/* Unadjusted OR from logistic regression HOSP*/ PROC LOGISTIC DATA= MB2; CLASS VAR4(PARAM = REF REF = '1') VAR2 (PARAM = REF REF = '1') VAR6 (PARAM = REF REF = '1') VAR10(PARAM = REF REF = '3'); MODEL VAR7(EVENT = '1') = VAR4; RUN; this is the unadjusted odds ratio code im running   its saying invalid reference value for VAR4   ... View more