Back/joint Pain, Illness Perceptions and Coping are Important Predictors of Quality of Life and Work Productivity in Patients with Inflammatory Bowel Disease: a 12-month Longitudinal Study

Background and aims: Back and joint pain are the most common extraintestinal symptoms reported by patients with inflammatory bowel disease (IBD). We assessed the impact of back/joint pain, illness perceptions, and coping on quality of life (QOL) and work productivity in patients with IBD. Methods: Our cohort included 155 IBD patients with and 100 without arthropathy. Arthropathy was defined as daily back pain for >= 3 months and/or peripheral joint pain and/or joint swelling over the last year. At baseline and at 12 months, patients completed questionnaires on the extent of back/joint pain, IBD disease activity, illness perceptions, coping, QOL, and work productivity. The impact of back/joint pain, illness perceptions and coping on QOL and work productivity was determined, using linear mixed models. Results: In total, 204 IBD patients (72% Crohn's disease, 40% male, mean age 44 +/- 14 years) completed questionnaires at both time points. At both time points, IBD patients with back/joint pain reported a significantly lower QOL and work productivity compared with IBD patients without back/joint pain. Predictors of low QOL were back/joint pain (beta = -1.04, 95% confidence interval [CI] -1.40, -0.68), stronger beliefs about the illness consequences (beta = -0.39, 95% CI -0.59, -0.18) and emotional impact of IBD (beta = -0.47, 95% CI -0.66, -0.28), and the coping strategy 'decreasing activity' (beta = -0.26, 95% CI -0.48, -0.03). Predictors of work productivity were back/joint pain (beta = 0.22, 95% CI 0.07, 0.37) and illness consequences (beta = 0.14, 95% CI 0.06, 0.22). Conclusion: Back/joint pain, illness perceptions, and coping are significant predictors of QOL and work productivity, after controlling for disease activity.