Table 5

Primary and exploratory outcome measures

Measure/author	Purpose	Time point
a) Efficacy and exploratory outcome measures for the participant
The Addenbrooke's Cognitive Examination III26	Assesses cognitive function	Baseline/post-test
Everyday Cognition Questionnaire27	Measures everyday cognition in people with movement disorders	Baseline/post-test
Pill Questionnaire37	Measures functional capacity	Baseline/post-test
Lille Apathy Rating Scale38	A scale to detect and quantify apathy	Baseline/post-test
Relationship Satisfaction Scale39	Assesses level of satisfaction in a relationship	Baseline/post-test
The Brief Resilience Scale40	Assesses the ability to recover from stress	Baseline/post-test
Interpersonal Reactivity Index41	Measures empathetic concern	Baseline/post-test
Hospital Anxiety and Depression Scale42	Assesses depression and anxiety	Baseline/post-test
Parkinson's Disease Questionnaire-3943	A Parkinson's disease-specific quality of life measure	Baseline/post-test
Dementia Cognitive Fluctuation Scale44	Assesses proxy-reported fluctuations in cognition	Baseline/post-test
The Neuropsychiatric Inventory45	Assesses presence or absence of behavioural disturbances	Baseline/post-test
EuroQoL 5D31	Used for calculation of quality-adjusted life-years	Baseline/post-test
Client Services Receipt Inventory30	Collects information about medications and services used before entering the trial and during the trial	Baseline/post-test
b) Exploratory outcome measures for the companion
Short Form-12 Health Survey46	Measures an individual's perception of their physical and mental health	Baseline/post-test
Relationship Satisfaction Scale39	Assesses level of satisfaction in a relationship	Baseline/post-test
Brief Resilience Scale40	Assesses the ability to recover from stress	Baseline/post-test
Hospital Anxiety and Depression Scale42	Assesses depression and anxiety	Baseline/post-test
Zarit Burden Interview47	Measures companion burden due to caregiving	Baseline/post-test
Dyadic Relationship Scale48	Measures positive and negative aspects of the dyadic relationship	Baseline/post-test
Relatives’ Stress Scale49	Measures perceived stress associated with caregiving	Baseline/post-test
Family caregiving role50	Measures aspects of caregiving related to satisfaction, love and anger	Baseline/post-test