Data collection

The primary outcome is the change in function and well-being associated with PD, measured by the validated Parkinson’s disease Questionnaire (PDQ-39) [24], which captures information about PD-related symptoms and wellbeing. The questionnaire has 39 items each on a scale of 0 (never) to 5 (always or cannot do at all). Eight dimensions are reported: mobility (MOB) (10 items), activities of daily living (ADL) (6 items), emotional wellbeing (EMO) (6 items), stigma (STI) (4 items), social support (SOC) (3 items), cognitions (COG) (4 items), communication (COM) (3 items), and bodily discomfort (BOD) (3 items). A summary index score (PDQ-39-SI) provides an overall picture of health-related-quality-of-life (HRQoL).

Secondary outcomes are changes in health behaviours, mental health and locus of control measured by four validated, self-administered questionnaires. 1. mindfulness as measured by the Freiburg Mindfulness Inventory (FMI) [25], 2. depression, anxiety and stress as measured by the DASS 21 [26], 3. locus of control as measured using the multidimensional locus of control (LOC), Form B [27], and 4. exercise and nutrition as measured in the Health Behaviours Questionnaire (HBQ)) [28].

All participants completed the study questionnaires at three time points: (T0) baseline, (T1) week 7 after the intervention participants (but not wait-list controls) had completed the intervention and (T2) 6 months after the intervention had completed for all participants (both intervention and wait-list controls).

Study questionnaires were mailed or given to participants in person. Questionnaire packages included a self-addressed return envelope, cover letter with contact details for the researchers and a request that questionnaires be completed and returned within 1 week. Baseline (T0) questionnaires were mailed to all participants. At this time, participants were also emailed a link to an electronic instructional video, detailing each component of the questionnaire. Week 7 (T1) questionnaires were distributed to the intervention participants after the final session and if a participant was absent then the questionnaire was mailed. Wait-list control participants received the questionnaire in the mail. The 6 month (T2) questionnaires were all mailed. Follow up strategies were implemented if a survey was not returned within 2 week of the sent date, consisting of phone calls and emails to the participant made by a research assistant. Follow up was ceased at 4 weeks post sent date.

We monitored participant attendance at the weekly intervention sessions. If a participant did not attend four or more sessions, this was recorded and their data excluded from the analysis. We also monitored participant adherence using a modified medical outcomes study [29] and by participants self-rating their practice of the program exercises in the week prior on a 5-point Likert scale. Intervention participants were required to complete the adherence measure prior to leaving the fourth and final sessions. All participants were mailed the adherence measure along with the other study questionnaires at the 6-month post intervention point.