What’s the Skinny on Obesity and BMI Coding??
Overweight and obesity are increasingly common conditions in the U.S. They are caused by the increase in the size and amount of fat cells in the body. Doctors measure body mass index (BMI) and waist circumference to screen and diagnose overweight and obesity. The National Institute of Health has deemed obesity as a serious medical condition that can cause complications such as metabolic syndrome, high blood pressure, atherosclerosis, heart disease, diabetes, high blood cholesterol, cancers, and sleep disorders. The Center for Disease Control states BMI and waist circumference are two measures that are used as screening tools to estimate weight status in relation to potential disease risk.
As coders, we all know the importance of clear and concise documentation in the clinical record. When the physician has documented obesity, or any severely abnormal weight-related diagnosis (e.g., morbid obesity, malnutrition, etc.), this meets the UHDDS definition of a co-existing condition and should be coded. But what about BMI?
AHA’s Coding Clinic, Second Quarter, 2010, states that a dietician can report and document a patient’s BMI. However, it still should not be coded unless the provider has noted it within the outpatient or inpatient record, along with its medical significance.
This caused some confusion; what if the patient was not seen by a dietician? What documentation was required to show the medical significance of the BMI? The 2017 ICD-10-CM Official Coding Guidelines clarified further:
Documentation for BMI… New addition where the documentation may get through non-physicians.
“For the body mass index (BMI)…code assignment may be based on medical record documentation from clinicians who are not the patient’s provider (i.e., physician or other qualified healthcare practitioner legally accountable for establishing the patient’s diagnosis), since this information is typically documented by other clinicians involved in the care of the patient (e.g., a dietitian often documents the BMI…). However, the associated diagnosis (such as overweight, obesity, acute stroke…) must be documented by the patient’s provider. If there is conflicting medical record documentation, either from the same clinician or different clinicians, the patient’s attending provider should be queried for clarification. The BMI…codes should only be reported as secondary diagnoses.”
When coding overweight/obesity in ICD-10, we are referred to the E66.- category; here we see an instructional note under this category that states: Use additional code to identify body mass index (BMI), if known (Z68.-)
If a patient’s BMI is noted within the medical chart by a dietician or nurse, and the physician has documented the associated weight-related condition, coders should code the BMI.
In the hospital setting, coding and documenting the levels of obesity/morbid obesity can trigger a Hierarchical Condition Category (HCC). An HCC has increased payment considerations for the facility, which may be appropriate for an obese or morbidly obese patient. The care of an obese or morbidly obese patient may require extra work and cost to treat, in coordination with other acute or chronic conditions being treated at that time.
As coders, we need to encourage our physicians and providers to document this important medical information as part of the physical exam findings when treating common conditions such as:
◾Dyslipidemia (for example, high LDL cholesterol, low HDL cholesterol, or high levels of triglycerides)
◾Diabetes (both Type 1 and Type 2)
◾Coronary heart disease and Stroke
◾Sleep apnea and respiratory problems
◾Some cancers (endometrial, breast, and colon)
◾Pregnancy and fetal anomaly