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. 2013 May;16(5):361–374. doi: 10.1089/jmf.2012.2682

Table 2.

Quality Assessment of Included Studies

Study ID Descriptiona Loss to follow-up Compliance Dietary advice
Collins et al.27 Randomized (blinding not described) n.a. Compliance by measuring plasma lycopene Four weeks of vitamin E supplement before initiation
Carroll et al.28 Randomized, double blinded 11/58
18.9%
Compliance by questioning volunteers, counting returned capsules monthly, and measuring plasma response n.a.
Hininger et al.29 Randomized, single blinded n.a. n.a. n.a.
Kucuk et al.30 Randomized (blinding not described) n.a. Compliance was assessed by performing remaining pill counts at the end of the intervention Instructed to increase daily fruit and vegetable intake to five servings for control group
Briviba et al.31 Randomized, double blinded 0 No participant excluded for health problems, compliance, or other reasons Instructed to refrain from carrot and tomato product 4 weeks before and during treatment
Riso et al.32 Randomized, double blinded n.a. Compliance by weekly interviews, frequency of consumption of fruits and vegetables Instructed to maintain habitual diet
Zhao et al.33 Randomized, double blinded n.a. Compliance by counting pills, checking food calendar, 3-day food records, and food-frequency questionnaires biweekly Instructed to exclude foods rich in carotenoids and to limit fruit and vegetable intake to two servings/day of light-colored fruit and vegetables for 2 weeks before and during treatment
Neyestani et al.34 Randomized, double blinded n.a. Dietary assessment was carried out after washout and after intervention Instructed to follow a lycopene-free diet for a 2-week washout period and instructed to keep their diets and physical activities constant during the experimental period
Devaraj et al.35 Randomized, double blinded 5/82
6.10%
Compliance (93.9%) by food diary, tablet counting, and plasma lycopene measurement Instructed to refrain from lycopene-containing food for 2 weeks before and during treatment
Talvas et al.36 Randomized, single blinded 0 Compliance by an interview with dietitian Instructed to avoid sources of tomato/lycopene 2 weeks before and during treatment
Mackinnon et al.26 Randomized (blinding not described) 5/65
7.69%
Compliance by using supplement counting Instructed to refrain from lycopene-containing food 1 month before and during treatment and from vitamins containing antioxidants and nutritional supplements during the study
Kim et al.37 Randomized, double blinded 10/126 7.94% Compliance (92.1%) at the end of the study using pill counting, food records, and measurement of plasma lycopene levels Instructed to maintain usual lifestyle and dietary habits
van Breemen et al.38 Computer-generated pseudorandom number for randomization; the method of double blinding was described and it was appropriate.
Allocation of concealment: subjects enrolled by the study manager
26/131
19.85%
Compliance (99%) by calendars to record capsules and capsule counting, reminded to take capsules during calls for 24-hour dietary recalls Dietary intakes of lycopene and other carotenoids and nutrients at baseline and during the study were determined on the basis of five 24-hour dietary recalls
a

Randomization and blinding, as described by the literature. Allocation of concealment was not described for any of the studies except for van Breemen et al.38

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