I am trying to run Poisson regression using the National Nutrition and Health Examination Survey data. The SAS institute has released a document "Poisson Regressions for Complex Surveys" (https://support.sas.com/rnd/app/stat/examples/SurveyPoisson/surveypoisson.htm). However I am having some difficulties effectively applying this program.   I copied the program and used the sample data they provided on the webpage and it didn't work. The program starts after section 3a. For example:   data converged; set converge(where=(Status=0 & full=0)); run;   The actual dataset "converge" has no "full" variable with value '0' thus the database "converged" contains no observation.   Please see attached log file. I have made efforts by sorting the merge database with the by variable (highlighted in blue). but it still didn't work.   The problem starts from page 19, then pages 21 to the end. I have highlighted all issues in yellow color .   I'd be most greatful for any advice!! ... View more