By now, I’m sure you’re knowledgeable about things like healthcare exchanges and other parts of the Accountable Care Act, the increasing number of metrics within hospital value-based purchasing, the physician value-based payment modifier, the physician quality reporting system (PQRS), how to use your hospital’s new EHR efficiently, the new “two-midnight rule” to determine inpatient vs. observation status, and so on.
You’re to be commended if you’re staying on top of all these things and have effective plans in place to ensure good performance on each. And if you haven’t already, you should add at least one more important issue to this list—the transition to ICD-10 coding on Oct. 1, 2014.
ICD stands for International Classification of Diseases, and the U.S. has been using the 9th revision (ICD-9) since 1978. ICD-9 is now significantly out of step with current medical knowledge and has run out of codes in some disease sections (“chapters”). This might mean, for example, that new codes for heart diseases would be assigned to the chapter for eye disease, because the former is full.
ICD-10 provides a way to fix these problems and, through more specific coding of diseases, should be able to yield more useful “big data” to measure things like safety and efficacy of care and more accurately identify diagnosis trends and epidemics. And, in theory, it could reduce the number of rejected billing claims, though I’m waiting to see if that happens. I worry that even after fixing all the initial bugs related to the ICD-10 transition, we will see more claim rejections than we experience today.
ICD codes can be thought of as diagnosis codes. CPT codes (Current Procedural Terminology) are an entirely separate set of codes that we use to report the work we do for the purposes of billing. We need to be familiar with both, but it is the ICD codes that are changing.
ICD-10 Basics and Trivia
The World Health Organization issued the ICD-10 in 1994, and it is already in use in many countries. Like some other countries, the U.S. made modifications to the WHO’s original code set, so we refer to ICD-10-CM (Clinical Modification), which contains diagnosis codes. The National Center for Health Statistics, a department of the CDC, is responsible for these modifications.
The WHO version of ICD-10 doesn’t have any procedure codes, so CMS developed ICD-10-PCS (Procedure Coding System) to report procedures, such as surgeries, done in U.S. hospitals. Most hospitalists won’t use these procedure codes often.
Table 1 (left) compares ICD-10-CM to ICD-9-CM. Most of the additional codes in the new version simply add information regarding whether the diagnosis is on the left or right of the body, acute or chronic, or an initial or subsequent visit for the condition. But the standard structure for each code had to be modified significantly to capture this additional information. Some highlights of the seven-character code structure are:
- Characters 1–3: category; first digit always a letter, second digit always a number, all other digits can be either; not case sensitive;
- Characters 4–6: etiology, anatomic site, severity, or other clinical detail; for example, 1=right, 2=left, 3-bilateral, and 0 or 9=unspecified; and
- Character 7: extension (i.e., A=initial encounter, D=subsequent encounter, S=sequelae).
- A placeholder “x” is used as needed to fill in empty characters to ensure that the seventh character stays in the seventh position. For example, T79.1xxA equates to “fat embolism, initial encounter.” (Note that the “dummy” characters could create problems for some IT systems.)