Table 3.

Scoring system for quality of included papers

Sample of patients	Sample size	Definition & diagnosis of PD	Breakdown of ethnicity	Data Collection	Discussion & analysis	Scoring
Not specified	< 30	None	2 divisions only	2nd/3rd party report collection	No attempt to explain findings	0
Specific group e.g. prisoners	≥ 30	Appropriate tool by non-clinician	More than 2 divisions	First hand collection	Explanation for findings offered	1
General Population	Considered e.g. power calculation	Appropriate tool by clinician				2

(QUALITY: 0-3; low, 4-6; moderate, 7-9; high)