Multifactor Screener: Scoring Procedures
How Analytical Scoring Procedures Were Developed
Scoring procedures were developed to convert a respondent's screener responses to
estimates of individual dietary intake for percentage energy from fat, grams of fiber, and servings
of fruits and vegetables, using USDA's
1994-96 Continuing Survey of
Food Intakes of Individuals (CSFII 94-96) dietary recall data. The following equations
were estimated in the CSFII 94-96:
For percentage energy from fat and fiber:
E(Dietary Factor) = b0+ b1NFG1P1
+ b2NFG2P2
+ ... + b20NFG20P20
E(Dietary Factor) indicates the expected values for percentage energy from
fat and for fiber, and assumes a normal distribution. In the CSFII 94-96
dataset percentage energy from fat was normally distributed. However, fiber
was positively skewed and required a cube-root transformation to approximate
normality. NFGk is the usual number of times
per day an individual consumed food group k; Pk
is the median portion size of group k; and k indexes the 20 food groups.
These 20 food groups were formed to reflect the same food groups on the
screener. We calculated weighted least-squares estimates of the regression
coefficients bk, k = 0, ..., 20 on CSFII 94-96
adults aged 18 and above, stratifying by gender and excluding extreme
exposure values. We first included all 20 food groups in the regression
model. After examining the results, we dropped food groups that failed
to attain statistical significance at the α = 0.25 level to form more
parsimonious final models. In both the percentage energy from fat model and
the fiber model, the lettuce food group was dropped. Because of the complex
survey design, the analysis was performed using
SUDAAN (RTI Inc., Research Triangle Park, NC).
For Pyramid servings of fruits and vegetables
(defined by USDA in the 1992 Dietary Guidelines Food Guide Pyramid):
E(Fruits and Veg1/2) = b0 + b1
(NFG1P1 + NFG2P2
+ ... + NFG7P7)1/2
Pyramid servings of fruits and vegetables was square-root-transformed to approximate
normality; NFGk is the usual number of times
per day an individual consumed food group k; Pk
is the median portion size of group k; and k indexes the 7 fruit and vegetable
food groups. We calculated weighted least-squares estimates of the regression
coefficients b0 and b1
on the adults in the CSFII 94-96 sample, stratifying by gender and excluding
extreme exposure values.
Scoring Procedures
After exclusion of extreme and missing values, we performed the following
steps with the Cancer Control Supplement dietary data to estimate the individual's intake of
servings of fruits and vegetables, percent energy from fat, and fiber.
- Estimation of NFGk: All reported
frequencies were standardized to a common unit of time by converting
them to daily frequencies.
| Time Period Reported |
NFGk: Daily
Frequency |
| Day |
As reported |
| Week |
Reported frequency divided by 7 |
| Month |
Reported frequency divided by 30 |
| Year |
Reported frequency divided by 365 |
- Estimation of Pk: The median age-
and gender-specific portion sizes for each food were estimated from
CSFII 94-96. For percent energy from fat and fiber variables, the units
were in grams (Tables 1-2); for fruit and vegetable servings variables,
the units were in Pyramid servings (Table 3).
A Pyramid serving is defined by the U.S. Department of Agriculture
in the Dietary Guidelines
Food Guide Pyramid (used from 1992-2004) as:
- vegetables: 1 cup raw leafy, 1/2 cup of other vegetables,
or 3/4 cup vegetable juice; and
- fruit: 1 whole fruit, 1/2 cup of cut-up fruit,
or 3/4 cup fruit juice.
Note: current dietary guidance uses cups rather than servings.
Table 1. Median Portion Size (Pk)
in Grams per Mention by Age for Percentage Energy from Fat and Fiber
Analyses: Men
| Food Group |
Age Group |
| 18-27 |
28-37 |
38-47 |
48-57 |
58-67 |
68-77 |
78-99 |
| Men |
| Cold cereals
(P1) |
74.666667
|
61.500000
|
57.500000
|
56.000000
|
46.000000
|
39.000000
|
33.000000
|
| Whole milk
(P2) |
305.000000
|
259.250000
|
306.710000
|
244.000000
|
244.000000
|
244.000000
|
203.333333
|
| 2% milk (P3) |
259.250000
|
305.000000
|
244.000000
|
244.000000
|
244.000000
|
183.000000
|
183.000000
|
| 1% milk (P4) |
341.600000
|
245.000000
|
245.000000
|
244.000000
|
213.500000
|
223.666667
|
183.000000
|
| Skim milk
(P5) |
366.666667
|
250.000000
|
250.000000
|
245.000000
|
214.375000
|
198.937500
|
160.725000
|
| Other milk
(P6) |
163.340000
|
163.340000
|
163.340000
|
163.340000
|
163.340000
|
163.340000
|
163.340000
|
| Bacon or
sausage (P7) |
25.000000
|
40.250000
|
32.000000
|
32.000000
|
27.000000
|
26.000000
|
24.000000
|
| Hotdogs (P8) |
114.000000
|
85.500000
|
88.000000
|
114.000000
|
57.000000
|
57.000000
|
57.000000
|
| Whole grain
bread (P9) |
56.000000
|
54.000000
|
52.000000
|
52.000000
|
51.000000
|
48.250000
|
48.000000
|
| 100% fruit
juice (P10) |
372.000000
|
311.250000
|
249.000000
|
249.000000
|
248.000000
|
186.750000
|
186.750000
|
| Fruit (P11) |
131.750000
|
128.000000
|
123.200000
|
127.500000
|
122.000000
|
118.000000
|
114.250000
|
| Salad dressing
(P12) |
23.543333
|
23.626667
|
22.030000
|
27.500000
|
24.585000
|
19.285000
|
15.600000
|
| Fried potatoes
(P13) |
112.500000
|
114.000000
|
100.000000
|
100.000000
|
85.500000
|
85.500000
|
97.000000
|
| Other white
potatoes (P14) |
210.000000
|
196.000000
|
184.000000
|
161.000000
|
145.000000
|
127.000000
|
107.000000
|
| Dried beans
(P15) |
180.000000
|
130.000000
|
172.000000
|
172.000000
|
158.125000
|
175.000000
|
170.100000
|
| Other vegetables
(P16) |
60.013333
|
73.000000
|
74.063333
|
79.833333
|
76.500000
|
73.000000
|
67.520909
|
| Pasta (P17) |
330.000000
|
280.000000
|
280.000000
|
247.500000
|
280.000000
|
210.000000
|
210.00000
|
| Nuts (P18) |
31.625000
|
58.000000
|
35.500000
|
54.665000
|
39.250000
|
17.130000
|
35.916667
|
| Chips (P19) |
40.000000
|
40.000000
|
31.895000
|
30.000000
|
26.000000
|
21.000000
|
17.500000
|
Table 2. Median Portion Size (Pk)
in Grams per Mention by Age for Percentage Energy from Fat and Fiber
Analyses: Women
| Food Group |
Age Group |
| 18-27 |
28-37 |
38-47 |
48-57 |
58-67 |
68-77 |
78-99 |
| Women |
| Cold cereals
(P1) |
50.000000 |
49.500000 |
44.000000 |
43.500000 |
33.000000 |
33.000000 |
33.500000 |
| Whole milk
(P2) |
244.000000 |
244.000000 |
244.000000 |
244.000000 |
198.250000 |
198.250000 |
196.400000 |
| 2% milk
(P3) |
244.000000 |
244.000000 |
244.000000 |
244.000000 |
183.000000 |
183.000000 |
152.500000 |
| 1% milk
(P4) |
244.000000 |
244.000000 |
183.000000 |
152.500000 |
183.000000 |
183.000000 |
218.583333 |
| Skim milk
(P5) |
245.000000 |
245.000000 |
244.800000 |
229.690000 |
196.000000 |
183.750000 |
183.750000 |
| Other milk
(P6) |
61.000000 |
61.000000 |
61.000000 |
61.000000 |
61.000000 |
61.000000 |
61.000000 |
| Bacon or
sausage (P7) |
26.000000 |
25.000000 |
24.000000 |
24.000000 |
18.000000 |
19.500000 |
16.000000 |
| Hotdogs
(P8) |
57.000000 |
57.000000 |
57.000000 |
114.000000 |
57.000000 |
57.000000 |
57.000000 |
| Whole grain
bread (P9) |
50.000000 |
48.000000 |
47.500000 |
45.000000 |
45.000000 |
42.400000 |
34.000000 |
| 100% fruit
juice (P10) |
280.125000 |
249.000000 |
248.800000 |
233.250000 |
189.755000 |
186.600000 |
186.700000 |
| Fruit (P11) |
118.000000 |
118.000000 |
118.000000 |
118.000000 |
118.000000 |
112.427143 |
109.000000 |
| Salad dressing
(P12) |
17.140000 |
20.626667 |
23.020000 |
21.873333 |
22.035000 |
18.335000 |
10.210000 |
| Fried potatoes
(P13) |
79.500000 |
70.000000 |
70.000000 |
70.000000 |
66.000000 |
70.000000 |
64.000000 |
| Other white
potatoes (P14) |
122.000000 |
127.000000 |
116.000000 |
122.000000 |
105.000000 |
105.000000 |
105.000000 |
| Dried beans
(P15) |
126.500000 |
89.000000 |
126.500000 |
126.500000 |
126.500000 |
126.500000 |
173.000000 |
| Other vegetables
(P16) |
53.750000 |
61.625000 |
61.500000 |
61.532500 |
63.165000 |
67.142857 |
71.333333 |
| Pasta (P17) |
217.500000 |
217.500000 |
182.525000 |
185.000000 |
165.000000 |
160.000000 |
175.000000 |
| Nuts (P18) |
18.000000 |
32.000000 |
20.655000 |
21.265000 |
18.250000 |
11.250000 |
25.500000 |
| Chips (P19) |
28.000000 |
24.333333 |
27.000000 |
26.000000 |
20.000000 |
18.000000 |
14.000000 |
Table 3. Median Portion Size (Pk)
in Pyramid Servings* per Mention by Gender and Age for Fruits and Vegetables
Analyses
| Food Group |
Age Group |
| 18-27 |
28-37 |
38-47 |
48-57 |
58-67 |
68-77 |
78-99 |
| Men |
| 100% fruit
juice (P1) |
2.000000 |
1.667500 |
1.335000 |
1.335000 |
1.334000 |
1.001000 |
1.001000 |
| Fruit (P2) |
1.301000 |
1.301000 |
1.229571 |
1.227333 |
1.168000 |
1.168000 |
1.052333 |
| Salad (P3) |
0.545000 |
0.708000 |
0.754500 |
0.750000 |
0.833500 |
0.750000 |
0.822500 |
| Fried potatoes
(P4) |
2.000000 |
2.000000 |
1.773000 |
1.710000 |
1.400000 |
1.250000 |
1.250000 |
| Other white
potatoes (P5) |
2.000000 |
2.000000 |
1.999000 |
1.999000 |
1.914000 |
1.544000 |
1.508000 |
| Dried beans
(P6) |
1.374000 |
1.047000 |
1.065000 |
1.227000 |
1.000000 |
1.000000 |
1.114000 |
| Other vegetables
(P7) |
0.750000 |
0.906000 |
0.974500 |
1.000000 |
1.000000 |
0.880000 |
0.833333 |
| Women |
| 100% fruit
juice (P1) |
1.500500 |
1.334000 |
1.334000 |
1.251250 |
1.019500 |
1.000500 |
1.000500 |
| Fruit (P2) |
1.168000 |
1.168000 |
1.168000 |
1.168000 |
1.150500 |
1.083833 |
1.000000 |
| Salad (P3) |
0.613500 |
0.572500 |
0.833333 |
1.000000 |
0.795500 |
0.625000 |
0.750000 |
| Fried potatoes
(P4) |
1.481000 |
1.365500 |
1.272000 |
1.400000 |
1.000000 |
1.026000 |
1.000000 |
| Other white
potatoes (P5) |
1.544000 |
1.544000 |
1.528000 |
1.544000 |
1.499000 |
1.516000 |
1.272000 |
| Dried beans
(P6) |
0.964000 |
0.684000 |
0.800000 |
0.687000 |
0.822000 |
0.807000 |
1.000000 |
| Other vegetables
(P7) |
0.702200 |
0.779333 |
0.792500 |
0.788500 |
0.774000 |
0.833000 |
0.856750 |
* Defined by Dietary Guidelines Food Guide Pyramid (1992-2004).
- For percentage energy from fat and fiber (grams) estimation
of bk, k = 0, ..., 19: the values for
each parameter, for each gender, are in the following table:
Table 4. Estimated Regression
Coefficients for Foods as Predictors of Percentage Energy from Fat and
Grams of Fiber, by Gender
| Parameter |
Men |
Women |
| Percentage
Energy from Fat |
Fiber
(cube root) |
Percentage
Energy from Fat |
Fiber
(cube root) |
| Intercept (b0) |
31.952688 |
2.083624 |
31.371597 |
1.898219 |
| Cold cereals
(b1) |
-0.025863 |
0.002045 |
-0.057206 |
0.003843 |
| Whole milk (b2) |
0.006512 |
0.000129 |
0.008364 |
0.000095 |
| 2% milk (b3) |
0.002045 |
0.000137 |
0.002634 |
0.000115 |
| 1% milk (b4) |
-0.001500 |
0.000225 |
-0.002082 |
0.000245 |
| Skim milk (b5) |
-0.008536 |
0.000285 |
-0.008775 |
0.000344 |
| Other milk (b6) |
-0.026527 |
0.001474 |
-0.047247 |
0.003496 |
| Bacon or sausage
(b7) |
0.138079 |
-0.001377 |
0.231718 |
-0.002043 |
| Hotdogs (b8) |
0.041135 |
0 |
0.101657 |
-0.001416 |
| Whole grain bread
(b9) |
0 |
0.002827 |
0 |
0.003373 |
| 100% fruit juice
(b10) |
-0.005354 |
0.000187 |
-0.010099 |
0.000246 |
| Fruit (b11) |
-0.009290 |
0.001031 |
-0.011894 |
0.001046 |
| Salad dressing
(b12) |
0.149646 |
0 |
0.238928 |
0 |
| Fried potatoes
(b13) |
0.027202 |
0.001603 |
0.042656 |
0.001563 |
| Other white
potatoes (b14) |
0.005688 |
0.000716 |
0.006148 |
0.000658 |
| Dried beans
(b15) |
-0.005231 |
0.002748 |
-0.005934 |
0.003787 |
| Other vegetables
(b16) |
0 |
0.000839 |
0 |
0.000932 |
| Pasta (b17) |
-0.005029 |
0.000753 |
-0.005416 |
0.000826 |
| Nuts (b18) |
0.125658 |
0.005401 |
0.260003 |
0.006053 |
| Chips (b19) |
0.053905 |
0.005276 |
0.130953 |
0.004592 |
- For Pyramid servings of fruits and vegetables, estimation
of b0 and b1:
The model is: E(Dietary Factor1/2) = b0
+ b1 (NFG1P1
+ NFG2P2 + ...
+ NFG7P7)1/2
For Pyramid servings of fruits and vegetables, including and excluding
French fries, for each gender, the estimates of the parameters are:
Table 5. Estimated Regression Coefficients for Sum of Foods Predicting
Pyramid Servings of Total Fruits and Vegetables and Fruits and Vegetables
Excluding French Fries, by Gender
| Parameter |
Men |
Women |
| Summary variable with
French fries |
| Intercept (b0) |
0.906793 |
0.819559 |
| b1 |
0.758560 |
0.730865 |
| Summary variable excluding
French fries |
| Intercept (b0) |
0.940772 |
0.816265 |
| b1 |
0.739056 |
0.730219 |
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