highly significantP < 10−6
Specifically, the evidence grading criteria were as follows: If the association was supported by a highly significant random-effects ( P < 10−6, a threshold considered to substantially reduce false positive findings) 10 – 13 , a sample size of more than 1000 cases, P < 0.05 in the largest study, I2 < 50%, absence of small study effects, a PI excluding the null, no evidence of excess significance bias, and P < 0.05