Title



     ivasmm -- Additive structural mean model



Description



    ivasmm is not a command. This helpfile is to note that the additive structural mean model
    (ASMM) is simply fit with a linear IV estimator available in ivregress or ivreg2 or even
    implemented yourself with gmm.



For a binary outcome the ASMM estimates a causal risk difference.



Examples



    Read in binary outcome data; y outcome, x exposure, w covariate, z* instrumental variables
    (genotypes).



        . use https://raw.github.com/remlapmot/ivonesamplemr/main/data/ivbinoutdata, clear



    Fit the model with a single instrumental variable.



        . ivregress 2sls y (x = z1)
        . ivreg2 y (x = z1)



    Fit the model with multiple instruments.



        . ivregress 2sls y (x = z1 z2 z3)
        . ivreg2 y (x = z1 z2 z3)



    Fit the model with multiple exposures, and instruments, and adjusting for w.



        . ivregress 2sls y w (x1 x2 = z1 z2 z3)
        . ivreg2 y w (x1 x2 = z1 z2 z3)



References



    Clarke PS, Palmer TM, Windmeijer F.  Estimating structural mean models with multiple
        instrumental variables using the Generalised Method of Moments.  Statistical Science,
        2015, 30, 1, 96-117.  DOI



    Palmer TM, Sterne JAC, Harbord RM, Lawlor DA, Sheehan NA, Meng S, Granell R, Davey Smith G,
        Didelez V.  Instrumental variable estimation of causal risk ratios and causal odds ratios
        in Mendelian randomization analyses.  American Journal of Epidemiology, 2011, 173, 12,
        1392-1403.  DOI



    Robins JM.  The analysis of randomised and nonrandomised AIDS treatment trials using a new
        approach to causal inference in longitudinal studies.  In Health Service Research
        Methodology: A Focus on AIDS (L. Sechrest, H. Freeman and A. Mulley, eds.).  1989.
        113–159. US Public Health Service, National Center for Health Services Research,
        Washington, DC.



Author



INCLUDE help ivonesamplemr-author