There is a need to better understand how comorbidity and frailty affect people with RMDs. Comorbidity usually increases with age, with the elderly and frail most affected. Often, patients with RMDs gather comorbidities that can have a negative effect on achieving both early diagnosis but also good responses to treatment. Some early data suggest that certain types of comorbidity may be seen in certain groups of people. Furthermore, although evidence suggests that comorbidities reduce the chances of good treatment responses, it remains unclear whether this is due to direct effects of comorbidities on RMDs, or through other mechanisms, such as for example the concurrent use of multiple medications.