Chapter 4 38 Elkerliek Hospital, Helmond; Viecuri Medical Center, Venlo; and Maxima Medical Center, Veldhoven) between October 2017 and September 2018, as part of a larger prospective cohort study.16 The patients were included according to the inclusion and exclusion criteria of the study protocol of Kalmet et al.16 Surgically treated trauma patients with peri- and/or intra-articular fractures of the lower extremities (i.e. pelvic fractures, acetabular fractures, distal femur fractures, tibial plateau fractures, pilon fractures, calcaneal fractures and talar fractures) were eligible for inclusion if they were 18 years or older. Patients with pathological fractures, shaft fractures treated with intra-medullary nailing, or fractures treated with external fixation, and patients with amputations of (parts of) the lower extremity, were excluded. Patients with cognitive dysfunction due to a severe neurotrauma or to concomitant (mental) illness were also excluded.16 All patients underwent a non-weight bearing regime for 6–12 weeks followed by partial weight bearing with a 25% increase in fracture loading every week according to the existing (AO-) guidelines.5 The baseline characteristics in the study were collected from the electronic medical records by two researchers (PK and CM) and included: age at time of fracture, gender, ASA (American Society of Anesthesiologists) typology assessing the fitness of patients before surgery, i.e. type 1–6) classification,17 Charlson-comorbidity score (classifying prognostic comorbidity, a higher score representing additional comorbidities),18 type of fracture, and the length of stay in hospital (in days). Primary outcome measures include costs, the Activity of Daily Living (ADL) and the Quality of life (QoL). These were collected through patient questionnaires. Patient-selfperceived outcome questionnaires were taken at baseline, week 2, 6, 12 and 26 postsurgery. The costs were measured in three categories: healthcare costs, productivity costs and patient and family costs. The iMTA (Institute for Medical Technology Assessment) Medical Consumption Questionnaire (iMCQ) was used to measure all healthcare consumption by the participants during each follow-up period and included medication costs, visits with General Practitioners (GP), medical specialists, occupational physicians, therapists (physical therapists, dieticians, occupational therapists, speech therapists, homeopaths and psychologists), social workers, emergency rooms visits, ambulance transportation, hospital admittance, homecare (domestic help, help with ADL and nursing), admittance to rehabilitation centers and admittance to assisted living centers.19 The iMTA (Institute for Medical Technology Assessment) Productivity Cost Questionnaire (iPCQ) was used to measure work absence and the number of hours the participants were replaced for unpaid work.20 Patient and family costs were estimated with the iMCQ and consisted of travel costs. Following Dutch guidelines, a bottom-up approach was used for the present study.21,22 For the valuation of costs, the reference prices from the Dutch costing