Abstract
The aim of the study was to assess the indirect costs, health-related quality of life and clinical characteristics of patients with psoriatic arthritis (PsA), measured using a PsA disease activity index in Poland. Additionally, we aimed to investigate the association between the activity, utility of PsA-affected patients and productivity loss in a Polish setting. A questionnaire survey was conducted to assess disease activity, as well as productivity loss, and a paper version of the EuroQoly-5D-3L questionnaire was used to assess productivity loss and the quality of life. Indirect costs were assessed with the human capital approach employing the gross domestic product (GDP) per capita, gross value added (GVA) and gross income (GI) per worker in 2014 in Poland and were expressed in Polish zlotys (PLN) as well as in euros. The correlation was presented using the Spearman correlation coefficient. Our analysis was performed on the basis of 50 full questionnaires collected. We observed a mean utility value of 0.6567. The mean number of days off work was 2.88 days per month, and mean on-the-job productivity loss was 24.1 %. Average monthly indirect costs per patient were €206.7 (864.01 PLN) calculated using the GDP; €484.56 (2025.46 PLN) calculated using the GVA; and €209.70 (876.56 PLN) calculated using the GI. PsA reduces the patients' quality of life as well as their productivity loss associated with both absenteeism and presenteeism. Total indirect costs were negatively correlated with utility. The greater the disease activity, the lower the utility and the greater the indirect costs.