Table 2 Comparisons of percent 'yes' and percent 'differences' using the Quality of Reporting of Meta-analyses (QUOROM).

1

Title

Identified the report as a meta-analysis [or systematic review] of randomized trials.

0, 0%

0, 0%

0% NS

2

Abstract

Used a structured format.

100%

100%

0% NS

3

Objectives

The clinical question explicitly.

96.2% [91.0 to 100.0]

98% [94.4 to 100.0]

1.9% [-1.8 to 7.0] 0.56

4

Data sources

The databases (e.g. list) and other information sources.

76% [63.8 to 87.2]

93% [85.3 to 99.6]

17.0% [9.8 to 28.7] 0.01

5

Review methods

The selection criteria (e.g. population, intervention, outcome, and study design; methods for validity assessment, data abstraction, and study characteristics, and quantitative data synthesis) in sufficient detail to permit replication.

40% [26.3 to 52.9]

76% [63.8 to 87.2]

35.9% [24.1 to 49.1] 0.00

6

Results

Characteristics of the randomized trials included and excluded; qualitative and quantitative findings (e.g. point estimates and confidence intervals); and subgroup analyses.

71% [59.5 to 83.9]

77% [66.0 to 88.7]

5.7% [-5.7 to 17.9] 0.50

7

Conclusion

The main results.

96% [91.4 to 100.0]

98% [94.4 to 100.0]

1.9% [-1.8 to 7.1] 0.56

8

Intro

The explicit clinical problem, biologic rationale for the intervention, and rationale for review.

98% [94.4 to 100.0]

100%

2% [1.9 to 5.6] 0.31

9

Methods

Searching

The information sources, in detail (e.g., databases, registers, personal files, expert informants, agencies, hand-searching], and any restrictions (e.g. years considered, publication status, language of publication).

68% [55.2 to 80.6]

87% [77.7 to 96.0]

18.9% [9.7 to 31.6] 0.02

10

Selection

The inclusion and exclusion criteria (defining population, intervention principal outcomes, and study design).

100%

96% [91.0 to 100.0]

-3.7% [-9.0 to 3.8] 0.15

11

Validity assessment

The criteria and process used [e.g., masked conditions, quality assessment and their findings.

87% [77.6 to 96.0]

96% [91.0 to 100.0]

9.4% [4.3 to 18.6] 0.08

12

Data abstraction

The process used (e.g., completed independently, in duplicate).

74% [61.6 to 85.6]

93% [85.3 to 99.6]

18.9% [11.7 to 30.9] 0.01

13

Study characteristics

The type of study design, participants' characteristics, details of intervention, outcome definitions, etc.; and how clinical heterogeneity was assessed.

89% [61.6 to 85.6]

96% [91.0 to 100.0]

7.6% [2.4 to 16.1] 0.14

14

Quantitative data synthesis

The principal measures of effect [e.g., relative risk], method of combining results (statistical testing and confidence intervals), handling of missing data, etc.; how statistical heterogeneity was assessed; a rationale for any a priori sensitivity and subgroup analyses; and any assessment of publication bias.

83% [72.8 to 93.2]

79% [68.2 to 90.2]

-3.7% [-14.8 to 6.4] 0.62

15

Results

Trial flow

Provide a meta-analysis profile summarizing trial flow

2% [-1.8 to 5.6]

8% [0.36 to 14.7]

5.7% [-1.5 to 9.4] 0.17

16

Study characteristics

Present descriptive data for each trial [e.g., age, sample size, intervention, dose, and duration, follow-up].

89% [80.1 to 97.3]

83% [72.9 to 93.2]

-5.7% [-15.9 to 2.9] 0.40

17

Quantitative data synthesis

Report agreement on the selection and validity assessment; present simple summary results [for each treatment group in each trial, for each primary outcome]; data needed to calculate effect sizes and confidence intervals in intention-to-treat analyses [e.g., 2 × 2 tables of counts, means and standard deviations, proportions].

81% [70.5 to 91.8]

89% [80.1 to 97.3]

7.5 [-1.1 to 18.2] 0.28

18

Discussion

Summarize the key findings; discuss clinical inferences based on internal and external validity; interpret the results in light of the totality of available evidence; describe potential biases in the review process [e.g., publication bias]; and suggest a future research agenda.

96% [91.0 to 100.0]

96% [91.0 to 100.0]

0% [-5.2 to 5.2] NS