Chicago, IL—The number of total hip replacement (THR) and total knee replacement (TKR) surgeries has declined among patients with a primary diagnosis of rheumatoid arthritis (RA) since the introduction of biologic agents.
“This consistent and significant finding suggests that the availability of biologic agents, as well as other changes in the therapeutic approach to RA, may confer long-term benefits to both RA patients and healthcare systems,” concluded Neeta Tandon of Janssen Scientific Affairs, LLC, Horsham, PA, on a retrospective analysis of a large database of hospital inpatient stays, presented at the 2011 meeting of the American College of Rheumatology.
The researchers analyzed patient hospital discharge data between 1993 and 2008 using the Nationwide Inpatient Sample (NIS) of the Healthcare Cost and Utilization Project. The NIS contains discharge data from more than 1000 US hospitals from 1988 to 2009, allowing analysis of trends over time.
To capture the trends for THR and TKR, data were compared between patients with RA before and after the introduction of infliximab (Remicade) in 1999, adalimumab (Humira) in 2002, and etanercept (Enbrel) in 1998, and to patients without a diagnosis of RA.
A coding algorithm was used to identify the 1.7 million patients having THR or TKR procedures, 58,036 of whom had a diagnosis of RA.
The number of annual THR surgeries more than doubled between 1993 and 2008—from 25,987 to 56,478—whereas, the number of annual TKR procedures more than tripled—from 38,136 to 125,881—during this period.
The number of THR and TKR surgeries increased for patients with RA as a secondary diagnosis and for patients with no indication of RA. During the same time, the number of THR and TKR procedures for patients with a primary diagnosis of RA was decreasing.
Patients with RA as a primary or a secondary diagnosis had a significant 28% decrease (P <.01) in the likelihood of RA being the primary reason for undergoing THR or a TKR procedure after the time that biologic agents were introduced.—WK