EDITOR’S NOTE: This article has been written in recognition that May was National Cystic Fibrosis Awareness Month. 

More than 33,000 people in the United States are affected with cystic fibrosis, with 1,000 new cases of the genetic disease diagnosed each year, according to the Cystic Fibrosis Foundation.

Surprisingly, at least half of the cystic fibrosis patients are over the age of 18. These patients suffer from frequent lung infections and over time the disease limits their ability to breathe.

A cystic fibrosis patient could have the following symptoms: very salty-tasting skin; persistent cough with occasional phlegm, wheezing, or shortness of breath; poor growth or weight gain; frequent oily, bulky stools; difficulty with bowel movements; or (in males) infertility. Thick mucus can build up in the liver and block the bile duct, impacting the absorption of nutrients and eventually leading to malnutrition.

The condition is congenital, as the fetus receives the defective gene from both parents. In the 1950s, life expectancy for those with cystic fibrosis was limited to elementary school, while today’s current advancements have enabled patients to live much longer with full lives.

Cystic fibrosis is coded by using “Fibrosis, cystic” in the Index with the default code of E84.9. The diagnosis has a non-essential modifier “of pancreas.” Notice the condition is found in Chapter 4 (Endocrine), not Chapter 10 (Respiratory). The Index provides further specificity for associated complications, such as distal intestinal obstruction syndrome (E84.19), fecal impaction (E89.19), intestinal manifestations NEC (E89.19), respiratory manifestations (E84.0), and other manifestations (E84.8). The Index entry appears to miss the manifestation of meconium ileus, which is coded with E84.11. The respiratory manifestations have a coding instruction to use additional code to identify any infectious organism present. 

Coding Clinic, Fourth Quarter 2002, pages 45–46, provides sequencing guidance with regards to cystic fibrosis and pulmonary manifestations. The guidance states in accordance with Uniform Hospital Discharge Data Set (UHDDS) guidelines that frequently the specific manifestation (such as Pseudomonas pneumonia (J15.1)) would be sequenced as the principal diagnosis as it is the reason that necessitated the patient’s admission to the hospital. If the attending physician determines cystic fibrosis is the reason for the admission, then it may be listed as the principal diagnosis. In short, the circumstances of the admission will determine the principal diagnosis.

Since the circumstances of admission determine the principal diagnosis, the Medicare Severity Diagnosis Related Group can vary. In looking at medical scenarios, the MS-DRG can vary significantly. If the patient has Pseudomonas pneumonia with cystic fibrosis, the resulting MS-DRG is 177 (Relative weight 1.9033). If the respiratory manifestation is atelectasis, the assigned MS-DRG is 205 (Relative weight 1.4478). If the physician determines that unspecified cystic fibrosis is the reason for admission, then the MS-DRG is 164 (Relative weight 0.7221). If the patient has cystic fibrosis with fecal impaction, the MS-DRG is 395 (Relative weight 0.6756), and note that the Tabular does not have instructions to also code the fecal impaction with the cystic fibrosis.

If a major complication or comorbid condition is documented, the MS-DRG can be optimized to 393 with a relative weight of 1.6335. In looking at one surgical scenario, a patient has cholecystitis due to cystic fibrosis which results in a laparoscopic cholecystectomy. The case will group to MS-DRG 418 and relative weight 1.6584. The cystic fibrosis will affect the MS-DRG assignment as it qualifies as a complication/comorbid condition. The clinical documentation will be very important in assigning the appropriate MS-DRG. 

Cystic fibrosis is a complicated disease that impacts patients early in life. It appears to be a complicated disease to code accurately as well. The coder will heavily rely on the clinical documentation for sequencing and specificity.

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