Objective

To estimate the additional hospital costs associated with inpatient medical harms occurring during an index inpatient admission and costs from subsequent readmissions within 90 days.

Data Source

2009 to 2011 Healthcare Cost and Utilization Project's State Inpatient Databases from 12 states.

Study Design

We compare hospital costs incurred by patients experiencing a specific harm during their hospital stay to the costs incurred by similar patients who did not experience that harm.

Data Extraction

We extracted records for adult patients admitted for a reason other than rehabilitation or mental health, were at risk of a harm, and were admitted for less than a year.

Principal Findings

The costliest inpatient harms, such as surgical site infections and severe pressure ulcers, are associated with approximately $30 000 in additional index stay costs per harm. Less costly harms, such as catheter‐ or hospital‐associated urinary tract infections and venous thromboembolism, can add $6000 to $13 000. Birth and obstetric traumas add as little as $100.

Conclusions

Our analysis represents rigorous estimates of the hospital costs of a variety of inpatient harms; these should be of interest to health care administrators and policy makers to identify areas for cost savings to the health care system.