OBJECTIVES: To evaluate the relationship between the disease activity measures (HAQ, PASI) and patient’s QoL based on different utility mappings and its influence on cost-effectiveness (CE) METHODS: The identified algorithms of a literature research project that includes database screening of publications in English language from 1996-2015 have been extracted and the differences have been explored in a CE model for PsA. The model follows a decision tree for the first 12 weeks and Markov structure for rest of the time horizon with three month cycle length. RESULTS: The research retrieved 13 different algorithms to derive utilities in PsA patients based on clinical study data. In these studies, utilities were measured either with the SF-36 (n=5) or the EQ-5D (n=9) instruments. Different algorithms used different independent variables such as HAQ-DI, PASI or Disease Activity Score 28 (DAS28) to predict utility values. The arthritis component of the disease was measured either through HAQ-DI (n=11) or DAS28 (n=2), whereas PASI was used for the skin component (n=4). Most of the algorithms were using a linear approach (n=11). Among these linear algorithms one unit decrease of HAQ-DI improves patient’s utility by 0.1 to 0.3 units. Effect of PASI on utility was much smaller as compared to HAQ-DI (0.004 improvement in utility per unit decrease in PASI). Using these algorithms, the incremental cost-effectiveness ratios (ICER) were calculated for each biologic versus standard of care. For each biologic ICERs coefficient of variation (standard deviation/mean) was approx. 17%. CONCLUSIONS: HAQ-DI is the key influencing variable in deriving utility values for PsA patients in the current algorithms. In biologic cost-effectiveness models, ICER is sensitive to the algorithms used. The analysis suggests that there may be a need of an improved algorithm to inform cost-effectiveness models for predicting utility more accurately. This may help the healthcare decision makers to make more informed decisions.