Development and validation of a risk score for serious infection in patients with rheumatoid arthritis

Abstract

Background Infection risk is increased in patients with rheumatoid arthritis (RA), and accurate assessment of infection risk could inform clinical decision-making. The purpose of this study was to develop and validate a score to predict the 1 year risk of serious infections. Methods We utilized a population based cohort of Olmsted County, Minnesota residents with incident RA ascertained in 1955–1994 that were followed longitudinally through their complete medical records until January 2000. The validation cohort included residents with incident RA ascertained in 1995–2007. The outcome measures included all serious infections (requiring hospitalization or intravenous antibiotics). Potential predictors were examined using multivariable Cox models. The risk score was estimated directly from the multivariable model and performance was assessed in the validation cohort using Harrell’s c-statistic. Results Among the 584 patients with RA (mean age 58 years; 72% female; median follow-up 9.9 years), 252 had ≥ 1 serious infection (646 total infections). The risk score included age, previous serious infection, corticosteroid use, elevated erythrocyte sedimentation rate, extraarticular manifestations of RA and comorbidities (coronary heart disease, heart failure, peripheral vascular disease, chronic lung disease, diabetes mellitus, alcoholism). Validation revealed good discrimination (c-statistic =0.80). Conclusion RA disease characteristics and comorbidities can be used to accurately assess the risk of serious infection in patients with RA. Knowledge of risk of serious infections in patients with RA can influence clinical decision making and inform strategies to reduce and prevent the occurrence of these infections.

Risk of infection with biologic antirheumatic therapies in patients with rheumatoid arthritis

“…Three such risk scores have been developed [13,105,106]. The first was from a retrospective cohort in Olmstead County over 40 years from 1955 to 1994 and subsequently validated in a more contemporary cohort; however, the study was underpowered to look at the incremental risk conferred by biologic therapy [106]. The second was from the US administrative insurance databases among 11,657 anti-TNF users [105] and the third by the German RABBIT investigators, all with very similar results [13,107].…”

Biological agents and respiratory infections: Causative mechanisms and practice management

“…It is a methodological challenge to estimate the contribution of each of these risk factors to the overall risk of infection in RA patients. Crowson et al [19] tried to accurately assess the risk of infection of individual RA patients by developing and validating a score to predict the one-year risk of serious infections. Their risk score encompasses age, comorbidities, measures of disease severity and disease activity, corticosteroid treatment, and previous infection [19].…”

“…Crowson et al [19] tried to accurately assess the risk of infection of individual RA patients by developing and validating a score to predict the one-year risk of serious infections. Their risk score encompasses age, comorbidities, measures of disease severity and disease activity, corticosteroid treatment, and previous infection [19]. Similarly, Strangfeld et al developed and validated a risk score for serious infections in patients with RA that contained the following risk factors: age, functional status, specific comorbidities (chronic renal or lung disease), treatment with corticosteroids, number of disease-modifying anti-rheumatic drug (DMARD) treatment failures, previous serious infection, and current TNF inhibitor or nonbiological DMARDs [20,21].…”

“…Doran et al [30] identified increasing age, presence of extra-articular manifestations of RA, and comorbidities as strong predictors of infection. Significantly increased risk of infections has been described for RA patients with chronic obstructive pulmonary disease and other chronic lung diseases [3,4,6,19,[31][32][33][34][35], chronic kidney Table 1 -Currently available biological agents in patients with immune-mediated inflammatory disease and the indications in Japan. r e s p i r a t o r y i n v e s t i g a t i o n 5 3 ( 2 0 1 5 ) 1 8 5 -2 0 0 diseases [18,34], and diabetes mellitus [34,35].…”

“…However, corticosteroids are potent immunosuppressive drugs, and their potential to increase patient susceptibility to major infections has been noted in patients with RA [18,30,35,[39][40][41][42][43] in a dose-dependent manner [18,19,37,44]. Methotrexate (MTX) is one of the most commonly used drugs in the treatment of RA.…”