What defines an adverse event in healthcare?

In everyday life, an adverse event can be something trivial, like a flat tire or a broken glass. In the hospital setting, however, the term takes on a critical dimension: it refers to an incident that results in unintended harm to the patient, associated with the care provided rather than with the natural course of the disease.

It is a rigorous technical concept, central to patient safety policies and regulations. Understanding its causes is essential to protect the individual, mitigate legal risks, reduce financial losses and strengthen clinical governance.

What does adverse event formally mean?

In the field of patient safety, an incident is any care-related event that poses a risk or causes harm. If there is no clinical harm, it is classified as a “no-harm incident” (or a near miss, when the failure is caught before it reaches the patient). When there is harm, the occurrence is formally classified as an adverse event.

In Brazil, this concept is governed by Anvisa (National Health Surveillance Agency) RDC No. 36/2013, which established mandatory actions for patient safety, including the creation of Patient Safety Centers (NSPs) and ongoing reporting through Notivisa. Systematic reporting is not just for statistics: it underpins public policy and guides institutional interventions to raise the quality of care.

What does the picture of adverse events in Brazil look like?

According to Notivisa (Anvisa) data, 368,895 healthcare‑related incidents were reported in the country in 2023. The regional breakdown shows a concentration in the Southeast (39.9%), followed by the Northeast (24.6%), South (18.7%), Center-West (12.6%) and North (4.3%).

Recurring reporting indicates regulatory maturity and a growing culture of transparency, but it reinforces the need for institutional responses to this adverse data.

What are the most frequent types of adverse events?

The 2023 data show that most reports occur in hospitals, followed by dialysis services and outpatient clinics. The incident profile reveals two critical areas of attention:

• Direct care failures: intraoperative events, clinical complications and falls.

• Process and operational failures: laboratory errors, failures in administering diets and problems in organizing care.

Patient safety depends on the rigor of workflows and protocols. Failures in these systems are often more decisive in causing errors than individual technical errors by the medical and nursing staff.

What does the degree of harm reveal about care?

The classification of incidents in 2023 shows a predominance of mild and moderate events, as well as a significant volume of no-harm occurrences. This points to a healthy reporting culture, where people learn from mistakes before they escalate.

However, severe cases and deaths are still concentrated in critical moments, such as invasive procedures and ventilatory support (for example, accidental extubation and aspiration).

From a management standpoint, the degree of harm is a gauge of institutional maturity: a high proportion of severe events suggests structural failures in protocols or in clinical supervision.

What are “never events” and why do they demand zero tolerance?

Never events are catastrophic and entirely preventable events that should not happen if basic protocols are followed. In 2023, Brazil reported, among others:

• 176 cases of unintentionally retained foreign objects after surgery;

• 47 surgical procedures performed on the wrong side of the body;

• 114 cases of suicide or attempted suicide with serious injury while in care.

These episodes are not clinical variations but serious breaches of safety barriers. Beyond the irreparable human harm, they have drastic financial and reputational consequences, often resulting in litigation and loss of accreditation.

The Rivio view

Adverse events do not affect safety alone; they disrupt the average length of stay, raise care costs and undermine the predictability of the revenue cycle.

At Rivio, we apply artificial intelligence to turn passive reporting into operational intelligence. By continuously analyzing care workflows and cross-checking regulatory data against clinical records, our technology helps identify risk patterns and anticipate deviations. This approach connects patient safety to financial efficiency and turns risk management into a strategic advantage for the hospital.