This is our last post in a series of posts on the topic of ‘Data Standards in Health Informatics’. In this post we will go over 'Current Procedural Terminology (CPT®)' and 'Logical Observation Identifiers Names and Codes (LOINC®)' data standards in detail. Before you read this article further, we highly recommend you read Part I, Part II and Part III of this series. At a high level, CPT deals with medical procedures and services data, and it is used for treatment tracking and billing; whereas LOINC deals with lab orders & results data, and it is used for transmitting lab test observations.
Let’s dive into details…
Current Procedural Terminology (CPT®)
Current Procedural Terminology (CPT) is a classification of medical procedures maintained and updated annually by the American Medical Association (AMA). Like ICD, it is required for almost all reimbursement for health care services in the US.
With ICD, CPT is one of the most important code sets for medical coders to become familiar with. CPT codes are used to describe tests, surgeries, evaluations, and any other medical procedure performed by a healthcare provider on a patient. This code set is extremely large and includes the codes for thousands of medical procedures.
CPT codes are an integral part of the billing process. CPT codes tell the insurance payer what procedures the healthcare provider would like to be reimbursed for. As such, CPT codes work in tandem with ICD codes to create a full picture of the medical process for the payer. "This patient arrived with these symptoms (as represented by the ICD code) and we performed these procedures (represented by the CPT code)".
Like ICD codes, CPT codes are also used to track important health data and measure performance and efficiency. Government agencies can use CPT codes to track the prevalence and value of certain procedures, and hospitals may use CPT codes to evaluate the efficiency and abilities of individuals or divisions within their facility.
CPT codes are divided into three categories:
Category I codes are five-digit numbers for widely performed procedures and are divided into sections for anesthesiology, surgery, radiology, pathology/laboratory, and medicine.
Here’s a quick look at the sections of Category I CPT codes, as arranged by their numerical range.
Within each of these code fields, there are subfields that correspond to how that topic—say, Anesthesia,—applies to a particular field of healthcare. For instance, the Surgery section, which is the largest, is organized by what part of the human body the surgery would be performed on. Each of these fields has its own particular guidelines when it comes to use. For example, the Surgery section has a guideline for how to report extra materials used (such as sterile trays or drugs) and how to report follow-up care in the case of surgical procedures.
Category II codes are for the collection of quality and performance metrics and are four digits followed by an “F”. Here's a quick example: if a doctor records a patient's Body Mass Index (BMI) during a routine checkup, we could use Category II code 3008F, "Body Mass Index (BMI), documented." These codes never replace Category I or Category III codes, and instead simply provide extra information. They are divided into numerical fields, each of which corresponds with a certain element of patient care. Here is a list of these fields:
Category III codes are also four digits, followed by an “I”, and are temporary, to allow for new or experimental procedures . These represent emergent or experimental services, technology, and procedures. In certain cases, you may find that a newer procedure does not have a Category I code. There are codes in Category I for unlisted procedures, but if the procedure, technology, or service is listed in Category III, you are required to use the Category III code.
Category III codes allow for more specificity in coding, and they also help health facilities and government agencies track the efficacy of new, emergent medical techniques.
Logical Observation Identifiers Names and Codes (LOINC®)
Logical Observation Identifiers Names and Codes (LOINC®) is a clinical terminology that is important for laboratory test orders and results and is one of a suite of designated standards for use in U.S. Federal Government systems for the electronic exchange of clinical health information.
In 1999, LOINC was identified by the HL7 Standards Development Organization as a preferred code set for laboratory test names in transactions between health care facilities, laboratories, laboratory testing devices and public health authorities. In the future, LOINC is likely to become a HIPAA standard for certain segments of the Claims Attachment transaction.
Starting in 1994, health informatics pioneer, Dr. Clement “Clem” J. McDonald, organized the LOINC Committee to develop a common terminology for laboratory and clinical observations because of the growth of electronic messaging to send laboratory orders and test results which are often identified using a health system’s internal and typically unique code values. As a result, a receiving care system cannot fully “understand” and properly file the results they receive without considerable effort.
Each code is a number with up to seven digits. While the codes themselves are deceptively simple, their name contains important details in its five or six components. A fully specified LOINC name for a laboratory test indicates the component/analyte, the property analyzed or measured, the time over which this observation or measurement took place, the type of sample, the scale of the result and the method used to obtain it. These components, or parts, are separated by colons.
In the example shown above (Courtesy LOINC and The Regenstrief Institute) the first part—the component or analyte, the substance of interest—is Alpha 1 Globulin, a protein that is a marker for inflammation. The sixth part identifies the method used to determine the level as electrophoresis. The fourth or specimen part indicates that the test was performed on a blood serum or plasma sample. Test results with a unit of measure of mass in the numerator and a volume (like mg/dl) in the denominator have mass concentration (MCnc), as you see in the fifth part. Finally, Pt in the third part indicates that the measurement represents a point in time.