Risk of bias in studies
MINORS scores are presented in table 1. The median MINORS score was 9
(range 6-13) out of a maximal score of 16. In general studies presented
clearly stated aims, however lack of clarity on whether consecutive
patients were included was a frequent issue. Endpoints were typically
well defined, and reporting was unbiased. None of the studies
prospectively calculated a study size and there was variable reporting
on minimal follow-up periods and attrition rates, thus impacting
reliability of extracted survival data.