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:
Black (n=23) Hispanic (n=31) Variable:bSE b b Total Energy Intake (kcal/d) Total Fat Intake (g/d) The Treatwell 5-a-Day Study – Social Desirability Results by Ethnicity, Women Only White (n=30) bSE b
Non-Professional (n=52) Professional (n=39) Variable:bSE b b Total Energy Intake (kcal/d) Total Fat Intake (g/d) Fruit (servings/d) - FFQ Fruit (servings/1000kcal/d) The Treatwell 5-a-Day Study – Results by Occupational Category, Women Only p-value for Ho:Ho: coll <0.005 <0.05 ns
Less Than College (n=52) College Degree or More (n=39) p-value for H o : coll Total Energy Intake (kcal/d) Total Fat Intake (g/d) Fruit (servings/d) - FFQ Fruit (servings/1000kcal/d) bSE b b Variable: <0.001 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 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):
Overview of Study days Doubly-Labeled Water Metabolic Period Baseline questionnaires Demographic data (education) Social desirability (Marlowe-Crowne Scale, 33-item, true/false) Food frequency questionnaire (WHI)
Married White Pre-menopausal Bachelors Degree or more Employed Full Time Professional, Managerial Work Current Smoker 79.6 Sedentary Description of the Study Population, The Energy Study (N=73) n%
Interquartile Range Mean Standard DeviationMinimum25%75%Maximum Age (years) Body Mass (kg) BMI (kg/m 2 ) Fat-Free Mass (kg) Social Desirability Score Further description of the Study Population, The Energy Study (N=73)
TEE from DLW (kcal/d) Hour Recall-Derived Data (7-day average) Energy Intake (kcal/d) Food Quotient Day-0 Administration Day-14 Administration FFQ Energy (kcal/d) 2102 Interquartile Range MeanStandard DeviationMinimum25%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) (-63.6, -0.2) Excluding “Outliers ” (n=31) Social Desirability Bias (kcal/day/point) by Education Level (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 Whole Sample(n=75) High (n=33) Low (n=42) Education Beginning End Bias (kcal/day/point)
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:
Social Approval Bias in Males, by Education, WATCH Study, Worcester, Massachusetts, < College (n=150) Social Approval Score BMI Baseline Total 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, Worcester, Massachusetts, College (n=70) Social Approval Score BMI 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 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)
College (n=220) Social Approval ScoreBMI Baseline 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 Desirability Score (0.14) (0.34) (0.45) -3.6 (0.77) (0.43) -0.2 (0.97) (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) (0.75) 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, Worcester, Massachusetts,
College (n=64) Social Approval Score BMI Baseline 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 Desirability Score (0.04) (0.07) (0.01) -9.5 (0.54) (0.80) (0.86) -2.9 (0.72) (0.49) (0.52) -5.1 (0.61) (0.67) (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, Worcester, Massachusetts,
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 Psychologic Predispositions Physiologic Responses (e.g., Immune Function) Disease True Diet Reported Diet
Total Fat and Saturated Fat Change in fat intake (% total energy) ±0.38 ±0.14 ±1.36 ±0.49 ±1.39 ±0.50 Total Fat Saturated Fat (n=645) Never Referred< 3 Sessions 3 Sessions WATCH Nutritionist Intervention:
Total Cholesterol and LDL Changes in serum cholesterol (mmol/L) ±0.03 ±0.12 ±0.11 ±0.13 ±0.11 TC LDL-C (n=555) Never Referred< 3 Sessions 3 Sessions WATCH Nutritionist Intervention:
Actual Changes in Total Cholesterol vs. 7DDR - Predicted Values Change in Total Serum Cholesterol (mg/dL) Actual Keys Prediction Hegsted Prediction WATCH Nutritionist Intervention:
Variable P * Self-reported data Fat intake (% energy) Body weight (kg) Measured data Serum LDL-C (mmol/L) Body weight ( kg) Table 4. Effects of social desirability on self- reported and measured change scores, WATCH Study, Worcester, Massachusetts, * P-value for the test of H 0 :=0