Test for Conditional Independence of X-covariate Distributions from Treatment Selection within Given, Adjacent PS Bins. The second step in Supervised Propensity Scoring analyses is to verify that baseline X-covariates have the same distribution, regardless of treatment, within each fitted PS bin.
SPSbalan(envir, dframe, trtm, yvar, qbin, xvar, faclev = 3)The local control environment
Name of augmented data.frame written to the appn="" argument of SPSlogit().
Name of the two-level treatment factor variable.
The outcome variable.
Name of variable containing bin numbers.
Name of one baseline covariate X variable used in the SPSlogit() PS model.
Maximum number of different numerical values an X-covariate can assume without automatically being converted into a "factor" variable; faclev=1 causes a binary indicator to be treated as a continuous variable determining a proportion.
An output list object of class SPSbalan. The first four are returned with a continuous x-variable. The next 4 are used if it is a factor variable.
aovdiffANOVA output for marginal test.
form2Formula for differences in X due to bins and to treatment nested within bins.
bindiffANOVA output for the nested within bin model.
df3Output data.frame containing 3 variables: X-covariate, treatment and bin.
factabMarginal table of counts by X-factor level and treatment.
tabThree-way table of counts by X-factor level, treatment and bin.
cumchiCumulative Chi-Square statistic for interaction in the three-way, nested table.
cumdfDegrees of-Freedom for the Cumulative Chi-Squared.
Cochran WG. (1968) The effectiveness of adjustment by subclassification in removing bias in observational studies. Biometrics 24: 205-213.
Obenchain RL. (2011) USPSinR.pdf USPS R-package vignette, 40 pages.
Rosenbaum PR, Rubin RB. (1983) The Central Role of the Propensity Score in Observational Studies for Causal Effects. Biometrika 70: 41-55.
Rosenbaum PR, Rubin DB. (1984) Reducing Bias in Observational Studies Using Subclassification on a Propensity Score. J Amer Stat Assoc 79: 516-524.