*2.3. Study Selection and Data Extraction*

Two reviewers (M.K. and J.L.) independently conducted the study selection and data extraction.

Disagreement between the two researchers was resolved by discussion with a third independent reviewer (M.J.). Duplicate publications, patients diagnosed with Parkinsonism syndrome, and cases in combination with other treatments were excluded. A standardized data collection form developed during the pilot process using Excel was utilized during

the data extraction process. The extracted items were as follows: sample size and the number of dropouts, first author, year of publication, location, age, sex, disease severity, disease duration, treatment intervention, control group intervention, treatment period, and outcome variables. We contacted the corresponding author to acquire sufficient data if there was insufficient information in the published article via e-mail. EndNote X9 (EndNote version X9, Thomson Reuters, CA, USA) was used for article selection and management.
