Presentation: The Prevalence, Incidence, and Effect of Anti-Tumor Necrosis Factor (TNF) on Work Disability in Rheumatoid Arthritis (2007)

729 The Prevalence, Incidence, and Effect of Anti-Tumor Necrosis Factor (TNF) on Work Disability in Rheumatoid Arthritis

PURPOSE. Rheumatoid arthritis (RA) leads to work disability in many persons with the disorder. Work disability varies with severity of illness, but also with economic conditions and governmental social policies. Modern RA treatments that reduce disease activity, such as anti-tumor necrosis factor (TNF) therapy, might reduce the rate of work disability. In this study we determined the effect of anti-TNF therapy on work disability, as well as the prevalence and incidence of work disability in RA.
METHODS. We used a longitudinal data bank to evaluate work disability in 8,082 RA patients who were employed when RA was diagnosed. Patients were followed for up to 5.5 years as long as they were less than 62 years of age. Reported work disability and Social Security disability (SSD) incidence rates were determined in a subset (N = 4,155) of those employed at study onset. The effect of anti-TNF therapy on work disability was determined by conditional logistic regression, after adjustment for covariates that included demographic factors, comorbidity, and clinical variables that included HAQ, symptom intensity scale, count of prior DMARDS, corticosteroid use, RADAI joint score, VAS pain, total joint arthroplasty, NSAID and analgesic use.
RESULTS. At a median of 12.8 years after RA onset, 56.2% were still employed, 43.8% were not working, and 22.7% considered themselves disabled. In addition, 30.5% had stopped work over their lifetimes for health reasons and 20.6% were currently receiving SSD. The annualized incidence rate for self-reported work disability was 2.5% (95% CI 2.2%-2.8%) and for SSD was 1.9% (95% CI 1.7%-2.2%). The annualized incidence rate for persons who stopped working for any cause and did not resume employment was 4.0%. Almost all study variables were predictive of work disability. In multivariable analyses, college education had a strong protective effect, odds ratio (OR) 0.4, and smoking had strong negative effect, OR 1.9. Among clinical variables, treatment with corticosteroids and analgesics were predictive of work disability (OR 1.5), as was a 1 unit increase in HAQ score (OR 3.4), joint score (OR 1.04), and total joint arthroplasty (OR 2.9). Anti-TNF use was not associated with the risk of SSD, odds ratio 1.2 (95% CI 0.8 to 1.8), p = 0.441, but was associated with an increased risk of self-reported work disability, odds ratio 1.6 (95% CI 1.1 to 2.4, p=0.014, after adjustment for covariates.
CONCLUSIONS. Work disability occurs in 2.5% of RA patients annually, and SSD in 1.9%. Cross-sectional rates of self-reported disability are lower than noted in previous studies, perhaps reflecting overall improvement in RA therapy. We could not discern a protective effect of anti-TNF therapy on the risk of work disability. Possible reasons for this finding include insufficient efficacy of anti-TNF therapy, as well as the possibility that covariate control was incomplete.

  F. Wolfe, Centocor, Abbott, Bristol-Myers Squibb, Amgen, 2; S. Allaire, None; K. Michaud, None.