According to current case law, sick days or other information about the duration of an incapacity to work should only be included in the reference in special individual cases. As a rule, this also applies in the case of long-term illness.
In principle, the relationship between sick days and the duration of the employee's employment plays a role for the labor courts. Only if the duration of the incapacity to work has reached a significant level or is essential for the employee's assessment basis may sick days be listed in the reference.