Comparison 1. Exenatide vs placebo (60 weeks post‐baseline).

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1.1 PD motor impairment ‐ MDS‐UPDRS Part III (off medication)	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
1.2 HRQoL ‐ PDQ‐39 SI	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
1.3 HRQoL ‐ EQ5D	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
1.4 HRQoL ‐ EQ5D‐VAS	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
1.5 Adverse events ‐ weight loss (kg) (assessed at 48 weeks post baseline)	1		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
1.6 PD motor impairment ‐ MDS‐UPDRS Part III	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
1.7 PD motor impairment ‐ UDysRS	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
1.8 Non‐motor impairment ‐ MDS‐UPDRS Part I	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
1.9 Non‐motor impairment ‐ NMSQuest	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
1.10 Activities of daily living ‐ MDS‐UPDRS Part II	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
1.11 Psychological outcomes ‐ Mattis DRS	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
1.12 Psychological outcomes ‐ MADRS	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only