Li 2015a.

Study characteristics
Methods	RCT
Participants	Setting: China N = 89 (subgroup with cognitive impairment only as they were given the intervention) Sample: recruited from the PD collaborative study carried out in the neurology department of Weihai Municipal Hospital (37% women) Age (years): Mean (95% CI) intervention group 67.5 (52.7‐71.1) control group 66.9 (53.8‐70.3) Inclusion criteria: diagnosis of PD in accordance with the UK Brain Bank criteria; cognitive impairment, including PD dementia Exclusion criteria: the presence of other conditions that can lead to cognitive dysfunction, such as delirium, stroke, severe depression, metabolic abnormalities, drug side effects, and head trauma Disease severity at baseline: HY stage 1 to 5; MDS‐UPDRS motor score mean 20.6 (SD not reported)
Interventions	Medication: cholinesterase inhibitor 1. Oral rivastigmine (3mg twice daily) for 12 months 2. Placebo (3mg twice daily) for 12 months
Outcomes	1. Rate of falls 2. Number of fallers Other outcomes reported but not included in this review
Duration of the study	12 months
Funding source	Development Plan of Medical and Health Sciences of Shandong Province (No. 2007HW020)
Notes	Fall data collected: at baseline and every week by phone calls or follow‐up evaluations for 12 months
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method of generating randomisation list not described. Quote: "The trial was a randomized, double‐blind, placebo‐controlled study of 12 months duration.”
Allocation concealment (selection bias)	Unclear risk	Insufficient information to permit judgement.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Insufficient information to permit judgement. No details provided relating to how double blinding to group allocation (medication/placebo) was performed.
Blinding of outcome assessment (detection bias) Falls and fallers	Low risk	Outcomes were recorded/confirmed in all allocated groups using the same method and the personnel recording/confirming outcomes were blind to group allocation.
Incomplete outcome data (attrition bias) Falls	Unclear risk	Data not available to assess.
Incomplete outcome data (attrition bias) Fallers	Unclear risk	Data not available to assess.
Selective reporting (reporting bias)	Unclear risk	Insufficient information to permit judgement as unable to find a published protocol or trial registration.
Method of ascertaining falls (recall bias) Falls and fallers	Unclear risk	It appears that retrospective recall was required over a short period (one week). Quote: "Phone calls or follow‐up evaluations were conducted every week to record the data related to falls.”