'All cause' measure overinflates readmission rates 25%

Despite being the basis for the publicly reported Centers for Medicare & Medicaid Services quality measure, "all cause" readmissions may be a misleading gauge, according to a new study from the University of California, San Francisco Medical Center.

Neurological orthopedic surgeons found that all cause readmission rates overestimate unplanned readmissions by up to 25 percent because they fail to differentiate between planned, scheduled, staged and unplanned surgeries for complications.

"Publicly reported 'all cause' readmission rates may not be realistic. To be accurate, substantial drill down of readmission rates is needed to find clinically relevant causes," senior author Praveen Mummaneni, codirector of the Spinal Surgery and UCSF Spine Center, said in a statement.

Including planned rehospitalizations for spinal surgeries in the national algorithm for readmission rates ultimately could impact patient care. Surgeons will have to decide whether to schedule multiple surgeries, which usually improves safety and effectiveness, or schedule single surgeries, which would improve readmission rates, the study authors noted.

Overestimated all cause readmissions also could influence hospital reimbursement rates, as well consumer perception of care quality.

With such quality repercussions, the UCSF study reinforces an American Hospital Association report last September that indicated readmission rates were an "ill-suited" quality indicator in that not all readmissions can (or should) be avoided.

In addition to issues with calculating hospital readmissions, research last October found that models used to predict readmissions perform poorly and don't account for variables associated with overall health and function, illness severity or social determinants of health.

To learn more:
- read the UCSF announcement 
- check out the study abstract (.pdf)