News: Majority of ICD-10 arthritis codes not used, study suggests

The Journal of the American Medical Association (JAMA) recently published a study demonstrating that, between 2015 through 2021, codes designed to specify inflammatory arthritis were often ignored and replaced with general “non-specific,” “unspecified,” or “other” arthritis codes.

According to JustCoding, the researchers gathered data from PearlDiver, an administrative claims database, on more than 5 million patients diagnosed with inflammatory arthritis during the study period. They then juxtaposed the coding under ICD-9—which did not contain as many specified arthritic conditions—with the same instances under ICD-10-CM and examined the instances in which the new coding, under ICD-10 specificities, would have been merited.

During the course of their investigation, the researchers found that of the top 20 most common inflammatory arthritic codes, “65% contained unspecified or other specified in the verbiage.”

According to JustCoding, the five most common ICD-10-CM codes for inflammatory arthritis noted in the study were:

• M06.9 (rheumatoid arthritis, unspecified) was reported with 53.1% frequency
• M06.4 (inflammatory polyarthropathy) was reported with 15.6% frequency
• M05.79 (rheumatoid arthritis with rheumatoid factor of multiple sites without organ or systems involvement) was reported with 7.1% frequency
• M06.09 (rheumatoid arthritis without rheumatoid factor, multiple sites) was reported with 4.4% frequency
• M05.9 (rheumatoid arthritis with rheumatoid factor, unspecified) was reported with 3.3% frequency

The researchers suggested that the data implies the opportunity for improving future applications of specified ICD-10 codes and the specific documentation of conditions like inflammatory arthritis—a practice that “will be important in years to come if the benefits of ICD expansion are to be realized.”

Editor’s note: To read the JAMA study, click here. To read the JustCoding coverage, click here.