
-1.28 (0.07)
-0.34 (0.49)
1.42 (0.05)
Total SFA (g/day)
-0.53 (0.01)
-0.10 (0.52)
0.41 (0.07)
One-year
³ College (n53)
Total Energy (kcal/day)
-9.5 (0.54)
-5.1 (0.61)
35.5 (0.04)
Total Fat (g/day)
-0.21 (0.80)
-0.23 (0.67)
1.98 (0.02)
Total SFA (g/day)
-0.05 (0.86)
-0.06 (0.74)
0.75 (0.01)
19
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

20
The Role of Social Desirability in Epidemiologic
Confounding
SD Score
Psychologic Predispositions
Physiologic Responses (e.g., Immune Function)
Disease
True Diet
Reported Diet
21
WATCH Nutritionist Intervention
Total Fat and Saturated Fat
Never Referred
lt 3 Sessions
³ 3 Sessions
-0.71
-0.26
-4.95
-2.13
-8.24
-2.73
0
0.14
-2
0.38
0.49
-4
0.50
( total energy)
-6
Change in fat intake
1.36
-8
Total Fat
-10
1.39
Saturated Fat
(n645)
-12
22
WATCH Nutritionist Intervention
Total Cholesterol and LDL
Never Referred
lt 3 Sessions
³ 3 Sessions
0.01
0.15
0.03
-0.02
-0.15
-0.13
-0.43
-0.48
0
0.03
-0.15
Changes in serum cholesterol (mmol/L)
0.11
0.12
-0.3
-0.45
TC
0.13
-0.6
0.11
LDL-C
-0.75
(n555)
23
WATCH Nutritionist Intervention
Actual Changes in Total Cholesterol vs. 7DDR -
Predicted Values
0
-9.9
-8.4
-9.1
-1
-2
-3
-4
Change in Total Serum Cholesterol
(mg/dL)
-5
-6
-7
-8
-9
Keys Prediction
Hegsted Prediction
-10
Actual
24
Table 4. Effects of social desirability on
self-reported and measured change scores, WATCH
Study, Worcester, Massachusetts, 1991-1995.

Variable
P
b
Self-reported data

Fat intake ( energy)
-0.22
0.002
Body weight
-0.02
0.59
(kg)
Measured data

Serum LDL-C (mmol/L)
0.004
0.48

Body weight
0.02
0.59
(kg)

P-value for the test of H00