I'm not sure why that text is showing up red for you? I didnt type it in red and looking at my post now there is no red text. I'm used to making an interaction model like this using proc logistic: MODEL CHLAMYDIA (DESCENDING) = AGE NEW_12M RACE LIFETIME_SEX SEX_12M PAST_CHLAP UNPRO_12M bmi gender bmi*gender Although, I was told that proc surveylogistic doesnt have that capability and even when i tried it SAS set all values for the interaction term bmi*gender to 0. So I decided to dummy code interaction variables by simply combining my 2 variables of interest for the interaction models like this where 0 for each dummy variable is my reference: UNDERF=.; IF GENDER=1 AND BMI=1 THEN UNDERF=1; ELSE IF GENDER=0 AND BMI=2 THEN UNDERF=0; ELSE UNDERF=.; UNDERM=.; IF GENDER=0 AND BMI=1 THEN UNDERM=1; ELSE IF GENDER=0 AND BMI=2 THEN UNDERM=0; ELSE UNDERM=.; HEALTHF=.; IF GENDER=1 AND BMI=2 THEN HEALTHF=1; ELSE IF GENDER=0 AND BMI=2 THEN HEALTHF=0; ELSE HEALTHF=.; OVERF=.; IF GENDER=1 AND BMI=3 THEN OVERF=1; ELSE IF GENDER=0 AND BMI=2 THEN OVERF=0; ELSE OVERF=.; OVERM=.; IF GENDER=0 AND BMI=3 THEN OVERM=1; ELSE IF GENDER=0 AND BMI=2 THEN OVERM=0; ELSE OVERM=.; OBESEF=.; IF GENDER=1 AND BMI=4 THEN OBESEF=1; ELSE IF GENDER=0 AND BMI=2 THEN OBESEF=0; ELSE OBESEF=.; OBESEM=.; IF GENDER=0 AND BMI=4 THEN OBESEM=1; ELSE IF GENDER=0 AND BMI=2 THEN OBESEM=0; ELSE OBESEM=.; and then enter each of those dummy coded interaction variables into my model individually like this: PROC SURVEYLOGISTIC DATA=NO_MISSING; WEIGHT WTMEC2YR; STRATUM SDMVSTRA; CLUSTER SDMVPSU; CLASS RACE (REF='NON-HISPANIC WHITE') UNPRO_12M (REF='NEVER') BMI (REF='HEALTHY WEIGHT (5TH TO <85TH PERCENTILE)') NEW_12M (REF="NO") GENDER (REF='MALE') PAST_CHLAP (REF='NO') AGE(REF='30-34') UNDERM (REF='MALE-HEALTHY') /PARAM=REF; MODEL CHLAMYDIA (DESCENDING) = AGE NEW_12M RACE LIFETIME_SEX SEX_12M PAST_CHLAP UNPRO_12M UNDERM; FORMAT UNDERM UNDERM. NEW_12M NEW_12M. GENDER GENDER. RACE RACE. BMI BMI. PAST_CHLAP PAST_CHLAP. UNPRO_12M UNPRO_12M. AGE AGE.; TITLE 'INTERACTION MODEL BMI AND GENDER'; RUN; I just wanted to check to see if im on the right track with dummy coding in order to study my interactions of interest or if there was an easier way? Im using SAS 9.4
... View more