Abstract
Objectives The coexistence of multiple immune-mediated diseases (IMIDs) presents substantial challenges in healthcare management. This study investigates the timing of onset for psoriatic disease (PsD) and inflammatory bowel disease (IBD) and assesses how the sequence of diagnosis impacts mortality and hospitalization costs in patients with these concurrent conditions.
Methods We conducted a retrospective analysis using data from the Newfoundland and Labrador Centre for Health Information (NLCHI) spanning 2009 to 2019. Patients diagnosed with PsD were identified using the ICD-9 code 696 and matched with 75,500 controls without PsD. From this cohort of approximately 100,000 patients, individuals with IBD were identified using ICD-9 codes 555 for Crohn’s disease (CD) and 556 for ulcerative colitis (UC). The study recorded the sequence of IMID occurrences, mortality rates, and total hospitalization costs.
Results The analysis identified 15,100 patients with PsD and 2,800 with IBD. Among these, 14,368 had only PsD, 2,068 had only IBD, and 732 had both conditions, indicating that 4.8% of PsD patients also had IBD, including 525 with CD and 207 with UC. Notably, 65% of patients with both PsD and IBD were diagnosed with IBD first (Figure 1). This trend was consistent for both CD and UC, where 65% of patients developed CD or UC prior to PsD. For those diagnosed with PsD first, CD appeared an average of 7.58 years later, while PsD developed 9.76 years later when CD was diagnosed first (p = 0.004). In the case of UC, it followed PsD by 6.88 years, whereas PsD followed UC by 7.41 years (p = 0.13). The average age at death for patients diagnosed with CD before PsD was 67.6 years, compared to 70.7 years for those diagnosed with PsD first (p = 0.06). For patients diagnosed with UC before PsD, the average age at death was 66.5 years, compared to 78.3 years for those diagnosed with PsD first (p = 0.0001). No significant differences in total hospitalization costs were observed among the groups.
Conclusion The sequence of diagnosis in patients with multiple IMIDs significantly influences the timing of the onset of the second disease and may have implications for mortality. These findings highlight the necessity for effective management strategies for patients with concurrent IMIDs and underscore the potential impact of the order of diagnosis on patient outcomes.
- Copyright © 2026 by the Journal of Rheumatology
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