PWM: Foods and Nutrients (2006)

Citation:
 
Study Design:
Class:
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Quality Rating:
Research Purpose:
  • To examine a number of anthropometric variables and the consumption of principal foods and nutrients among children aged 6-7 y, living in four Spanish cities with a substantial variation in IHD mortality.
Inclusion Criteria:

 Children ( age range, 6-7 y) in the four cities were selected through random cluster-sampling of schools, stratified, socio-economic level (ie, public schools) with no history of cardiovascular disease and nephrological disorders.

Exclusion Criteria:

Children reported by their parents to suffer from cardiovascular or nephrological diseases were excluded.

Description of Study Protocol:

 

This study examines a number of anthropometric variables and the consumption of principal foods and nutrients among children aged 6-7 y, living in four spanish cities (Cadiz , Murcia, Madrid and  Orense ) over the period 1998-1999 , with a substantial variation in IHD mortality. 

Children were selected through random cluster-sampling of schools, stratified by sex & socio-economic level. A total of 6 schools were selected in each city & in each school all 6-7 y old children were invited to take part.

Data were collected over a 6 week period on the physical measurements and administered a food frequency questionnaire to the children.   Statistical analysis was performed with the package (SAS /STAT, 1996).

The study protocol complied with Helsinki Declaration guidelines and Spanish legal provisions governing clinical research on humans (Real Decreto 561 Ethics Committee of the Fundacio. The study was orally presented to the Board of Governors (Consejo Escolar) of each of the schools. Following this, a letter was circulated to all parents, outlining the study goals and procedures, and asking for their written authorization.

In turn, parents were likewise requested to obtain the respective child consent.

Prevalence of overweight and obesity was calculated as the percentage of children exceeding BMI cut-off points. Information on food and nutrient intake was obtained through a food-frequency questionnaire.

The questionnaire included 77 food items, grouped in 11 sections .Frequency of consumption considered the following categories: times daily, weekly, monthly, annually and never.

 

Data Collection Summary:

Dependent:  Ponderal index (PI), BMI, Overweight (BMI > 17.6 kg/m2), Obesity (BMI > 20.1 kg/m2) BMI cut-offs based on international studies - heightt & weight measured following standardized procedures.

 

Independent:  Total energy, % of total energy from protein, total-carbohydrate, complex-carbohydrate, simple-carbohydrate energy, lipid energy, saturated-fat energy, monounsaturated fat energy, polyunsaturated fat energy, Protein (g/day), Carbohydrates (g/day): Complex, simple, Total lipids (g/day), Saturated fats, Monounsaturated Fats, Polyunsaturated fats, Oleic acid, Linoleic acid, cholesterol, total cholesterol, Fiber, Micronutrients (FFQ completed by children’s mothers)

Control Variables:  Birthweight, macr and micro nutrients

Statistical Analysis: 

Two types of analysis were performed. Statistical analysis was performed with the SAS package (SAS/STAT, 1996). Analysis are shown for the total number of children.

  • First, we ascertained the absolute differences in study variables for the high-IHD-mortality cities of Cadiz and Murcia and Orense, and then examined using non-paired tests. Subsequently, linear regression was used to adjust BMI and PI for birthweight, and discriminate whether the inter-city differences in these variables arise in the intrauterine period or after birth (Whincup logistic regression was used to adjust the prevalence of overweight and obesity for birthweight.
  • Second, the relationship of IHD mortality with anthropometric and dietary variables across the four cities was summarized with the Spearman correlation coef ficient.

 

Description of Actual Data Sample:

Original Sample:  6 schools in each city  and in each school with 50 per school ( 6x50=300; 300 children x4 cities=1200 children)

Withdrawals/Drop-Outs:  not specified.

Final Sample: Data obtained for 1112 children (557 boys and 555 girls).

Location:  4 Spanish cities (Cadiz,Murcia, Madrid and Orence)

Race/Ethnicity:  representative sample, spanish children.

Age:  6-7 years

Gender : Boys/Girls

Study Population : Children

Summary of Results:

 

Anthropometric measurements:

  •         The overall response rate was 85%, being similar for all four cities. The mean age of the children was 6.7 y, without substantial differences between cities. IHD mortality varied from a low of 77.05=100 000 in Orense to a high of 119.01=100000 in Cadiz .
  •       Variation in anthropometric variables across the four cities was as follows: BMI, 16.7 – 17.3 kg/m2; PI, 13.1 – 13.9 kg/m2; prevalence of overweight, 28.9 – 34.5%; and prevalenceof obesity, 8.5 – 15.7%. The city having the children with the lowest weight was Madrid and the city having the tallest children was Orense. Children in the two cities with high IHD mortality showed higher BMI, PI and prevalence of obesity than those in the two cities with low IHD mortality.
  •        There was a positive correlation (P<0.05) between these three anthropometric variables and IHD mortality across the four cities .
  •          After adjustment for birthweight, the above differences in anthropometric variables remained, although for obesity they were no longer statistically significant .

 

Demographic characteristics and anthropometric variables by city of residence; quantitative variables are shown as means and (standard error)
 

 
Cadiz
Murcia
Madrid
Orense
Difference (95% CL)
Spearman
correlation
coefficient
Ischaemic heart disease mortality
in 1993 – 1995 (per 105)
 
119.01
88.96
79.61
77.05
 
 
Number of children
250   
283
272
307
 
 
Sex (percentage males)
55.42
51.59
46.32
47.88
6.55(12.42; 0.68)*
-0.06*
Age (y)
6.83 (0.04)
6.71 (0.04)
6.55 (0.04)
6.77 (0.05)
0.11 (0.19; 0.03)*
0.04
Birthweight (kg)
3.35 (0.03)
3.38 (0.03)
3.21 (0.04)
3.30 (0.04)
0.11 (0.18; 0.04)**
0.05
Weight (kg)
27.23 (0.37)
26.93 (0.32)
25.70 (0.31)
27.00 (0.31)
0.73 (1.37; 0.09)
0.03
Height (cm)
124.89 (0.46)
124.68 (0.36)
124.59 (0.48)
126.92 (0.37)
-0.97 (-0.16; -1.78)**
-0.10**
Ponderal index (weight/height3; kg/m3)
13.90 (0.14)
13.81 (0.11)
13.43 (0.14)
13.12 (0.10)
0.58 (0.81; 0.35)**
0.68 (0.96;0.39)a**
0.16**

Body mass index (weight/

height2; kg/m2)
17.34 (0.17)  17.21 (0.15) 16.68 (0.16) 16.65 (0.13) 0.61 (0.91; 0.31)** 0.55 (0.91; 0.19)a 0.12**
Prevalance (percentage) of overweight (BMI>17.6 kg/m3)
34.50
32.86
28.86
27.87
5.32 (11.00; -0.37) 4.59 (11.98; -2.08)a
0.06
Prevalence (percentage) of obesity (BMI>20.1 kg/m2)
 
15.72
13.93
8.46
9.51
5.84 (9.81; 1.87)**
4.25 (10.92; -0.066)a
0.08**

Difference (95% CL): difference in study variables for Cadiz and Murcia minus Madrid and Orense (95% confidence limit).
Spearman correlation coefficient; correlation between each variable and ischaemic heart disease mortality across the four cities.
aDifferences adjusted for birthweight and sex.
*P <0.05; **P <0.01.

 

Dietary intake:

  • Compared with Madrid and Orense, the children of Cadiz and Murcia reported higher intakes of energy, protein (g/day), carbohydrates (g/day combine complex & simple), Simple carbohydrates (g/day), total lipids (g/day combine sat, monunsat, polyunsat, oleic acid, linoleic acid, cholesterol), saturated fats (g/day), polyunsaturated fats (g/day), linoleic acid (g/day) & cholesterol (mg/1000 cal/day).
  • No significant correlation noted when macronutrients examined at % of total energy. No sig. correlation noted with fiber (g/day).
  • Micronutrients, sodium intake was higher among children of the two

    high-cities. However, there were no substantial differences in intake of antioxidant vitamins, such as A and C, or folicacid vs the two low-IHD-mortality .

 

Nutrient intake, by city of residence; values are means and standard error

 
Cadiz
Murcia
Madrid
Orense
Difference (95% CL)
 
Spearman
correlation coefficient
 
Total energy (kcal=day)
2217.5 (36.0)
2151.4 (28.4)
2077.7 (28.5)
2082.5 (27.8)
104.35 (163.26; 45.44)**
0.09**
 
Protein energy (%)
17.0 (0.1)
17.2 (0.2)
17.3 (0.1)
17.3 (0.1)
70.20 (0.09; 70.49)
-0.05
Total-carbohydrate energy (%)
 
38.4 (0.3)
38.7 (0.3)
36.8 (0.3)
39.1 (0.4)
0.60 (1.28; 70.08)
0.00
Complex-carbohydrate energy (%)
 
17.5 (0.3)
18.1 (0.2)
17.6 (0.3)
18.0 (0.2)
0.00 (0.49; 70.49)
-0.03
Simple-carbohydrate energy (%)
 
21.4 (0.3)
21.5 (0.3)
20.0 (0.3)
21.9 (0.4)
0.50 (1.18; 70.18)
0.01
 Lipid energy (%) 
 46.2 (0.3)
 45.4 (0.2)
 47.3 (0.3)
 45.0 (0.3)
70.35 (0.16; 70.86)
0.05
 Saturated-fat energy (%)
 16.7 (0.2)
 16.7 (0.2)
 16.6 (0.2)
 16.9 (0.2)
70.05 (0.27; 70.37)
-0.04
 Monounsaturated-fat energy (%)
 17.7 (0.1)
 18.3 (0.1)
 18.7 (0.2)
 18.3 (0.2)
70.50 (70.20; 70.80)**
-0.10**
 Polyunsaturated-fat energy (%)
 8.2 (0.1)
 8.4 (0.1)
 8.7 (0.1)
7.9 (0.1)  
0.00 (0.21; 70.21)
0.07*
 Proteins (g=day)
 94.3 (1.7)
 92.7 (1.5)
 89.7 (1.4)
 90.2 (1.4)
3.55 (6.54; 0.55)
0.07*
 Carbohydrates (g=day)
 214.7 (4.5)
 209.4 (3.7)
 192.3 (3.5)
 204.0 (3.4)
13.90 (21.24; 6.56)**
0.07*
 Complex (g=day)
 98.9 (2.7)
 98.3 (2.2)
 92.3 (2.0)
 93.9 (1.8)
5.55 (9.77; 1.33)*
0.03
 Simple (g=day)
 118.7 (2.7)
 115.8 (2.5)
 104.5 (2.5)
 114.5 (2.6)
7.75 (12.82; 2.68)**
0.07*
 Total lipids (g=day)
 113.1 (1.7)
 108.0 (1.4)
 108.7 (1.5)
 104.1 (1.5)
4.15 (7.17; 1.13)**
0.12**
 Saturated fats (g=day)  40.6 (0.7)  39.6 (0.6)  38.1 (0.6)  38.9 (0.6)  1.60 (2.80; 0.40)*  0.08**
 Monounsaturated fats (g=day)  43.3 (0.7)  43.7 (0.7)  43.0 (0.6)  42.3 (0.7)  0.85 (2.17; 70.47)  0.05
 Polyunsaturated fats (g=day) 20.0 (0.4)  19.7 (0.3)    19.8 (0.3)  17.9 (0.3) 1.00 (1.59; 0.41)**    0.14**
 Oleic acid (g=day)  38.5 (0.6)  38.5 (0.6)  38.4 (0.6)  37.2 (0.6)  0.70 (1.90; 70.50)  0.06*
 
Linoleic acid (g=day)
 17.5 (0.3)  17.4 (0.3)  17.4 (0.2)  15.5 (0.3)  1.00 (1.56; 0.44)** 0.15** 
Cholesterol (mg=1000 cal=day)
172.5 (3.6) 182.9 (3.4) 161.7 (3.0) 161.7 (2.6) 16.00 (22.19; 9.81)** 0.11**
Total cholesterol (mg=day) 
373.7 (8.2) 393.9 (9.9) 329.7 (6.6) 331.2 (6.4) 53.35 (68.79; 37.91)** 0.17**
Fibre (g=day)
19.7 (0.5) 19.9 (0.4) 19.7 (0.4) 19.6 (0.4) 0.15 (1.02; 70.72) 0.00
 
Micronutrients
           
Calcium (mg=day)
1577.3 (34.2) 1457.8 (32.0)  1570.5 (34.2) 1686.3 (38.3) 7110.85 (741.76; 7179.94)** -0.08**
Sodium (mg=day) 3129.1 (66.6) 2690.4 (56.0) 2695.1 (59.6) 2482.7 (44.6) 320.85 (32.93; 208.77)** 0.22**
Potassium (mg=day) 3092.4 (67.0)  3250.0 (57.9) 3042.9 (49.5)  3102.0 (48.3) 98.75 (207.61; 710.11) -0.01
Vitamin C (mg=day) 211.5 (6.6) 190.1 (5.4) 192.0 (4.6) 199.4. (4.4) 5.10 (15.35; 75.15) 0.00
Vitamin B6 (mg=day) 1.1 (0.0) 1.1 (0.0) 1.1 (0.0) 1.0 (0.0) 0.05 (0.09; 0.01)* 0.07*
Vitamin A (mg=day)
696.3 (12.1) 642.5 (10.5) 662.6 (10.9) 658.5 (11.8) 8.85 (31.25; 713.55) 0.06*
 Vitamin D (mg=day)   5.0 (0.1)   4.7 (0.1)  6.0 (0.2)   5.0 (0.1)  70.65 (70.38; 70.92)** -0.12** 
 Vitamin E (mg=day)  10.9 (0.2)  11.5 (0.2)  11.5 (0.2)  10.0 (0.2)  0.45 (0.93; 70.03)*  0.12**
 Folic acid (mg=day)  211.0 (4.5)  208.2 (4.5)  210.0 (3.1)  201.9 (3.0)  3.65 (11.12; 73.82)  0.01

Difference (95% CL): difference in study variables for Cadiz and Murcia minus Madrid and Orense (95% confidence limit).
Spearman correlation coefficient: correlation between each variable and ischaemic heart disease mortality across the four cities.
*P <0.05; **P <0.01.

 

  • ·         Children of all four cities registered a high consumption of lipid- and protein-rich foods, such as meat, fish and dairy products, where whole milk predominates.
  • ·         Consumption of fruit and vegetables was likewise high.
  • ·         Cooking fats came mainly from olive oil. Intake of solid fats was relatively low, with margarine predominating over butter.
  • ·         Consumption of bakery products (pastries, buns, biscuits, etc), carbonated drinks and pre-cooked products was high .
  • ·         Egg consumption proved higher among the children of Cadiz and Murcia than among those of Madrid and Orense.
  • ·         Children in Orense consumed a smaller quantity of legumes, olive oil, carbonated drinks and pre-cooked products, and more sunflower oil than those living in the other three cities.
  • ·         No substantial inter-city differences were observed for the consumption of the other main groups of foods .

 

Food consumption, by city of residence. Values are means and (standard error); quantities expressed in g=day or cm3=day, for solids or liquids, respectively

 
Cadiz
Murcia
Madrid
 
Orense
Difference (95% CL)
Spearman
correlation coefficient
 
Diary products
 
636.2 (16.1)
641.3 (13.2)
614.9 (15.4)
619.1 (16.6)
21.75 (51.97; 78.47)
0.07*
Milk
 
326.5 (10.0)
364.1 (9.5)
404.2 (13.2)
411.7 (13.7)
762.65 (739.20; 786.10)**
-0.14**
Whole milk
 
279.2 (11.2)
241.4 (12.3)
333.1 (13.8)
344.2 (15.2)
778.35 (751.97;7104.3)**
-0.11**
Part-skim milk
47.3 (7.4)
122.7 (11.4)
71.1 (11.8)
77.5 (11.0)
10.70 (31.96; 710.56)
0.03
Cheese
 
16.1 (1.1)
24.9 (1.7)
16.1 (0.9)
16.6 (1.1)
4.15 (6.66; 1.64)**
0.04
Youghurt
 
166.9 (7.2)
146.8 (6.6)
117.0 (5.6)
151.4 (6.3)
22.65 (35.34; 9.96)**
0.07*
Eggs
19.0 (0.6)
20.1 (0.7)
17.1 (0.7)
16.8 (0.5)
2.60 (3.80; 1.40)**
0.14**
Meat products
 
93.2 (2.6)
98.3 (2.2)
103.4 (3.0)
89.3 (1.7)
70.60 (4.10; 75.30)
0.02
Poultry
25.0 (0.9)
29.4 (0.8)
26.6 (0.7)
18.7 (0.6)
4.55 (6.10; 3.00)**
0.22**
Other
27.5 (1.2)
26.6 (0.9)
42.7 (2.5)
37.2 (1.0)
712.90 (79.93; 715.86)**
-0.29**
Sausage meats
 
38.8 (1.6)
40.9 (1.5)
33.0 (1.2)
32.2 (1.0)
7.25 (9.83; 4.67)**
0.13**
Fish
 
48.6 (2.3)
41.1 (2.9)
45.6 (1.2)
39.6 (1.2)
2.25 (6.19; 71.69)
0.04
White
 
30.2 (1.7)
24.1 (2.7)
29.8 (0.9)
19.7 (0.7)
2.40 (5.74; 70.94)
0.13**
Blue
 
13.1 (0.9)
12.8 (0.7)
12.0 (0.6)
14.7 (0.8)
70.40 (1.08; 71.88)
-0.08*
Fruit and vegetables
 
640.7 (21.3)
665.8 (18.1)
678.2 (19.6)
603.9 (16.9)
12.20 (49.36; 724.96)
0.03
Fruit
 
345.5 (13.0)
283.8 (9.8)
342.3 (12.9)
308.5 (12.7)
710.75 (13.24; 734.74)
0.04
Greens and other vegetables
 
295.2 (14.3)
382.0 (13.0)
335.9 (13.3)
295.4 (10.2)
22.95 (47.98; 72.08)*
0.01
Greens
 
91.4 (6.3)
146.0 (7.7)
123.5 (6.2)
91.8 (5.0)
11.05 (23.73; 71.63)*
0.01
Other vegetables
 
12.7 (1.9)
13.0 (1.5)
13.1 (1.5)
13.5 (1.3)
70.45 (2.58; 73.48)
-0.07*
Potatoes
 
100.0 (6.0)
92.8 (3.0)
97.0 (4.5)
108.9 (4.9)
76.55 (2.59; 715.69)
-0.08**
Legumes
 
20.2 (1.2)
22.0 (2.9)
19.6 (0.9)
10.8 (0.4)
5.90 (9.12; 2.68)**
0.28**
 Breakfast cereals
 12.5 (1.0)
 12.4 (1.0)
 13.0 (0.8)
 15.0 (1.1)
 71.55 (0.43; 3.53)
 -0.04
 Oils and fats
 36.1 (0.7)
 32.3 (0.4)
 31.8 (0.3)
 30.9 (0.3)
 2.85 (3.71; 1.99)**
 0.30**
 Olive oil
 23.3 (0.6)
 21.7 (0.5)
 23.2 (0.5)
 16.0 (0.6)
 2.90 (4.04; 1.76)**
 0.24**
 Sunflower oil
 8.3 (0.5)
 6.1 (0.5)
 4.5 (0.4)
 11.4 (0.6)
 70.75 (0.36; 71.86)**
 -0.23**
 Butter
 3.9 (0.5)
 1.3 (0.2)
 0.9 (0.1)
 0.9 (0.2)
 1.70 (2.28; 1.13)**
 0.23**
 Margarine
 4.4 (0.5)
 3.0 (0.4)
 2.9 (0.3)
 2.0 (0.2)
 1.25 (1.91; 0.59)**
 0.15**
 Bakery products
 83.77 (3.92)
 95.54 (4.10)
 87.56 (3.75)
 81.83 (3.56)
 6.46 (13.99; 71.07)
 0.06
Bottled=canned beverages 322.8 (16.6) 198.3 (8.8) 242.9 (12.8) 177.5 (8.1) 50.35 (73.84; 26.86)** 0.23**
Carbonated drinks 87.6 (8.7) 29.9 (2.9) 37.5 (3.4) 35.2 (3.9) 22.40 (32.43; 12.37)** 0.18**
Non-carbonated drinks 11.4 (3.2) 4.6 (1.0) 9.8 (1.8) 6.6 (2.1) 70.20 (3.90; 74.30) 0.04
Non-natural juices 119.4 (7.4) 77.2 (6.5) 90.9 (9.1) 34.2 (4.1) 35.75 (49.52; 21.98)** 0.33**
Natural juices 102.9 (8.2) 80.9 (5.3) 98.7 (7.8) 97.3 (5.1) 76.10 (6.83; 719.03) -0.02
Pre-cooked foods 48.8 (3.0) 31.3 (2.0) 26.1 (2.0) 24.1 (2.0) 14.95 (19.41; 10.49)** 0.27**
Salt added to meals 2.0 (0.2) 2.8 (0.2) 1.6 (0.01) 1.4 (0.1) 0.90 (1.22; 0.58)** 0.11**

 
Difference (95% CL): difference in study variables for Cadiz and Murcia minus Madrid and Orense (95% confidence limit).
Spearman correlation coefficient: correlation between each variable and ischaemic heart disease morality across the four cities.
·         *P <0.05; **P <0.01.

 

Author Conclusion:
  • Intake of fats, especially saturated fats, and cholesterol should be reduced among Spanish children.
  • It could contribute to a needed reduction of the high prevalence of overweight and obesity in children.
  • If the differences in anthropometric variables and diet between children from the cities with high and low coronary mortality are maintained in future or continue into adulthood, this could contribute to consolidate or even increase the IHD mortality gradient across cities.
  • The finding that differences in anthropometric variables are independent of birth weight suggests that the childhood, rather than intrauterine environment, is involved in the development of such differences.
  • They show an urgent need to improve the diet of Spanish children.
  • Consumption of cereals should be increased and that of sausage meats, simple sugars and precooked foods decreased.
  • If the differences in anthropometric variables and diet among children from cities with different coronary mortality, this could contribute to consolidate or even increase the CHD mortality gradient between the cities.
  • The finding that differences in anthropometric variables are independent of birthweight suggests that the childhood, rather than intra-uterine environment, is involved in the development of such differences.
  • The contribution of diet, physical activity and other factors to the emergence of differences in overweight and obesity among children should be studied in the future.
Funding Source:
Government: Comunidad Autonoma de Madrid
Industry:
International Olive Oil Board (Consejo OleiĀ“cola Internacional)
Commodity Group:
Not-for-profit
0
Foundation associated with industry:
Reviewer Comments:
  •  It is a  cross sectional survey  undertaken in Spain on food & nutrition among school children.
  • Inclusion  and exclusion criteria is not very clear.
  • It is a study conducted in only 4 provinces. It is not very clear whether the sample is overall a representative sample of the children. 
  • The author agreed that  the diet measurement errors that tend to be present in studies on children. 
  • This study is related to cardiovascular mortality and the study examined only dietary factors and BMI. It is necessary to see the correlation of their lipid profile and inflammatory makers associated with anthropometric measurements and dietary factors.
  • Family history of the children is very important for this study.  It is a study conducted between 1998-1999. It is not clear whether there is any follow up of the survey.
  • Children were selected through random cluster-sampling of schools, stratified by sex & socio-economic level but there is no data related to their socio-economic level and no correlation was reported with diet and anthropometric data.
  • The dietary patterns were also not correlated with anthropometric measurements and dietary factors.
  • Further studies are required to study the correlation of traditional and non traditional CHD risk factors with diet and physical activity of children.

 

 

 

Quality Criteria Checklist: Primary Research
Relevance Questions
  1. Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies) N/A
  2. Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about? Yes
  3. Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice? Yes
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) Yes
 
Validity Questions
1. Was the research question clearly stated? Yes
  1.1. Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified? Yes
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? Yes
  1.3. Were the target population and setting specified? Yes
2. Was the selection of study subjects/patients free from bias? ???
  2.1. Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study? ???
  2.2. Were criteria applied equally to all study groups? ???
  2.3. Were health, demographics, and other characteristics of subjects described? Yes
  2.4. Were the subjects/patients a representative sample of the relevant population? ???
3. Were study groups comparable? ???
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) N/A
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? N/A
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) N/A
  3.4. If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis? N/A
  3.5. If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.) N/A
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? N/A
4. Was method of handling withdrawals described? No
  4.1. Were follow-up methods described and the same for all groups? No
  4.2. Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.) No
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? ???
  4.4. Were reasons for withdrawals similar across groups? N/A
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? N/A
5. Was blinding used to prevent introduction of bias? N/A
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? N/A
  5.2. Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.) N/A
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? N/A
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? N/A
  5.5. In diagnostic study, were test results blinded to patient history and other test results? N/A
6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described? N/A
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? N/A
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? N/A
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? N/A
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? N/A
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? N/A
  6.6. Were extra or unplanned treatments described? N/A
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? N/A
  6.8. In diagnostic study, were details of test administration and replication sufficient? N/A
7. Were outcomes clearly defined and the measurements valid and reliable? N/A
  7.1. Were primary and secondary endpoints described and relevant to the question? N/A
  7.2. Were nutrition measures appropriate to question and outcomes of concern? N/A
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? N/A
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? N/A
  7.5. Was the measurement of effect at an appropriate level of precision? N/A
  7.6. Were other factors accounted for (measured) that could affect outcomes? N/A
  7.7. Were the measurements conducted consistently across groups? N/A
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? N/A
  8.1. Were statistical analyses adequately described and the results reported appropriately? N/A
  8.2. Were correct statistical tests used and assumptions of test not violated? N/A
  8.3. Were statistics reported with levels of significance and/or confidence intervals? N/A
  8.4. Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)? N/A
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? N/A
  8.6. Was clinical significance as well as statistical significance reported? N/A
  8.7. If negative findings, was a power calculation reported to address type 2 error? N/A
9. Are conclusions supported by results with biases and limitations taken into consideration? N/A
  9.1. Is there a discussion of findings? N/A
  9.2. Are biases and study limitations identified and discussed? N/A
10. Is bias due to study's funding or sponsorship unlikely? N/A
  10.1. Were sources of funding and investigators' affiliations described? N/A
  10.2. Was the study free from apparent conflict of interest? N/A