Potential Impact of the ICD-10 Underdosing Classification System

By Kathleen E. Wall, MS, RHIA

The implementation of the ICD-10 classification system has provided an opportunity to capture data that has not been previously captured. The classification of “underdosing of drugs” can provide valuable information regarding not only the fact that a drug was underdosed, but also why. Think about the ramifications with readmission rates this one piece of data could potentially have. To this point, coding professionals have not been looking for documentation of this condition in the record so may require additional education related to the importance of coding underdosing of medications.

The Centers for Medicare and Medicaid Services (CMS) currently tracks readmission rates for chronic conditions such as heart failure, acute myocardial infarctions, pneumonia (including aspiration pneumonia), chronic obstructive pulmonary disease, coronary artery bypass (with certain conditions), and elective total hip and knee arthroplasty. Psychiatric conditions are not yet tracked but are the cause of many readmissions for patients who are noncompliant with medications.

The classification includes both the specific drugs underutilized (T36-T50 with the sixth character of “6”) as well as the reason why a patient didn’t take a drug correctly or at all (Z91.12X and Z91.13X). These two elements could have a huge impact on CMS data collection, hospital resource utilization, and the potential future reimbursement.

The code Z91.12X identifies “intentional” underdosing due to financial or other reasons and Z91.13X identifies “unintentional” underdosing due to age-related debility or other reasons. If we are able to consistently capture and report these data elements, we can analyze and predict or anticipate probable readmission rates in specific chronic conditions and begin to mitigate readmissions either through enhanced case management or social work intervention, patient education, and/or financial assistance for patients without monetary means to obtain drugs on a consistent basis. For those patients with “age-related” debilities (forget to take drugs or are inconsistent), education and assistance for care givers, home healthcare, or sitters may be required in order to ensure meds are taken correctly, thus helping to reduce potential readmissions.

Documentation of underdosing may require some additional effort. Providers typically document this type of information in the history of present illness section of the history and physical examination or the emergency room department documentation. Obtaining a complete history of home medications and the frequency of use is essential in determining if a patient is taking the drug as prescribed. The documentation of “noncompliance” with medications alone isn’t enough to capture these important data elements; the provider must indicate the patient is noncompliant by not taking prescribed drugs. Examples of terminology we see may be “the patient lost their insurance so is unable to afford drugs” or “patient stopped diuretics because he said they made him visit the restroom too much” or “patient ran out of drugs two weeks ago and hasn’t been out to buy more” or “patient lost his meds but couldn’t afford to refill” or “patient said drug made him feel fuzzy so he stopped taking them three weeks ago.” This documentation provides sufficient information for classifying underdosing and the reasons why the patient has stopped or decreased dosage.

CMS could also use this data for remodeling the readmission capture rates for these conditions and provide hospitals with incentives for programs put in place to reduce readmission rates. While not all aspects of patient care is 100 percent in the physician’s or hospital’s hands (patients do have responsibility for compliance), the monitoring of the outcomes of patient care (in this case, readmissions) falls on the shoulder of the hospital and the capture of these key elements may help in analyzing and understanding why they are occurring, as well as identify potential ways to mitigate them.

We have been given a gift with ICD-10-CM to be able to capture these very important key elements of patient care and the expected outcomes. Let’s use them to our advantage!

Kathleen E. Wall is an AHIMA-approved ICD-10-CM/PCS trainer and member of AHIMA’s Informatics and Data Analytics Task Force. She is ICD-10 project manager at himagine solutions.