We can’t know for certain. That’s the idea of systematic biases. There no way to tell if all your trials are slanted in a specific fashion, if the biases also appears in your high quality studies.
On the other hand we have fields such as homeopathy or telephathy (Ganzfeld experiments) where there are meta-analysis that treat all studies mostly equally that find that homeopathy works and telepahty exist. On the other hand you have meta-analysis who try to filter out low quality studies who come to the conclusion that homeopathy doesn’t work and telepathy doesn’t exist.
We can’t know for certain. That’s the idea of systematic biases. There no way to tell if all your trials are slanted in a specific fashion, if the biases also appears in your high quality studies.
On the other hand we have fields such as homeopathy or telephathy (Ganzfeld experiments) where there are meta-analysis that treat all studies mostly equally that find that homeopathy works and telepahty exist. On the other hand you have meta-analysis who try to filter out low quality studies who come to the conclusion that homeopathy doesn’t work and telepathy doesn’t exist.