Nowadays, no-one questions the role of non-invasive ventilation (NIV) in the routine practice of a pulmonology department. However, despite its widespread use, we encounter serious difficulties when coding this intervention in the diagnosis-related groups (DRG). As we know, the DRG system groups patients with similar clinical characteristics and resource requirements into categories. In Spain, we have been using the All Patient Refined-DRG (APR-DRG) since 1997, which provides an additional 4 severity levels and 4 mortality risk levels.1 The main problem is that no DRGs specifically mention NIV.

Criner et al.2 drew attention to this problem in 1995, when they reported that failure to allocate the real cost of NIV could prevent hospitals from obtaining reimbursement for this treatment. Other authors have alerted us to the urgent need for incorporating NIV in DRG coding to prevent a situation in which clinicians, compelled by their managers, may even prefer to intubate patients rather than apply NIV, in order to receive greater reimbursement.3,4

We have reviewed version 25.0 of the DRG definitions manual,1 and found that NIV is not mentioned at all. The term “invasive mechanical ventilation” is specified in only 2 DRGs: 881 (respiratory system diagnosis with mechanical ventilation more than 96h) and 882 (respiratory system diagnosis with mechanical ventilation less than 96h). The term “mechanical ventilation for certain clinical situations” appears as a procedure classified as a major complication or comorbidity (CC) in other disease entities. This is the case for DRG 588 (bronchitis and asthma, age <17 years with major CC), 589 (bronchitis and asthma, age <18 years with major CC), 540 (respiratory infections and inflammations except uncomplicated pneumonia with major CC), and 541 (uncomplicated pneumonia and other respiratory disorders except bronchitis, asthma with major CC) (Table 1).

If NIV is administered to a patient with obesity hypoventilation syndrome, things become even more complicated. The term “hypoventilation” does not figure in the manual, and the term “obesity” only appears in surgical DRG 288 (gastric procedures for obesity). However, the term “respiratory failure” appears as a CC in many other diseases.

How, then, are DRGs being applied for patients seen on the pulmonology ward? How do we code our discharge reports? Is it correct to include NIV administered to hypoventilated patients in DRG 588? Should severely ill patients who receive NIV for more than 96h be classified as DRG 881? Could this failure to provide clear criteria lead to local arrangements in different hospitals, meaning that different DRGs are applied to the same diseases and procedures? We firmly believe that NIV needs to be included as a separate entity in DRG manuals. This would give NIV recognition as a product, and allow this therapeutic tool to be correctly valued.