Background Several chronic diseases such as cardiovascular diseases, pulmonary diseases, and gastrointestinal diseases are known to be increased in inflammatory arthritis (IA) patients.[1-3] Longitudinal studies in community-based settings about the development of comorbid disorders in patients with IA are scarce. Most available studies addressing IA patients focus either on one single comorbid disorder or one group of diseases, but refrain to study the risk of a broad range of possible new comorbidities, while this information could be helpful in optimising primary or secondary preventive care in IA patients. Moreover, often a suitable control group is lacking to compare incidence rates in IA patients with rates one might expect based on age and sex.
Objectives To ascertain the risk of newly developed chronic comorbid disorders in patients with IA in a community-based setting compared to matched control patients.
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, from electronic medical records from general practitioners was used. 3,354 patients with newly diagnosed IA were included. Each patient was matched on age, sex, and general practice with 2 control patients. The development of 121 chronic comorbid disorders was compared between groups using Cox regression.
Results Of the 3,354 patients and 6,708 controls, nearly two-third were female, and the mean age was 55 years (SD=15). After a median follow-up duration of 2.8 years, 56% of the IA patients developed at least one chronic comorbid disorder after the onset of IA compared to 46% of the controls (p<0.05). 33% of the IA patients had no other chronic disorder at inclusion compared with 48% of the controls. Of the IA patients without comorbidity, 41% developed one or more chronic diseases during follow-up, compared with 37% in the control group (p<0.001). Of the IA patients with one or more chronic comorbid disorder at the onset of IA, 59% developed one or more additional chronic comorbidities during follow-up, compared with 51% in the control group (p<0.001). The most common comorbid disorders after IA diagnosis were from cardiovascular (50%), musculoskeletal (40%) and neurological origin (33%). The highest, statistically significant, hazard rates (HRs) in IA patients were found for anaemia, osteoporosis and COPD (HR=1.8 (95% CI 1.4-2.7), HR=1.9 (95% CI 1.5-2.5) and HR=1.8 (95% CI1.4-2.3 ), respectively).
Conclusions Patients with IA develop more chronic comorbid disorders after the onset of IA than one might expect based on age and gender. Since comorbidity has a large impact on the disease course, quality of life, and possibly on treatment itself, prevention of comorbidity should be one of the main targets in the treatment of IA patients. This should obtain more attention in daily care of IA patients.
Michaud K and Wolfe F, BPRCR 2007;
Mikuls TR, BPRCR 2003;
Gabriel SE and Michaud K, ART 2009
Disclosure of Interest None Declared