What are the ways to identify a no show new hire

We have few new hires which did not show up for some reasons, however as they were provided with a start date, once they became a regular employee few outbound files/reports picked them as part of active employees. As the report runs each day, we need to understand, is there a way to identify the no show new hires than the regular new hires/active employees so that we can restrict them from further processes. It seems, currently until someone manually updates those employees (cancel workrelationship or terminate the work relationship), they will be treated as regular active employees. Need to