OP0138-PC High Presence of Chronic Diseases at the Onset of Inflammatory Arthritis: Results from a Population-Based Study

Background Several cross- sectional studies report the prevalence of additional chronic diseases in patients with inflammatory arthritis (IA), but only in established disease.[1,2] Most studies include newly diagnosed IA patients without other chronic diseases, or limit their study population to just one specific additional chronic disease in patients with IA and consequently exclude patients with multi-morbidity.[3,4] Moreover, it is unclear whether comorbidity in IA patients is increased compared to what one might expect based on age and sex. Studies performed on IA patients in community based settings are scarce and a clear overview of the number and type of chronic diseases present at onset of IA is lacking. Objectives To determine the prevalence of chronic diseases at the onset of inflammatory arthritis (IA) in a community based setting and determine whether this is different from age and sex matched controls. Methods In this nested-case-control study, data was used from the Netherlands Information Network of General Practice (LINH). Diagnostic information, recorded according the international classification of Primary Care (ICPC), from electronic medical records from general practitioners were used. 3,354 patients with newly diagnosed IA were included. Each patient was matched on age, sex, and general practice with 2 control patients. In total, we compared the presence of 121 different chronic diseases between patients and controls with logistic regression analyses. Results Of the 3,354 patients and 6,708 controls, nearly two-third were female, and the mean age was 55 years (SD=15). 70% of the IA patients had at least one chronic disease at the onset of IA, whereas 59% of the control patients had at least one chronic disease at inclusion. The highest prevalence rates in IA patients were found for cardiovascular (2-22%) and musculoskeletal diseases (3-13%), followed by respiratory diseases (6-8%). Compared to the control patients, patients with IA had the highest increased risk for musculoskeletal diseases with an OR of 1.7 (95%CI: 1.6-1.9), for neurological diseases (OR; 1.6 [1.4-1.7]) and diseases of blood and blood forming organs (OR=1.6; [1.2-1.7]). Conclusions At the onset of IA, the vast majority of the patients have at least one other chronic disease. Because of the large impact of present chronic diseases on disease course of IA and possibly on treatment, these diseases should be taken into account when treating IA patients. References Michaud K et al Best Pract Res Clin Rheum 2007; van Tuyl LH et al ARD 2010; Daoussis D et al ARD 2010; Peters MJ et al J Rheum 2009 Disclosure of Interest None Declared