Background Biological therapies have greatly improved the management of psoriatic arthritis (PsA). Minimal disease activity (MDA) has become the optimal target in the treatment of PsA, waiting for a standardized definition of remission. Knowing the proportion of PsA patients in the MDA state could inform on the quality of management of these patients.
Objectives To determine the prevalence of MDA (Coates et al.) in patients with PsA in Spain as well as its potential predictors. To evaluate the association between MDA and the impact of disease, as evaluated by the PsA Impact of Disease questionnaire (PsAID).
Methods This was a non-interventional, cross-sectional, multicenter study, which aimed to evaluate the prevalence of MDA in a Spanish population with PsA. The study was carried out at 25 rheumatology outpatient clinics between May/2014 and Feb/2015. A total of 238 adult patients diagnosed with PsA (CASPAR criteria) with at least one year disease duration and treated with biological and non-biological DMARDS were included. Finally, 227 were considered evaluable. Clinical, demographic, treatment data, physical function (HAQ) and quality of life (PsAID) were obtained. According to the latter, the patient acceptable symptoms state (PASS) has been defined as a PsAID value <4. All patients gave informed consent. An Ethics committee board approved the final version of this study.
Results Overall, 133 out of 227 (58.6%) subjects achieved MDA at study entry. Seventy-seven (37.9%) and 137 (64.4%) patients reached joint and skin remission, respectively. However, a fair relationship between MDA and joint remission (k=0.390) and a slight relationship between MDA and skin remission (k=0.178) were observed. Patients in MDA state had better functional capacity by HAQ (0.35 ± 0.47) vs non-MDA patients (0.79 ± 0.63), p<0.001. These patients also had a significantly lower impact of the disease as measured by PsAID: MDA patients (3.34 ± 3.05) vs non-MDA patients (7.13 ± 5.21), p<0.001. In multivariate logistic regression analysis, male gender (OR 2.74, p=0.001), sedentary lifestyle (OR 3.13, p=0.002), familial history of PsA (OR 0.38, p=0.036), CRP level (OR 0.92, p=0.010) and use of corticoids (OR 0.33 p=0.007) were predictors of MDA. Painful entheses count ≤1 was the MDA criterion met by the highest proportion of patients (80.5%), whereas reaching a global disease activity VAS score ≤20 was achieved by only 43.2% of them.
Conclusions MDA was achieved by nearly 60% of patients in this study reflecting clinical practice in agreement with results from earlier studies. These patients had better functional state and most of them reached an acceptable symptoms state according to the PsAID. Our results of predictors to achive MDA should be confirmed in further prospective studies.
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Acknowledgement This work has been funded by Pfizer
Disclosure of Interest None declared