Hong Kong has adopted Hong Kong Financial Reporting Standards (HKFRS) from 2005 whereas mainland has adopted New CAS from 2008, which are both considered equivalent to IFRS, an indication of higher reporting quality.
Studies of higher reporting quality minimise bias [ 21].
All three trials were of the highest reporting quality, and had high validity scores, indicating that known sources of bias are unlikely to occur [ 22, 8].
13 While these studies generally show that endorsement is associated with higher reporting quality, they also show that journal instructions sometimes cite outdated versions of guidelines and also clearly demonstrate that endorsement alone is insufficient to ensure adherence.
Our view was that including open studies would have required additional sensitivity analysis, and that with 43,000 patients treated with statins and 25,000 treated with placebo there was a sufficiency of data from studies of higher reporting quality.
The five included studies were of generally high reporting quality (quality scores of 4 or 5), known to be associated with minimal reporting bias [ 30, 31].
Papers were of good to high reporting quality, with one scoring 2, 13 scoring 3, nine 4, and four 5, out of a maximum 5 points.
Moreover, Poolman et al. [ 50] suggested that readers should not assume that studies labelled as Level I are of a high reporting quality, or of a better reporting quality than Level II studies.
Our findings suggest that readers should not assume that 1) studies labelled as Level I have high reporting quality and 2) Level I studies have better reporting quality than Level II studies.
The 37 included studies were of generally high reporting quality (quality scores between 2 and 5, median 4 [ 10]), known to be associated with minimal reporting bias [ 11, 12].
