对GWAS的summary文件进行整合时,经常需要在beta,or, se, p, zscore之间进行换算,故在此总结一下。希望对大家有帮助。
1. se 计算
1.1 有 beta、p ,计算se;
se=sqrt(((beta)^2)/qchisq(p,1,lower.tail=F))
1.2 有 or、p ,计算se;
se=abs(log(or)/qnorm(p/2))
2. zscore计算
2.1 有 beta、p ,计算zscore;
c=-qnorm(p/2)
情况1:beta > 0,zscore = c
情况2:beta < 0,zscore = -c
2.2 有 or、p ,计算zscore;
c=qnorm(1-p/2)
情况1:or > 1,zscore = c
情况2:or < 1,zscore = -c
2.3 有 beta、se ,计算zscore;
zscore=beta/se
2.4 有 or、se ,计算zscore;
zscore=log(or)/se
注意:这里的se指的是log(or)的se,plink给出的se就是默认log(or)的se
3 beta 和 OR 的转换
beta to OR:
Beta= log(OR)
Assuming the confidence interval being used is 95%,the upper and lower bounds for the OR:
upper bound of OR = OR + se(OR) x 1.96
lower bound of OR = OR - se(OR) x 1.96
Log(upper bound of OR) = upper bound of beta
Log(lower bound of OR) = lower bound of beta
upper bound of beta = beta + se(beta) x 1.96
lower bound of beta = beta - se(beta) x 1.96
If you have the 95% C.I of beta, then calculating the SE(beta) is quite simple!
for example if beta = 0.5 and the upper C.I is 0.6 then
upper C.I of beta = beta + se(beta) x 1.96
0.6 = 0.5 + se x 1.96
以上所有的公式换算均在R环境下完成的。
此文感谢彭师姐和蔡大胖同学参与的讨论,以及 https://www.researchgate.net/post/How_can_I_calculate_beta_coefficient_and_its_error_from_Odds_Ratio_from_GWAS_summary_Statisitcs