Q&A: Avoid “rule out” to ensure medical necessity

Q: I know that in an inpatient setting coders are allowed to use a suspected diagnosis when a definitive diagnosis cannot be determined. However, we have had some trouble with physicians using the term “rule out” or “differential diagnosis” when it comes to a recovery audit contractor’s medical necessity scrutiny, because those terms are nonspecific. Do you have any guidance on how physicians should use those phrases or what phrases might be more beneficial from a medical necessity standpoint?

A: The phrase “rule out” means that the physician is attempting to discount a particular diagnosis from the list of possible or probable conditions the patient may have. He is attempting to “rule out” a particular scenario of treatment. Although ICD-9-CM Official Guidelines for Coding and Reporting (Section 1, B.6) states that “codes that describe symptoms and signs, as opposed to diagnoses, are acceptable for reporting purposes when a related definitive diagnosis has not been established by the provider,” doing so should be an exceptional situation where, despite numerous tests, no definitive diagnosis could be found.

From my perspective, if the physician writes “rule out” in the medical record, it should raise questions for the CDI specialist of what was really happening with the patient. It is the role of the CDI staff to speak to the suspected, possible, and questionable, to help determine what the physician was really thinking, and to get that clinical thought process into the patient’s medical record.

If the physician suspects a particular diagnosis, that’s what the medical record should indicate. Realistically, it makes more sense. If the physician is using X, Y, and Z antibiotics because he suspects the patient has gram-negative pneumonia, he should write that in the medical record rather than simply writing pneumonia and administering those drugs.

Certainly, if the physician suspects something and then changes his mind, the documentation should change to reflect the shift in his clinical opinion. From a decision-making perspective, if the physician suspects a particular diagnosis over other possibilities, why not write the suspected diagnosis rather than the five things on the list that the physician is going to “rule out?”

Editor’s Note: This question was answered by Fran Jurcak, RN, MSN, CCDS, in Chicago, during the HCPro audio conference “Clinical Documentation Improvement: Strengthen your program and protect against denials.” At the time of this article's original release, Jurcak was Director in the CDI practice of Huron Healthcare.