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Table 1 Baseline characteristics according to a 14-point dietary adherence score after 1, 4 years of follow-upa

From: Predictors of short- and long-term adherence with a Mediterranean-type diet intervention: the PREDIMED randomized trial

 

1 Year of Follow-up

 

4 Years of Follow-up

 

Adherenceb

Low (n = 1925)

High (n = 2273)

 

Low (n = 978)

High (n = 1375)

 

Demographic Characteristics c

% or mean (SD)

p-value

% or mean (SD)

p-value

Women

59.1

54.6

0.003

61.3

54.6

0.001

Age at Baseline (years)

66.9 (6.1)

66.9 (5.9)

0.68

67.6 (6.2)

66.8 (5.8)

0.005

Educational level

      

 University

7.5

8.8

 

5.6

8.7

 

 Secondary school

14.8

16.2

 

15.8

15.0

 

 Primary school

74.7

72.8

 

75.0

74.8

 

 Less than primary school

3.1

2.2

0.06

3.6

1.6

0.001

Occupation

      

 Retired

51.6

54.6

 

50.9

53.0

 

 Working

13.1

11.3

 

10.4

11.4

 

 Housewife

31.5

31.6

 

35.7

33.0

 

 Unemployed/unable to work

3.8

2.6

0.02

3.0

2.7

0.51

Marital Status

      

 Married

75.9

78.9

 

75.6

78.9

 

 Single

3.7

3.7

 

3.5

3.9

 

 Widowed

18.6

15.1

 

19.1

15.4

 

 Divorced or separated

1.8

2.2

0.22

1.8

1.8

0.12

Number of People in Household

1.7 (1.3)

1.7 (1.4)

0.89

1.6 (1.1)

1.6 (1.5)

0.87

Health-Related Characteristics at Baseline

      

Number of CVD Risk Factorsc

      

 0-1

5.8

7.6

 

6.7

10.1

 

 2

27.1

31.5

 

28.6

33.0

 

 3

39.1

38.7

 

37.5

37.6

 

 4

21.9

17.7

 

21.2

16.2

 

 5-6

6.1

4.5

<0.001

6.0

3.1

<0.001

Type 2 diabetes

51.5

44.3

<0.001

53.1

44.6

<0.001

Hypertension

82.2

81.

0.60

82.2

80.2

0.21

Hypercholesterolemia

70.8

73.3

0.06

66.5

69.5

0.12

Family history of premature CHD

24.1

21.9

0.10

24.7

17.5

<0.001

Depression

18.1

16.2

0.10

17.9

14.8

0.04

Obesity

49.0

42.8

<0.001

47.4

42.7

0.02

SBP (mmHg)

148.5 (20.7)

149.7 (20.6)

0.07

148.5 (20.6)

150.5 (20.9)

0.02

DBP (mmHg)

82.9 (10.8)

83.5 (11.1)

0.09

83.3 (11.2)

84.1 (10.9)

0.10

Waist circumference (cm)

101.2 (10.0)

99.1 (10.6)

0.004

100.8 (10.3)

98.7 (10.0)

<0.001

Physical activity (MET-min/d)d

      

 T1 (low)

36.1

27.7

 

36.7

24.7

 

 T2

34.3

33.6

 

34.0

33.5

 

 T3 (high)

29.6

38.6

<0.001

29.4

41.8

<0.001

Smoking status

      

 Never

62.1

60.7

 

65.0

61.5

 

 Former

14.7

12.9

 

12.9

14.1

 

 Current

23.2

26.4

<0.03

22.1

24.4

0.22

Total energy intake (kcal/day)e

      

 Q1 (low)

27.3

21.4

 

24.6

19.9

 

 Q2

24.5

25.1

 

24.2

22.9

 

 Q3

25.3

26.5

 

23.7

27.0

 

 Q4 (high)

23.0

27.1

<0.001

27.6

30.3

0.02

Alcohol other than wine (g/day)

      

  < 10 men, <5 women

57.9

57.6

 

58.6

57.0

 

 10-50 men, 5–10 women

14.2

14.7

 

14.7

14.7

 

  > 50 men, > 10 women

27.9

27.7

0.90

26.7

28.3

0.68

14-point adherence scoreb

8.2 (1.8)

9.3 (1.8)

<0.001

8.5 (2.0)

9.3 (1.9)

<0.001

Intervention Design Features

      

Intervention Group

      

MedDiet + EVOO

58.0

49.2

 

60.7

53.2

 

MedDiet + Nuts

42.0

50.8

<0.001

39.3

46.8

<0.001

Total workload of center (person-years) f

      

 Q1 (low)

34.4

26.7

 

25.4

23.3

 

 Q2

27.3

26.8

 

41.3

33.0

 

 Q3

22.7

32.2

 

19.9

12.2

 

 Q4 (high)

15.6

15.4

<0.001

13.4

31.5

<0.001

  1. a Those randomized after November 2006 did not have the opportunity to provide information on 4-year adherence. b A validated MedDiet adherence assessment tool was used. 1 point was added for each item in adherence with the traditional MedDiet. High adherence = adherence with ≥11 items on 14-point dietary adherence score. Low adherence = adherence with <11 items. c Total CVD risk score was calculated by summing the following CVD risk factors: type 2 diabetes, hypertension, high blood cholesterol, family history of premature CHD, depression, obesity. d Tertiles of physical activity (MET-min/d): T1: <108; T2: 108–268; T3: ≥268. e Quartiles of energy intake (kcal/d), by sex: Men: Q1: <2051; Q2: 2051- < 2394; Q3:2934- < 2801; Q4: ≥2801. Women: Q1: <1786; Q2: 1786- < 2109; Q3: 2109- < 2465; Q4: ≥2465. f Measured in quartiles of person years at center. After 1 Year: Q1: 133- < 352; Q2: 352- < 537; Q3: 537- < 650; Q4: ≥650. After 4 years: Q1: 893- < 1220; Q2: 1220- < 2175; Q3: 2175- < 2384; Q4: ≥2384