Upper Limb Joint Replacements Decreasing Among Patients With RA
The incidence rate of upper limb joint replacements has decreased since 2002 among patients with rheumatoid arthritis.
For patients with rheumatoid arthritis (RA), the incidence rate (IR) of upper limb joint replacements has been decreasing since 2002, coinciding with the introduction of biologic disease-modifying antirheumatic drugs (bDMARDs), according to results published in Arthritis Research & Care.
The study included participants with incident RA from the Danish National Patient Register from 1996 to 2012 (n=18,654). Participants were matched by age, sex, and municipality with up to 10 general population controls.
The researchers calculated 5-year IRs using a composite outcome of any first joint replacement of the finger, wrist, elbow, or shoulder per 1000 person-years. They also used an interrupted time series analysis to determine trends and changes of the IR in the pre-bDMARD era (1996 to 2001) and the bDMARD era (2003 to 2012) with a 1-year lag period in 2002.
Within the first 5 years from the index date, 1.0% (n=193) of participants with RA had upper limb joint replacements.
From 1996 to 2001, the IR for joint replacements for participants with RA remained stable at 2.46 per 1000 person-years (95% CI, 1.96-2.96). From 2003 onward, the results indicated that the IR among participants with RA decreased -0.08 per 1000 person-years annually.
Among controls, the IR of joint replacements was 0.14 per 1000 person-years (95% CI, 0.07-0.21) in 1996. Unlike participants with RA, the IR for controls increased annually by 7% from 1996 to 2002. In 2003, the IR was 0.37 with annual increases that matched those of the earlier era.
“We found that the -year IR of upper limb joint replacements among newly diagnosed [patients with RA] started to decrease following the introduction of bDMARDs,” the researchers wrote. “However, given the ecological design of the study, it is a possibility that other factors contributed to this finding.”
Cordtz R, Hawley S, Prieto-Alhambra D, et al. Reduction in upper limb joint surgery among rheumatoid arthritis patients: an interrupted time series analysis using Danish health care registers [published online January 25, 2019]. Arthritis Care Res (Hoboken). doi:10.1002/acr.23835