Table 3.

Data to be extracted

Extraction domain	Data to extract
General study information	Intervention studied*
	Status of study*
	Year of publication*
	Year of registration†
	Year of completion/termination*
	Named sites†
	Number of countries†
	Lead site country†
Eligibility criteria	Age limits†
	Disease duration*
	Hoehn and Yahr stage*
	Hoehn and Yahr on/off state*
	Inclusion criteria present: cognition†
	Definition of cognition criterion†
	Inclusion criteria present: depression†
	Definition of depression score†
	Inclusion criteria present: drug naive*
	PD drug stability†
	Changes to PD drugs permitted?†
Outcome measures	Primary outcome measures*
	Other outcome measures*
	Outcome domains*
Study design	Primary endpoints met*
	Other endpoints met*
	Phase of trial*
	Number of sites*
	Number of arms*
	Number of participants enrolled/estimated*
	Attrition (control arm)*
	Attrition (active arm)*
	Level of blinding†
	Type of control*
	Stratification parameters†
	Wash out present†
	Wash in present†
	Overarching design type and details†
	Dose ranging†
	Study duration (baseline to final visit)*
	Number of follow-ups*
	Follow-up frequency*
	Treatment extension†

*Required for planned analyses.

†Other exploratory extraction fields.

PD, Parkinson’s disease.