Flare status was assessed via physician review of aggregate data. Patients also completed the Rheumatoid Arthritis Flare Questionnaire (RA-FQ) each week up to six weeks postoperatively, as well as the RAPID-3 and the tender-painful joint region score modified from the Rheumatoid Arthritis Disease Activity Index questionnaire. “[Although] flare status did not require MD-patient concordance, discordance was minimal,” the researchers wrote.
Among the 120 patients in the analysis, 83% were female, 81% were white and 44% underwent total hip replacement.
Researchers found no any major differences in patients, disease characteristics or flare rates among those having total knee vs. total hip replacement. Disease flare occurred in 63% of patients, with a median time to flare after surgery of two weeks. The median severity of flares was 7 on a scale of 1–10, with a median duration of four to seven days. Twenty-two patients flared on the day of surgery (baseline), but there was no difference between those with baseline vs. post-baseline flare.
Flaring patients were more likely to be treated with biologics than with other agents (57% vs. 42%, P = 0.14). Researchers found no difference among flarers treated with biologics (51% for flarers vs. 53% for nonflarers) or glucocorticoid use on the day of surgery (88% for flarers vs. 86% for nonflarers).
Disease activity was higher at baseline for patients who flared; they also had higher DAS28-joint count, C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) and Clinical Disease Activity index, as well as RAPID-3. “Inflammatory markers such as CRP and ESR were higher at baseline in flarers, and the number of tender joints … and the number of swollen joints were significantly higher,” the researchers wrote.
At baseline and at six weeks, flarers had significantly worse MD-HAQ function, although the change from baseline to six weeks was similar between the flarer vs. nonflarer groups. Participants with flares noted they reduced the amount of activities they did, rested more and avoided activities they had planned to do. Seventeen percent increased analgesics or anti-inflammatories, and 5% increased glucocorticoids to manage flare. “Only 4% sought help from their rheumatologist,” the researchers wrote.
Patients who met both the 2010 and 1987 RA classification criteria had a greater than fivefold increase in flare risk (OR 5.89, P = 0.002). Flare risk also appeared higher in those with higher disease activity at baseline, and in patients with high disease activity by DAS28-ESR and elevated RAPID-3.
