Half of patient safety events, patient harms go unreported

Half of patient harms go unreported

According to the 2025 OIG report, 49% of the patient harms that happened in October 2018 went unreported. These missed events were absent from all of a hospital's monitoring or surveillance systems, regardless of whether the organization was aware they had occurred.

Notably, this figure is actually an improvement from years previous. In 2012, OIG found that hospitals did not capture 86% of patient safety events, indicating that hospitals have improved their systems for capturing and reporting errors and harms.

But although the 49% number is an improvement in patient safety reporting, the OIG authors stressed that hospitals are still missing opportunities to improve patient care. Each missed harm event is a lost opportunity to understand and potentially reconsider a system that caused the event.

Why are patient harm events going unreported?

Most of the time, hospital staff didn't even know a certain incident constituted a patient safety event that needed to be reported, the OIG report found.

For instance, hospital staff did not consider 46% of missed patient safety events to be harm.

"They considered these events as part of the normal course of patient care, such as known complications and side effects from treatment," the report authors explained.

Another 20% of staff said they could not distinguish the patient safety event from the patient's underlying disease, while 16% said it was not standard practice to report a certain patient safety event. For 8% of the missed patient safety events, staff said their surveillance and reporting systems should have captured the issue. Finally, for 4% of the missed events, reporting lapsed because it occurred after discharge.

The crux of the issue is defining patient safety events, OIG asserted.

When reviewing procedures and guidelines at the studied hospitals, OIG found a smattering of different references from CMS, states and accreditation organizations defining patient safety events.

"As a result, definitions of harm events vary widely across hospitals," OIG said. "This means that a harm event reportable at one hospital may not be considered reportable in another hospital, which undermines reliable measurement of the extent of patient harm across hospitals."

OIG also found that hospitals are more likely to miss patient harm events linked to surgeries or procedures than non-surgical harm events, while they are equally as likely to miss adverse events versus temporary harm events.

What types of patient safety events are reported?

While just around half of patient safety events go unreported in hospitals, OIG did point out that 35% do get captured.

The most common strategy for flagging patient harms was through a manual medical record review. Medical record reviews are labor-intensive, the OIG authors noted, meaning they might not be the most reliable method for detecting patient safety events.

Hospitals also used real-time patient monitoring systems, like automated alerts, to give bedside patient safety alerts. Tools like these are useful for sepsis monitoring, OIG offered as an example.

Finally, hospitals were likely to use hospital incident reporting systems that monitor patient safety trends and trigger an investigation or follow-up activities when appropriate.

But even when patient safety events do get reported, they don't usually result in the appropriate follow-up. Only 17 of the reported events OIG assessed were investigated by the hospital, "limiting opportunities for hospitals to make patient safety improvements to reduce the risk of future harm," the agency said. "Investigations allow hospitals to identify system breakdowns, negligence, or errors that may have contributed to the event."

All said, there were 266 harm events in hospitals in October of 2018, and only 94 were captured. Of those, only 17 were investigated by the hospital and then only 11 led to patient safety improvements.

Furthermore, hospitals told patients about one-third of the harm events that happened to them, and although disclosure is not mandated, OIG pointed out that this can limit the organization's ability to make things right with patients.

"Disclosing harm events to patients is considered a best practice that can increase accountability and improve investigations when patient perspectives are included," OIG said. "It can also improve the care experience and support patients' engagement in the decision-making about their care."

Recommendations moving forward

Improving patient safety and reporting requires a multidisciplinary approach, but OIG centered many of its recommendations on relevant federal agencies. For example, OIG advised the Agency for Healthcare Research and Quality and CMS to leverage their federal partnerships to align harm event definitions.

CMS might also more strongly enforce certain requirements, such as the Medicare Quality Assurance and Performance Improvement, to fortify hospital accountability.

Finally, OIG suggested CMS have its Quality Improvement Organizations use patient harm information to assist hospitals in understanding and improving their safety reporting systems.

Sara Heath has reported news related to patient engagement and health equity since 2015.