A comprehensive meta - analysis of the subject published in 2007 supports the existence of the correlation .
A comprehensive meta - analysis of the subject published in 2007 concluded that these discrepancies could be resolved when sample size and study design are taken into account .
A comprehensive meta - analysis of the subject published in 2007 supports the existence of the correlation , and concluded that these discrepancies could be resolved when sample size and study design are taken into account .