Chapter 4 36 Abstract Objectives To estimate the economic burden expressed in costs and quality of life of the postsurgical treatment of peri- and/or intra-articular fractures in the lower extremity from a societal perspective. Design and setting This is a quantitative study as it aims to find averages and generalize results to wider populations. The design is a cost–of-illness and quality of life study focusing on costs (in euros), Activities of Daily Living (ADL) and Quality of Life (Qol) in patients with peri- and/or intra-articular fractures of the lower extremities. Surgically treated trauma patients with peri- and/or intra-articular fractures of the lower extremities during 26 weeks follow-up. Patients were included from 4 hospitals in the Netherlands. Main outcome measures Costs, ADL and Quality Adjusted Life Years (QALY). Methods Cost of illness was estimated through a bottom-up method. The Dutch EQ-5D-5L questionnaire was used to calculate utilities while Lower Extremity Functional Scale (LEFS) scores were used as a measure of ADL. Non-parametric bootstrapping was used to test for statistical differences in costs. Subgroup analyses were performed to determine the influence of work status and further sensitivity analyses were performed to test the robustness of the results. Results Total average societal costs were € 9,836.96 over six months. Unexpectedly, total societal and healthcare costs were lower for patients with a paid job relative to patients without. Sensitivity analyses showed that our choice of a societal perspective and the EuroQol as our primary utility measurement tool had a significant effect on the outcomes. The ADL at baseline was 10.4 and at 26 weeks post-surgery treatment 49.5. The QoL was at baseline 0.3 and at 26 weeks post-surgery treatment 0.7. These findings are indicative of a significantly improved ADL and QoL (p<0.05) over time. Conclusions This study revealed a substantial economic burden in monetary terms and effect on QoL of patients with peri- and/or intra-articular fractures of the lower extremities during 26 weeks follow-up.