Background Psoriatic arthritis (PsA) is a chronic inflammatory disorder associated with several severe comorbidities such as cardiovascular diseases, diabetes, and depression. Tumour necrosis factor inhibitor (TNFi) therapy fails among half of patients with PsA treated in routine care.
Objectives The objective of this population-based cohort study was to investigate if the presence of comorbidities were associated with disease activity, treatment response and adherence to therapy in patients with PsA treated with their first TNFi.
Methods Data on patient characteristics, disease activity and treatment adherence was obtained from the DANBIO register. Information on comorbidities according to the Charlson Comorbidity Index (CCI) and psychiatric comorbidities was obtained through linkage with the Danish National Patient Register. We performed Kaplan-Meier plots and multivariate Cox proportional hazard regression analyses adjusted for sex, age, disease duration, DAS28-CRP, obesity, smoking, concurrent methotrexate treatment, calendar period, and diagnosis with depression and/or anxiety. Percentages of patients achieving relevant clinical responses were calculated.
Results We identified 1750 patients eligible for analyses. Patients with higher CCI scores had statistically significantly higher disease activity measures at baseline compared with patients without comorbidities (Table 1). Kaplan–Meier curves showed shorter adherence to treatment for patients with CCI ≥2 compared with patients with lower CCI scores (CCI =0: 2.6 years [2.2 to 2.9], CCI =1: 2.2 years [1.7 to 2.8], CCI ≥2: 1.3 years [1.0 to 1.6], p<0.001) (Figure). Also, for patients with depression and/or anxiety the adherence to treatment was shorter compared with patients without depression and/or anxiety (absence of depression and/or anxiety: 2.4 years [2.1 to 2.6], presence of depression and/or anxiety: 1.7 years [0.26 to 3.0], p<0.027). In the multivariate Cox regression analysis a CCI score ≥2 was associated with increased risk of TNFi treatment discontinuation compared with patients without comorbidities (HR 1.72, [95% CI 1.26 to 2.37], p=0.001). A statistically significantly smaller proportion of patients with a CCI score ≥2 achieved EULAR good response (CCI =0: 41%; CCI ≥2: 23%) and EULAR good-or-moderate response (CCI =0: 54%; CCI ≥2: 47%) at 6 months compared with patients without comorbidities.
Conclusions Presence of comorbidities was associated with higher baseline disease activity, increased risk of TNFi treatment discontinuation and reduced clinical response rates in a cohort of Danish patients with PsA.
Disclosure of Interest C. Ballegaard Speakers bureau: Janssen Pharmaceuticals, P. Højgaard Speakers bureau: Celgene, UCB, L. Dreyer Speakers bureau: UCB, MSD, Janssen, R. Cordtz: None declared, T. Jørgensen Speakers bureau: Abbvie, Roche, UCB, Novartis, M. Skougaard: None declared, S. Tarp Grant/research support from: Abbvie, Roche, Consultant for: MSD, L. Kristensen Speakers bureau: Pfizer, AbbVie, Amgen, UCB, Celgene, BMS, MSD, Novartis, Eli Lilly, Janssen Pharmaceuticals