Title



     ivxtile -- Perorm estimation within quantiles of the first stage residuals prefix command



Syntax



        ivxtile , par(string) [saving(filename [, replace]) xtile_options]: iv_cmd



    options                         Description
    ----------------------------------------------------------------------------------------------
      par(string)                   Parameter from the iv_cmd (ivreg2, ivmsmm, ivlsmm, ivtsps,
                                      ivtsri) to collect
      saving(filename [, replace])  Save the within quantile estimation results to a dataset.
                                      Specify replace to overwrite an existing dataset
      trace                         View the output from the iv_cmd in each quantile
      xtile_options                 xtile##options



Description



    ivxtile implements the command specified after the prefix within quantiles of the first stage
    residuals, as per Burgess et al., 2014.



Options



    Please see xtile##options



Examples



    Simulate data with different outcome-exposure relationships; y# outcome, x exposure, g
    instrumental variable (genotype).



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



    Plot outcome-exposure relationships



        . twoway line y1 x, sort(x)
        . twoway line y2 y3 y4 x, sort(x)
        . twoway line y5 x, sort(x)



    Use with different iv commands.



        . ivxtile, nq(5) par(x): ivregress 2sls y2 (x = g)
        . ivxtile, nq(10) par(b1): ivtsps y2 (x = g)



    Some binary outcome examples.



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



        . ivxtile, nq(5) par(b1): ivtsps y (x = z1 z2 z3), link(logadd)
        . ivxtile, nq(5) par(b1): ivtsps y (x = z1 z2 z3), link(logmult)
        . ivxtile, nq(5) par(b1): ivtsps y (x = z1 z2 z3), link(logit)
        . ivxtile, nq(5) par(b1): ivtsri y (x = z1 z2 z3), link(logadd)
        . ivxtile, nq(5) par(b1): ivtsri y (x = z1 z2 z3), link(logmult)
        . ivxtile, nq(5) par(b1): ivtsri y (x = z1 z2 z3), link(logit)
        . ivxtile, nq(5) par(x): ivlsmm y (x = z1 z2 z3)
        . ivxtile, nq(5) par(x): ivmsmm y (x = z1 z2 z3)



    Save the dataset of results.



        . ivxtile, nq(10) par(x) saving(ivxtileres): ivreg2 y2 (x = g)



Stored results



    ivxtile does not store results in either e() or r() but does save the results dataset if the
    saving() option is specified.



References



    Burgess S, Davies N, Thompson SG, EPIC-InterAct Consortium.  Instrumental variable analysis
        with a nonlinear exposure-outcome relationship.  Epidemiology, 2014, 25, 6, 877-885.  DOI



    StataCorp. Stata Base Reference Manual. Release 16.  pctile - Creating variable containing
        percentiles. 2016.  URL



Author



INCLUDE help ivonesamplemr-author