Ires Ghielen

145 BEWARE: Results of the pilot RCT included inventory and planning of value-based committed actions and performing mindful body scans. Control condition: treatment as usual (TAU) The patients in the control group received TAU based on the current Royal Dutch Society guidelines for physical group therapy in patients with PD, consisting of movement strategies for improving balance, gait, transfers and posture [31]. No homework assignments were assigned in this condition. Ethical considerations Prior to study participation, all patients were asked to sign a written informed consent. The study was approved by the ethics committee of the VU university medical centre (study number: 13.421). Trial registration: ClinicalTrials.gov identifier: NCT02054845. Outcome measures Primary outcome measure The primary outcome measure was self-efficacy, assessed with the 10 item GSES [32]. Self-efficacy is defined as the extent or strength of one’s belief in one’s own ability to complete tasks and reach goals [33]. In the GSES, patients are asked to rate 10 specific statements on a scale from 1 to 4, with a higher rating representing better self-efficacy. Secondary outcome measures We measured symptoms of wearing-off by means of the WOQ-19, in which patients can check 19 symptoms they experience and indicate whether these symptoms usually improve after their next medication dose [29]. The BAI (range 21-84) [34] and the Beck Depression Inventory (BDI; range 0-63) [35] were used to measure anxiety and depressive symptoms, respectively. A higher score on these questionnaires indicates more (severe) symptoms. The Parkinson’s Disease Questionnaire-39 (PDQ-39) was used to assess quality of life, which contains the subscales mobility, activities of daily living, emotional wellbeing, stigma, social support, cognitions, communication, and bodily discomfort [36]. Higher scores on these subscales indicate more (severe) symptoms, e.g. lower quality of life. We measured activities of daily living with the Nottingham Extended Activities of Daily Living (NEADL) index [37]. A higher score represents more independence in performing daily life activities. To assess symptoms of freezing the Freezing of Gait (FOG) questionnaire was used, where a higher score represents more severe freezing [38]. The 10 Meter Walk Test 8