Obesity, Coronavirus, and Reporting  

The diagnosis of obesity is a risk factor for coronavirus.

Recently, the Centers for Disease Control and Prevention (CDC) updated information regarding the risk factors for COVID-19. Included in their high-risk groups are those with the following:

• Asthma
• Chronic kidney disease treated with hemodialysis
• Diabetes
• Hemoglobin disorders (e.g. sickle cell disease and thalassemia)
• Chronic lung conditions (e.g., COPD, Idiopathic pulmonary fibrosis, cystic fibrosis, emphysema, and chronic bronchitis)
• Immunocompromised (e.g., undergoing cancer treatment, status post organ transplant, and HIV status)
• Liver disease (such as cirrhosis)
• 65 years of age and older
• Residents of a nursing home or long-term care facility
• Serious heart conditions (e.g. congestive heart failure, cardiomyopathy, pulmonary hypertension, and congenital heart conditions)
• Severe obesity (body mass index greater than 40)

There has been discussion on many of the risk factors, as well as data showing deaths in the risk groups, such as deaths in the nursing home population. One interesting risk factor is severe obesity.

Obesity is defined as an excessive amount of body fat. Obesity increases a patient’s risk for heart disease, hypertension, and some specific cancers. Obesity is measured by body mass index (BMI). Body mass index is the weight in kilograms, divided by the square of height in meters for adults (age 20 and older). BMI is an indicator of body fat, not necessarily the health of the patient. The categories of obesity are:

• Underweight – BMI less than 18.5
• Normal – BMI is equal or greater than 18.5 and less than 25
• Overweight – BMI is equal or greater than 25 and less than 30
• Obesity, Class I – BMI is equal or greater than 30 and less than 35
• Obesity, Class II – BMI is equal or greater than 35 and less than 40
• Obesity, Class III (morbid or extreme obesity) – BMI is equal or greater than 40

BMI is measured differently for children. For pediatric patients, the measurement is based on age, gender, and percentiles.   

The coding for weight diagnoses can be found in various chapters of ICD-10-CM. Being underweight is coded as R63.6, which is in Chapter 18 (Signs, Symptoms, and Abnormal Clinical and Laboratory Findings, Not Elsewhere Classified). The code for obesity is found in Chapter 4 (Endocrine, Metabolic, and Nutritional Diseases). The code for morbid obesity is E66.01, which is also in Chapter 4. BMI can be used to define the extent of obesity. BMI can be found in Chapter 21 (Factors Influencing Health Status and Contact with Health Services) and Category Z68. Adult BMI is reported with codes Z68.0 – Z68.45. Pediatric BMI is reported with codes Z68.51-Z68.54. There is an instructional note with Category Z68 that the adult BMI applies to patients age 20 and older. Pediatric BMI is reported based on growth charts from the CDC and applies to ages 2-19. These BMIs are reported based on percentiles.

In addition to the coding guidance included in ICD-10-CM, there is additional guidance found in the Official Coding and Reporting Guidelines for ICD-10-CM. In Section I.B.14, there is guidance regarding BMI that can be documented by other clinicians than the patient’s provider. In Section I.C.21.c3, the coder is advised that BMI may not be coded without a reportable diagnosis, such as obesity. BMI should not be reported for pregnant patients.  

As you develop facility-specific guidelines, it is important to identify where BMI documentation can be located, and which documentation is the “source of truth.” BMIs can change during the patient’s visit, so the coder should be consistent in reporting BMI. Note that the Official Coding and Reporting Guidelines state that BMI should not be reported unless there is a reportable diagnosis. Did the provider address the patient’s weight? Does the diagnosis meet the definition of a reportable diagnosis? BMI of 19.9 or less and 40 and greater is considered a complication/comorbid condition in the Inpatient Prospective Payment System (IPPS) methodology. Payers are questioning the reporting of BMI when weight is not addressed during the patient’s stay. 

The diagnosis of obesity is a risk factor for coronavirus, but also a focus for payer review of claims. Ensure that weight and BMI are reported accurately.

 Programming Note: Laurie Johnson is a permanent panelist on Talk Ten Tuesdays. Listen her Coding Report live every Tuesday, 10-10:30 a.m. EST.