RA Patients More Likely to Have Functional Disability

Functional disability (FD) is significantly more common in patients with rheumatoid arthritis (RA) compared to the general population, a recent study found.

According to the study authors, writing in the June issue of Mayo Clinic Proceedings, RA is one of the top conditions most frequently associated with FD. “However, it remains unclear whether the excess of FD in RA is universal for all age groups, how serologic status impacts FD, and how trends of FD in RA compare with the general population.”

For the study, researchers evaluated data on RA patients aged 18 years and older from a single county in Minnesota between Jan. 1, 1999, and Dec. 31, 2013. Eligibility was based on fulfillment of the 1987 American Rheumatism Association criteria for RA, which was determined by querying the Rochester Epidemiology Project, which provided complete community-wide medical records. Disease incidence date was the earliest date the patient fulfilled at least four of the previously established RA criteria. A control group was created with other community residents without RA; controls were matched to RA patients based on age, sex, and calendar year of index date (corresponding to the RA patient’s incidence date). Additional data collected including smoking (never, current, or former) and obesity status, and for patients with an index year of 2005 or later, use of antidepressants within one year prior to the index date.

Patients self-reported activities of daily living (ADL) during routine Mayo Clinic visits; they were asked about their ability to perform the following tasks without assistance: feeding oneself, dressing, using the toilet, bathing, walking, and housekeeping. Patients who had difficulty with one or more of the six ADL were considered to have FD.

RA Patients More Likely to Struggle with ADL

Final analysis included 586 RA patients and 531 controls; each group filled out 4,301 and 3,145 questionnaires, respectively, for a total of 7,446 total completed questionnaires. Mean age at index date was similar between the RA (55.4 years) and non-RA (56.2 years) cohorts, and both groups were 70% female. Antidepressant use within the year leading up to the index date was also similar (28% versus 26%, respectively).

FD—defined as difficulty with at least one ADL—was significantly more prevalent in the RA group compared to the non-RA group at the RA incidence/index date (26% vs. 11%, respectively; P < 0.001). RA patients were also more likely to have difficulty with two or more ADL (13% vs. 5%, respectively; P < 0.001).

Notably, RA patients were significantly more likely to face challenges with ADL up to two years before their disease diagnosis; the study authors reported: “In the period from 3 to 2 years before RA incidence/index date, there was no statistically significant difference between cohorts (OR, 1.50; 95% CI, 0.74-3.05; P=.26). However, in the periods from 2 years to 1 year before and within 1 year before RA incidence/index date, patients with RA had a significantly higher prevalence of FD than the non-RA group (OR, 2.07; 95% CI, 1.66-3.64; P=.014 and OR, 2.78; 95% CI, 1.63-4.72; P<.001, respectively).”

Women had higher FD rates than men in both the RA (P < 0.001) and non-RA (P = 0.04) cohorts.

The researchers concluded by saying that their findings “[suggest] that additional vigilance may be needed to help improve their functional outcomes.”