Study (Year) | Country | Study design | Selection of participants | Number of practices | Participants randomised (% Female) | Eligible age range (mean) years | Ethnicity and socioeconomic status | Diet assessment tool |
---|---|---|---|---|---|---|---|---|
Baron (1990) [33] | UK | RCT | Randomly selected participants registered with a family practice | One group general practice | 437 randomised 368 participated (49) | 25-60 (41.7) | Social class 1 or 2: controls, 30% men, 24% women; intervention 39% men, 43% women. | Self-administered food frequency questionnaire |
Beresford (1997) [35] | USA | Cluster RCT | Participants attending routine visits without major illness | 28 physician practices within 6 clinics | 2121 (68) | 26% > 65 years | White: 91%; Some college education: 73%. Family income below $25000 per year: 28%. | Telephone interview administered food frequency questionnaire |
Coates (1999) [28] | USA | RCT | Post menopausal women volunteers, consuming at least 36% energy from fat | University clinical centres in three states | 2208 (100) | 50-79 (60) | White (55%), Black (28%), Hispanic (16%); <High School (11%), High School (20%), Post high school with no college degree (35%), graduate /post graduate (33%) | Self-administered food frequency questionnaire |
Fries (2005) [34] | USA | RCT | Randomly selected participants from physicians’ lists | Three rural Virginia physician practices | 754 (64) | 18-72 (46.34) | White: 61%, African American: 37%; 8th grade: College degree: 24%; Income < $10,000: 14.69%, ≥$41,000:19%. | Telephone interview administered fat and fibre behaviour questionnaire |
Gann (2003) [36] | USA | RCT | Women volunteers aged 20–40 years recruited through advertising and direct mail in Chicago. | One clinic | 213 (100) | 20-40 (33.4) | 76% White, 13.5% Black, 4% Hispanic, 5.5% Asian, 1.5% other; 85% completed college | Telephone interview administered food frequency questionnaire, based on 24 hr diet recall on each of three days |
Kristal (2000) [32] | USA | RCT | Randomly selected patients enrolled with an HMO. | Health maintenance organisation | 1459 (50) | 18-69 (45.8) | White (85.9%), Black (4.5%), Asian (5.8%), Hispanic (3.0%), Other (0.8%); Household income < $25,000 12.2%, ≥$70,000 21.7%. | Telephone interview administered Food Frequency Questionnaire (FFQ) and Diet Habits Questionnaire |
Roderick (1997) [29] | UK | Cluster RCT | Unselected patients attending GP surgery practices | 8 family practices | 956 (50) | 35-59 (47.3) | Non-manual occupation, intervention 60%, control 49%; rented accommodation intervention 11%, control 25%. | Self-administered food frequency questionnaire. |
Sacerdote (2006) [30] | Italy | RCT | Unselected patients, not obese, no chronic disease | 33 general practitioners | 3179 (50) | 18-65 (44.5) | Not reported | Family physician administered food frequency questionnaire |
Stevens (2003) [31] | USA | RCT | Women with recent negative mammogram and total cholesterol ≥200 mg/dl | Health maintenance organization (HMO) | 616 (100) | 40-70 (53.8) | Minority groups: 7%; College graduates: 40% | Self-administered fat and fibre behaviour questionnaire (FFBQ) |
Takahashi (2006) [27] | Japan | RCT | Healthy volunteers in two rural villages, advice given after annual health checks | Not reported | 550 (68) | 40-69 (56) | Not reported | Self-administered diet history questionnaire (DHQ) |