Meta-analyses in their best form are subject to many biases, but this one seems particularly guilty. It mentions causation only once, in a single sentence refe

Meta-analyses in their best form are subject to many biases, but this one seems particularly guilty. It mentions causation only once, in a single sentence referencing this study. https://dx.doi.org/10.1186/1471-2164-9-77 https://dx.doi.org/10.1186/1471-2164-9-77 13 years is a long time. Have these results been reproduced?