Auditing high-cost claims: critical points

High-cost hospital claims bring together, in a single bill, the elements that place the greatest demands on hospital auditing: clinically complex procedures, materials with a high unit value, prolonged hospital stays and multiple professionals involved. The higher the value of the claim, the greater the financial impact of each denied item.

Auditing these claims follows the same principles as hospital auditing in general, but with stricter documentation requirements and less tolerance for inconsistencies. A missing clinical justification, a missing traceability label or a code incompatible with the recorded diagnosis has, in these claims, disproportionately greater financial consequences than in conventional hospital stays.

Knowing the specific critical points of these claims, by category of care, is the first step in structuring an internal audit capable of protecting revenue where the risk is greatest.

What defines a high‑cost claim

The term “high cost” in the hospital context describes hospital stays and procedures that combine high clinical complexity with a high volume of billable resources. There is no fixed amount that places a claim in this category: what defines it is the density of billable items and the financial impact of each one.

In practice, four profiles account for most of these claims:

• major surgeries using orthotics, prosthetics and special materials (OPME);

• cancer treatments with chemotherapy or immunotherapy;

• prolonged stays in the intensive care unit;

• high-complexity procedures such as transplants and cardiovascular surgeries.

What these profiles have in common is the combination of multiple professionals, materials with a high unit value, continuous-use drugs and specific documentation requirements for each item billed. Each of these variables is a risk point for the audit: any inconsistency between what was recorded, authorized and billed can result in a denial of a substantial amount.

OPME: the highest-risk item in a surgical claim

In major surgeries, OPME materials often account for the largest share of the amount billed. They are also the items that receive the most scrutiny from payer auditors, precisely because of the combination of high unit value and specific documentation requirements.

Three dimensions need to be checked for each OPME item used.

The first is traceability: the Ministry of Health’s Manual of Good Practices for OPME Management requires all professionals involved in the procedure to record complete information about each material in the surgical report, the operating room consumption record and the patient’s medical record, including the product name, manufacturer, size, quantity and a description of the implant performed.

The second is compliance with the authorization: the materials billed must correspond exactly to what the payer authorized, with documented clinical justification for any substitution or addition.

The third is consistency between the material prescribed and the one actually implanted, which can be verified by cross-checking the physician’s order, the surgical report and the invoice.

What regulations require for OPME traceability

Anvisa (National Health Surveillance Agency) RDC No. 14/2011 establishes that each implantable material or system component must come with traceability labels, with one copy that must be affixed to the clinical record, one to be inserted in the document given to the patient and one to be attached to the tax documentation.

The absence of any of these copies is, on its own, sufficient grounds for denying the corresponding material, regardless of whether it was actually used.

Cancer and high-complexity treatments: what to audit

Cancer-related hospital stays and high-complexity treatments have a specific risk profile: treatment protocols are long, involve multiple cycles and combine high-cost drugs with supportive procedures that need to be individually justified in the claim.

The critical points for auditing these claims are:

Consistency between the recorded ICD code and the prescribed treatment regimen

The diagnosis documented in the medical record must technically support the protocol used, including the line of therapy and the choice of drug. Discrepancies between the ICD code and the protocol are a frequent reason for denials in cancer claims.

Dosage and number of cycles billed versus administered

The charge must accurately reflect what was actually administered to the patient, with each administration recorded in the medical record. Charges for cycles with no record of administration are frequently denied and rarely reversed, due to a lack of contemporaneous clinical evidence.

Prior authorization for high‑cost drugs

Immunobiologics, targeted therapies and other restricted-use drugs require prior authorization from the payer before administration. The audit must verify that the authorization was valid at the time of administration and that the authorized drug matches the one billed.

Clinical protocol that justifies the treatment regimen

For high-complexity therapies, the payer may question the appropriateness of the protocol adopted. A documented clinical protocol, preferably based on recognized national or international guidelines, strengthens the claim and reduces the risk of a technical denial.

ICU stays: where the claim grows by the day

Intensive care unit stays accumulate billable items every shift: daily rates, monitoring fees, continuous-use drugs, medical gases, bedside procedures and single-use materials. The volume of daily entries and staff turnover create conditions for recording inconsistencies that pile up over the course of the stay.

The critical points for auditing ICU claims are:

• Consistency between the level of care recorded and the one billed: the daily rate charged must correspond to the type of ICU where the patient was admitted (adult, neonatal, coronary, among others), with a medical record entry that supports the classification. Changes in level of care during the stay need to be documented with the date and clinical justification.

• Recording bedside procedures: every procedure billed as performed at the bedside, such as intubation, tracheostomy, central line placement or puncture, must be recorded in the medical record with the date, time, responsible professional and clinical indication. The absence of any of these elements is direct grounds for a denial.

• Billing for medical gases: oxygen, compressed air and other gases are billed daily in the ICU and often show inconsistencies between the volume administered and the volume billed. The audit must check for consistency between the order, the administration record and the entry in the claim.

• Checking for duplicates between shifts: shift changes are risky moments for duplicate entries, especially for continuous-use drugs and materials used daily. The audit must cross-check each shift’s administration records against the corresponding entries in the claim.

CFM Resolution No. 2,448/2025 and its impact on high‑cost denials

Published in October 2025, CFM (Federal Council of Medicine) Resolution No. 2,448/2025 redefines the rules of medical auditing in Brazil and brings a protection directly relevant to high-cost claims: procedures pre-authorized by the payer and actually performed cannot be denied.

The rule further establishes that payers’ accreditation programs cannot be used to interfere with clinical conduct or serve as grounds for denying procedures, tests, therapies and consultations, including the denial of OPME coverage or disputes over physician fees, daily rates and hospital fees. In high-cost claims, where each item’s individual value is substantial, this protection has a direct financial impact.

This regulatory protection, however, presupposes accurate documentation. A procedure that was authorized, performed and correctly recorded is explicitly protected against denial. A procedure without proper records loses that protection, even when it was clinically necessary.

In high-cost claims, documentation is revenue protection

The financial risk in high-cost claims lies not only in clinical complexity but in the density of items that need to be individually justified, recorded and consistent with one another. An inconsistency that would lead to a low-value denial in a conventional hospital stay can mean a substantial loss in a surgery with OPME or an immunotherapy cycle.

Hospitals with a significant volume of high-complexity stays need a structured internal audit to cover this type of claim with the rigor it requires.

Rivio applies artificial intelligence to audit 100% of hospital claims, automatically identifying inconsistencies between the medical record, the authorization and billing before submission to the payer, with expert supervision at every step of the process.

Frequently asked questions about auditing high‑cost claims

What are high-cost hospital claims?

High-cost claims are hospital stays and procedures that combine high clinical complexity with a high volume of billable items. The most common profiles include major surgeries using OPME, cancer treatments, prolonged ICU stays and high-complexity procedures such as transplants and cardiovascular surgeries.

Why do high-cost claims carry a higher risk of denial?

The combination of multiple billable items, materials with a high unit value and specific documentation requirements increases the likelihood of inconsistencies between what was recorded, authorized and billed. The higher the value of the claim, the more closely the payer’s auditor examines each item.

What should the audit check in surgeries with OPME?

The audit should check three dimensions: traceability of the material (labels in the medical record, invoice and surgical report), compliance with the prior authorization and consistency between the material prescribed and the one actually implanted. The absence of any of these elements is direct grounds for a denial.

Can pre-authorized procedures be denied?

CFM Resolution No. 2,448/2025 establishes that procedures pre-authorized by the payer and actually performed cannot be denied. The rule also prohibits using accreditation programs as grounds for denying procedures or OPME or for disputing physician fees and hospital fees.

How does internal auditing protect revenue in high-cost hospital stays?

Internal auditing identifies inconsistencies before the claim is submitted to the payer, when it is still possible to correct records, supplement documentation and align billing with what was actually performed and authorized. In high-cost claims, this upfront control reduces the volume of denials and the effort spent on denial appeals after submission.