Connecting the causes and codes for pneumonia

The rules that govern code assignment for pneumonia bear little relationship to long-accepted clinical documentation practices.

Diagnosis and clinical management of pneumonia are difficult, but meeting documentation requirements and accurately conveying the severity and complexity of a pneumonia patient's condition are even more challenging.


The rules that govern code assignment bear little relationship to long-accepted clinical documentation practices for pneumonia. Clinicians frequently dismiss these additional documentation needs as a nuisance that has no relevance to clinical care. They don't realize that by disregarding the code assignment rules, they are not expressing how truly sick their patients are, which can have devastating consequences for quality of care reporting, outcome measures, and reimbursement.

The diagnosis of pneumonia is first and foremost clinical, based on symptoms and physical examination. Chest X-ray is expected to show an infiltrate or consolidation, but its appearance is occasionally delayed. Often the chest X-ray demonstrates an abnormal finding that may have a cause other than pneumonia. In rare instances, symptoms and examination strongly indicate pneumonia but no obvious abnormality is seen on X-ray. In this situation, clinicians need to clearly state that the X-ray is unremarkable but pneumonia is substantiated by clinical findings.

One of the most important pneumonia documentation issues relates to health care-associated pneumonia (HCAP). HCAP is defined by the patient's exposure to certain high-risk settings (Table 1). Once HCAP is recognized, clinicians also need to specify a probable, likely, or suspected organism in all cases.

Evidence-based literature and pneumonia guidelines from the Infectious Diseases Society of America (IDSA) clearly show that the organisms predominantly causing HCAP (80% to 85% of cases) are gram-negative bacteria and Staphylococcus species (both methicillin-resistant and methicillin-sensitive). Hence it is imperative to treat affected patients with a full course of antibiotics active against these organisms unless culture results dictate otherwise. The same principle applies to ventilator-associated pneumonia (VAP) and hospital-acquired pneumonia (HAP).

Every clinician, informed by published medical literature and IDSA guidelines, really knows what the probable, suspected, or likely organisms causing HCAP are, although the organism or organisms commonly go unstated. But since clinicians base their choice of antibiotics on this knowledge, objecting to documenting this good clinical judgment and practice has no rational basis.

Some clinicians are reluctant due to a mistaken belief that documenting a suspected, but unconfirmed, condition based on solid clinical grounds is somehow prohibited. Quite to the contrary, this sort of judgment is an important professional skill that we exercise all the time in medicine. In addition, CMS regulations specifically recognize this practice for inpatient documentation and for coding of the greatest diagnostic specificity, provided that a full course of treatment is given for the suspected condition as if it had been confirmed.

We are also fortunate that the coding classification provides a code for unspecified “gram-negative” pneumonia, since it would be almost impossible to determine the specific gram-negative bacteria that were the most likely or suspected cause when cultures are negative (except perhaps for Pseudomonas in some cases where it is highly likely). Similarly, suspected Staphylococcus does not have to be specified as methicillin-resistant or methicillin-sensitive.

What happens when clinicians do not document the suspected organism or organisms causing HCAP? Unless the suspected or confirmed organism is stated, coding rules will classify these HCAP patients, like those with community-acquired pneumonia (CAP), as having “simple” pneumonia, with low severity of illness and low mortality, low complication rates, low cost of care, and a short expected length of stay. But HCAP, in contrast to CAP, is associated with high mortality, high complication rates, high cost of care, and longer expected length of stay, reflecting much greater severity of illness.

Imagine the impact on quality reporting if a clinician ignores this important documentation imperative. His or her very sick patients with HCAP will be analyzed and reported together with not-so-sick CAP patients, resulting in mortality and complication rates 300% to 400% higher than expected and the appearance of a miserable quality of care.

The good clinical and documentation practice of specifying the suspected organism will allow cases of HCAP to be separately classified by precise coding as severe, “complex” cases of pneumonia, reflecting the higher severity of illness and resulting in accurate analysis and reporting of quality of care.

Another important component of pneumonia documentation is to identify and document aspiration pneumonia or pneumonitis, both of which have therapeutic, management, and coding implications. These can be CAP, HAP, or HCAP, the last being the most common. Note that cases of apparent VAP occurring following intubation, sometimes delayed in appearance for more than 48 hours, may actually be due to the patient aspirating during the procedure and represent aspiration pneumonia rather than VAP. If that is the case, clarify that in the medical record.

Clinical indicators suggesting aspiration pneumonia are shown in Table 2. The more indicators that are present, the greater the likelihood of aspiration. Don't be fooled by a negative bedside swallowing evaluation or imaging study, which cannot be relied upon to rule out aspiration. Only a positive study has diagnostic value.

Aspiration pneumonia (implying infection), aspiration pneumonitis (suggesting chemically induced injury and inflammation), and even aspiration bronchitis are all classified as “complex” pneumonias, having a high severity of illness, similar to gram-negative and staphylococcal pneumonia. Specific documentation of aspiration pneumonia, pneumonitis, or bronchitis is needed since “aspiration” alone is classified as a toxic effect of a foreign body in the respiratory tract, representing a lower severity of illness.

Now, what about CAP? Documentation of the confirmed or suspected organism is encouraged, but unfortunately it is virtually impossible to distinguish the most likely candidate among the multiple causative organisms when cultures and other confirmatory tests are negative. However, for CAP there are no practical implications of not documenting a suspected organism. In most cases, CAP will properly be classified as a “simple” pneumonia with low severity of illness, unless an unexpected pathogen is identified or considered likely and treated.

In summary, an essential diagnostic skill for every clinician is correctly identifying and distinguishing among HCAP, CAP, HAP, VAP, and aspiration pneumonia. Diagnosis is based on symptoms and physical examination and is then confirmed by chest X-ray. If the clinical findings strongly suggest pneumonia that requires treatment but the X-ray is negative, always document the clinical reasoning upon which the diagnosis is based.

If a specific causative pathogen is confirmed by culture or other diagnostic testing, that organism needs to be documented as the cause when it is identified. Otherwise, it is essential to document the probable, suspected, likely organisms causing HCAP, HAP, and VAP based on the solid clinical grounds of evidence-based literature, authoritative professional guidelines, and sound medical judgment. Recognition and documentation of aspiration pneumonia as a distinct entity is always important. The inability to specify the suspected organism in CAP will not impact severity of illness classification or impair correct coding.

Adherence to these clinical documentation principles will allow the submission of precise coded data to correctly reflect patients' severity of illness, which is crucial to quality of care reporting, outcome measurement, and reimbursement.