Table 3

Quality assessment of trials included in the meta-analysis

Trial ID

Total score

Blinding

Outcome measure: blood pressure

Loss to follow-up

Funding source

Compliance; other chocolate diary

Scores given

1: choc + control blinded

1: Primary

1: < 20%

1: Sponsor not involved in data collection, analysis

1: Compl assessed; no sign diff between groups

0.5: control blinded

0.5: Secondary

0: ≥ 20%

0: Sponsor involved

1: Compl assessed, sign diff included in analysis

0: No blinding

0: Compl not assessed

Taubert et al. [10]

4

0: dark/white

1

1: none

1

1

Murphy et al. [15]

3.5

1: cocoa tablets

0.5

1: 9.5% (4 of 42)

0: supported by Mars

1: tablet count, 7 day weight food records x2

Engler et al. [11]

5

1: flav bar matched

1

1: none

1

1

Fraga et al. [12]

2.5

0: dark/white

1

1: 3.6% (1 of 28)

0: 3 authors from Mars

0.5: reported what consumed, no diary

Grassi et al. [13]

3.5

0: dark/white

1

1: none

0.5: unclear

1: daily diary

Grassi et al. [13]

3.5

0: dark/white

1

1: none

0.5: unclear

1: daily diary

Taubert et al. [16]

4

0: dark/white

1

1: none

1

1: food diary

Crews et al. [17]

2.5

0.5: flav drink; > 50% assumed correct group they were in

1

0.5: 11% (11 of 101)

0.5: independent industry research grant, supplier

0: not reported

Grassi et al. [18]

3.5

0: dark/white

1

1: none

0.5: unclear

1: diary

Muniyappa et al. [20]

3

1: flav drink; blinding assessed ok

1

0: 31% (9 of 29)

1

0: not reported

Davison et al. [21]

3

1: flav drink

1

0: 21% (14 of 65)

0: Mars Financial support

1: diet + background exercise

Davison et al. [21]

3

1: flav drink

1

0: 21% (14 of 65)

0: Mars Financial support

1: diet + background exercise

Shiina et al. [22]

2

0: dark/white

0

1: none

1

0

Ried et al. [23]

4.5

0.5: control blinded

1

1: 8% (3 of 39)

1

1: diary

Monagas et al. [24]

3.5

0: cocoa powder in milk/milk

0.5

1: none

1

1: diet monitoring (3-day food questionnaires x3)

All 15 trial arms were adequately randomised.

Choc, chocolate; compl, compliance; flav, flavanol; sign diff, significant difference;

Ried et al. BMC Medicine 2010 8:39   doi:10.1186/1741-7015-8-39