How is a "serious complaint" defined?

The MQSA Regulations [900.2(tt)] define a serious complaint as a report of a serious adverse event, which means an adverse event that may significantly compromise clinical outcomes or one for which a facility fails to take appropriate corrective action in a timely manner. Examples of adverse events that fall under MQSA regulations include: poor image quality; the use of personnel that do not meet the applicable requirements of 900.12 (a); and failure to send mammography reports within 30 days to the referring physician or in a timely manner to the self-referred patient.