Lumping and Splitting
Lumping and splitting coexist in a dynamic tension that is integral to progress. Whereas inflammatory arthritis was once lumped into two categories- rheumatoid arthritis and rheumatoid variants- now, many different forms of arthritis are distinguished to help predict outcome and guide treatment. Rheumatoid arthritis (RA) has been split into seropositive and seronegative versions whereas the rheumatoid variants have been set apart as psoriatic arthritis (PsA) and the spondyloarthropathies (SpAs) among others. Psoriatic arthritis now has at least 5 different forms while the SpAs have recently been divided into radiographic and non-radiographic versions.
While the splitting may make sense in the study of disease etiology, lumping may be preferable for the development of new therapy. Thus, the TNF blockers show impressive efficacy for almost all forms of inflammatory arthritis, including RA, PsA and SpA, despite any differences in the mechanisms promoting joint inflammation and destruction. Similarly, the glucocorticoids have benefits in the treatment of disease throughout all of medicine. Analgesics also have efficacy that transcends any disease classification.
In the area of coding, however, splitting appears to be in ascendency as the new International Classification of Diseases and Related Health Problems (ICD-10) system from the World Health Organization has dramatically expanded the list of diagnoses. The number of codes in the United States Clinical Modification of the ICD-10 totals 68,000. Indeed, there are separate codes for RA of the right wrist and RA of the left wrist and these can be subdivided on the basis of involvement of other organ systems. Since the codes will be used for billing, these differences now matter in terms of reimbursement and resource allocation.
Just as there are lumpers and splitters when it comes to medical diagnoses, there are lumpers and splitters when it comes to medical organizations. Orthopedics, for example, has separate societies for surgeons of the hand and wrist, shoulder and elbow, and foot and ankle to go along with the larger more inclusive societies. On the other hand, rheumatology has only a single professional organization perhaps because, by our nature, we like to take a broad view of musculoskeletal disease and try to be big tent people.
Among lumping organizations, the United States Bone and Initiative (USBJI) occupies a key role in the field. An organization of organizations, the USBJI includes patient and professional societies as well as a broad range of other stakeholders. While the word lump tends to have a negative connotation (e.g., a shapeless lump is not very attractive), the activities of the USBJI clearly indicate, lumping can be very positive. Lumping combines, joins and amalgamates. Lumping brings together people and groups by seeing the commonalities as opposed to the differences, forging new bonds and acquiring strength through shared goals.
For patients with musculoskeletal disease, the goals of care tend to be the same and focus on a few main issues: less pain, more mobility, less disability. Despite any differences in pathophysiology, etiology or the ICD-10 codes of their conditions, patients with musculoskeletal conditions benefit greatly from an organization that lumps their problems together to increase awareness, promote research and advocate for high quality care with a unified voice.
The USBJI is a new organization and is evolving to meet the ever changing landscape of modern medicine. By lumping rather than splitting, the USBJI can play a critical role in improving health care in the future however many different conditions its members treat and however many codes the ICD 10 system designates. In a new take on an old phrase, in this case, lump it and like it may be a very good way to go.