Chung 2010.

Study characteristics
Methods	RCT
Participants	Setting: USA N = 23 Sample: recruited from Oregon Health & Sciences University Movement Disorders Clinic (21% women) Age (years): mean (SD) 68.3 (10.8) Inclusion criteria: diagnosed with probable idiopathic PD; responsive to levodopa replacement therapy; baseline frequency of falling or nearly falling ≥2 times per week; ambulatory about the home either independently or with a walker or cane Exclusion criteria: freezing or non‐CNS contributors to falls such as orthostasis, arthritic impairments, or neuropathy; currently using cholinesterase inhibitors or drugs with anticholinergic or sedative‐hypnotic properties; cognitive impairment (Mini‐mental State Examination score of <25); unstable medical or psychiatric problems; Hoehn and Yahr stage 5 Disease severity at baseline: HY mean (SD) 3.2 (0.4), UPDRS motor score mean (SD) 24.7 (8.6)
Interventions	Medication: cholinesterase inhibitor 1. Donepezil (5 mg) for 3 weeks, increasing to 10 mg for 3 weeks. Plus washout period for 3 wks. Plus placebo (5 mg) for 3 weeks, increasing to 10 mg for 3 weeks 2. Placebo (5 mg) for 3 weeks, increasing to 10 mg for 3 weeks. Plus washout period for 3 weeks. Plus Donepezil (5 mg) for 3 weeks, increasing to 10 mg for 3 weeks
Outcomes	1. Rate of falls 2. Number of fallers (data provided by trial authors on request) 2. Number reporting a fall‐related fracture 3. Number and type of adverse events Other outcomes reported but not included in this review
Duration of the study	15 weeks
Funding source	Pfizer Inc ‐ this was an investigator‐initiated project and Pfizer Inc did not design or monitor the study or receive the data or influence the writing of the manuscript. Also supported by a Veterans Administration Career development Award, US Public Health Service Grant (ULIRR024140‐02), and the NIH (R01‐NS21062 and NIA AG006457)
Notes	Fall data collected: at baseline and daily onto postcards which accumulated data for 1 week of monitoring, and collected for 6 weeks per phase. Postcards were mailed back to the investigator weekly
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method of generating the randomisation list not described. Quote: "The trial was a randomized, crossover, double‐blind study."
Allocation concealment (selection bias)	Unclear risk	Insufficient information to permit judgement.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Blinding of participants and personnel implementing the interventions ensured, and unlikely that the blinding could have been broken. Quote: "Drug and placebo tablets were identical in appearance and were provided by Pfizer."
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.
Blinding of outcome assessment (detection bias) Fractures	Unclear risk	Unclear how data regarding fractures was collected.
Incomplete outcome data (attrition bias) Falls	High risk	See appendix for method of assessment
Incomplete outcome data (attrition bias) Fallers	Low risk	See appendix for method of assessment
Selective reporting (reporting bias)	Unclear risk	The study protocol is available (NCT00611481) and all of the study’s pre‐specified (primary and secondary) outcomes that are of interest in the review have been reported in the pre‐specified way, however the protocol was registered after the trial was completed.
Method of ascertaining falls (recall bias) Falls and fallers	Low risk	The study used concurrent collection of data about falling with monthly, or more frequent, follow‐up by the researchers. Quote: “The primary outcomes were fall and near‐fall frequency determined using daily event recording by the subjects onto postcards which accumulated data for 1week of monitoring, and collected for 6 weeks per phase. Postcards were mailed back to the investigator weekly.”