The PSMATCH Procedure

PSMODEL Statement

PSMODEL treatvar <(TREATED='level' )> = <effects> </ WEIGHT= weight> ;

The PSMODEL statement specifies the logistic regression model for computing the propensity score. Either the PSMODEL statement or the PSDATA statement is required to obtain the propensity scores.

The treatment indicator variable treatvar must be a binary classification variable that is listed in the CLASS statement. You can specify the following options:

TREATED='level': models the probability of the specified treated level. If this option is not specified, PROC PSMATCH models the probability of the first ordered level based on the formatted values.
effects: are the explanatory effects, which can include variables, main effects, interactions, and nested effects for the logistic regression model.
WEIGHT=weight: specifies a variable that contains the weight of each observation that is used in fitting the logistic regression model to derive the propensity scores. These weights should not be confused with weights derived from the propensity scores by the PSMATCH procedure.