Patients with rheumatoid arthritis (RA), particularly elderly patients, who receive the influenza vaccine have significantly lower morbidity and mortality, according to a study published in the June issue of the International Journal of Rheumatic Diseases

Chun-Ming Chen, of the Ditmanson Medical Foundation Chiayi Christian Hospital in Chiayi City, Taiwan, and colleagues conducted a retrospective population-based cohort study using data from the Taiwan National Health Insurance Research Database.

The Cox proportional hazards regression model was used to analyze the efficacy of influenza vaccination for 3,748 RA patients aged 18 years and older who were vaccinated in 2008, 2009, and 2010, and 3,748 matched RA patients who were not vaccinated.

The researchers, after adjusting for potential confounding factors, found that RA patients who received the influenza vaccine had reduced risk of hospitalization for septicemia, bacteremia, or viremia (hazard ratio, 0.65; 95 percent confidence interval, 0.45 to 0.94), and lower risk of mortality. The effectiveness of the influenza vaccination was particularly significant among elderly patients with RA.

Results

The influenza vaccination rate in RA patients was 14.8% in 2008, 19.8% in 2009 and 9.50% in 2010. Receiving influenza vaccine was associated with reduced risk of hospitalization for septicemia, bacteremia or viremia (hazards ratio [HR] = 0.65, 95% CI = 0.45–0.94), and lower risk of mortality (HR = 0.62, 95% CI = 0.39–0.97). The effectiveness was particularly significant in elderly patients.

"Receiving influenza vaccine by RA patients is associated with lower risk of hospitalization for septicemia/bacteremia/viremia and mortality," the authors write. "The risk reductions in the elderly RA patients were even greater."

RA patients receiving influenza vaccine have significantly lower morbidity and mortality, particularly in elderly patients. Further studies are needed to explore effective policies to increase the vaccination rate in elderly RA patients.