During the second selection step, full texts of the papers were read to check whether the first selection step was done correctly, and to exclude studies based on the following criteria: missing data on FMD, no measures of variability of FMD reported, no suitable control treatment included in the design, and no full text available.
There was no good text available.
Articles were excluded if not reporting original data, such as reviews, letters, and conference abstracts (no full text available).
We conducted the search using keywords for the patient population and outcome, see Table 1.> We used the following exclusion criteria: articles not in English, Dutch or German, case reports or no full text available.
Other filters included 'review' for the category of article type and 'full text available' and 'free full text available' for the category of text availability.
94.8% of these citations were written in English, 55.2% had an abstract available, 93.2% had the full text available (either for a fee or at no charge) and 35.6% had the full text available at no charge.
By using the 'abstract available', the 'full text' and the 'free full text' filters we determined that 32.9% of publications had the abstract available, 94.1% had the full text available (either for a fee or at no charge) and 25.7% had the full text available at no charge.
By repeating the same searches with publications with an abstract available, we observed that 96.2% of the articles were written in English, 100% (as obvious) had an abstract available, 93.5% had the full text available (either for a fee or at no charge) and 42.7% had the full text available at no charge.
Full text available upon request.
Full text available from the authors.
Keyword searchable with full text available in text format, does not include advertisements or photos.
