Title



     mrivests -- Generate genotype specific instrumental variable ratio (Wald) estimates in a
dataset



Syntax



        mrivests varname_gd varname_gdse varname_gp [varname_gpse varname_cov] [if] [in] [,
                options]



    options                      Description
    ----------------------------------------------------------------------------------------------
      generate(varlist, replace) Variables to contain IV estimates and SEs or CI limits
      *                          options passed to mrratio



Description



    mrivests calls mrratio to put the instrumental variable ratio (Wald) estimate and its standard
    error in the variables specified.



    varname_gd is a variable containing genotype-disease (SNP-outcome) association estimates.



    varname_gdse is a variable containing the standard errors of the genotype-disease
    (SNP-outcome) association estimates.



    varname_gp is a variable containing genotype-phenotype (SNP-exposure) association estimates.



    varname_gpse is a variable containing the standard errors of the genotype-phenotype
    (SNP-exposure) association estimates.



    varname_cov is a variable containing the covariance between the genotype-disease (SNP-outcome)
    and the genotype-phenotype (SNP-exposure) estimates.



Options



    generate(varlist, replace) specifies the variables (2 or 3) to contain the IV estimates and
        their standard errors or confidence interval limits. Specifying replace replaces the
        values in these variables if they already exist in the dataset.



    * options passed through to mrratio, e.g. nome.



Examples



    Using the data provided by Do et al. (2013) generate genotype specific estimates for the LDL-c
    phenotype.



    Setup
        . use https://raw.github.com/remlapmot/mrrobust/master/dodata, clear



    Select observations (p-value with exposure < 10^-8)
        . gen byte sel1 = (ldlcp2 < 1e-8)



    Generate IV estimates in dataset
        . mrivests chdbeta chdse ldlcbeta ldlcse if sel1==1, generate(ivest ivse)



    Generate IV estimates with SEs assuming NOME
        . mrivests chdbeta chdse ldlcbeta if sel1==1, generate(ivest ivse, replace) nome



    Generate IV estimates with CI limits using Fieller's Theorem
        . drop ivest
        . mrivests chdbeta chdse ldlcbeta ldlcse if sel1==1, generate(ivest ivcilow ivciupp)
            fieller



References



    Do et al., 2013. Common variants associated with plasma triglycerides and risk for coronary
        artery disease. Nature Genetics. 45, 1345-1352.  DOI



Author



INCLUDE help mrrobust-author