The variable in the FREQ statement identifies a variable that contains the frequency of occurrence of each observation. PROC SURVEYLOGISTIC treats each observation as if it appears n times, where n is the value of the FREQ variable for the observation. If it is not an integer, the frequency value is truncated to an integer. If the frequency value is less than 1 or missing, the observation is not used in the model fitting. When the FREQ statement is not specified, each observation is assigned a frequency of 1.
If you use the events/trials syntax in the MODEL statement, the FREQ statement is not allowed because the event and trial variables represent the frequencies in the data set.
If you use the FREQ statement and specify the VARMETHOD=BRR or VARMETHOD=JACKKNIFE option to estimate the variance, then you must identify the primary sampling units with a CLUSTER statement unless you also provide replicate weights with a REPWEIGHTS statement.