Terms used in this evidence summary
The clinician global impression of change (CGI‑C) measures the change in clinician global impression relative to a baseline state at the beginning of the study. This change is rated as: very much improved, much improved, minimally improved, no change, minimally worse, much worse, or very much worse. Patients with 'improvement' are those rated as very much improved, much improved or minimally improved.
The non-motor symptom scale assesses non-motor symptoms that may be associated with Parkinson's disease. This consists of 30 questions for the patients to answer yes or no to. Points are scored out of 30. Scores that are 10 or lower indicates mild, 10 to 20 indicated moderate and over 20 indicates severe (Parkinson's UK).
People with Parkinson's disease can experience motor fluctuations (particularly when the dose of levodopa begins to wear off), which they often describe as being turned 'on' and 'off'). On and off time was recorded in participant diaries in the RCTs. Participants reported whether they were: 'on' with no dyskinesia, 'on' with no troublesome dyskinesia (not interfering with function or causing meaningful discomfort), 'on' with troublesome dyskinesia, 'off' (lack of mobility [bradykinesia or akinesia]), or asleep.
The Parkinson's disease questionnaire (PDQ‑39) is a 39‑item patient-reported rating scale that measures Parkinson's disease-specific, health-related quality of life. It covers 8 areas: mobility, activities of daily living (ADL), emotional wellbeing, stigma, social support, cognition, communication and bodily discomfort. Lower scores indicate better health-related quality of life. PDQ‑39 total scores range from 0 to 800 (personal communication: Bial January 2017). The total score can be summarised into the PDQ‑39 summary index score (range of scores 0 to 100). See Peto et al. (2001) for more information.
The Parkinson's disease sleep scale allows health and social care practitioners and people with Parkinson's disease to self-rate and quantify the level of sleep disruption being experienced in order to target treatment appropriately. It consists of 15 questions for the person to answer on a scale of 0 to 10, 0 for awful or always and 10 for excellent or never (Parkinson's UK).
The patient global impression of change (PGI‑C) measures the change in the person's global impression relative to a baseline state at the beginning of the study. This change is rated as: very much improved, much improved, minimally improved, no change, minimally worse, much worse, or very much worse. People with 'improvement' are those rated as very much improved, much improved or minimally improved.
UPDRS is the unified Parkinson's disease rating scale used to assess symptoms associated with Parkinson's disease. It consists of: mentation, behaviour and mood (I); activities of daily living (II); motor examination (III); complications of therapy (IV); modified Hoehn and Yahr staging (V); and Schwab and England scale (VI). The questions can be answered in the on or off state. Lower scores are better. See Shrag et al (2006) and Shulman et al. (2010) for more information.