Objective: Estimate the cost of disease and falls among people with Parkinson's disease living in Hong Kong.

Design: Prospective cost-utility analysis (base year 2021) with one baseline and two follow-up assessments at 6 months and 12 months Participants: Community-dwelling participants with Parkinson's disease of both genders of any age. Intervention: Nil Outcome measures: Self-reported questionnaires will be used to obtain information about the healthcare utility. In addition, the number of falls, the severity of Parkinson' disease assessed using the MDS-Unified Parkinson's Disease Rating Scale, level of disability using the Hoehn and Yahr scale, balance using the Mini Balance Evaluation Systems Test and Activities-specific Balance Confidence (ABC) scale, risk of falls using Falls Efficacy Scale International and quality of life using the Short-form Health survey (SF-36) will be assessed. Predictors of cost include fall frequency, balance status, disease severity, level of disability, quality of life, and duration of disease. Analysis: A multiple regression analysis will be conducted to determine which predictor (independent variable) influence the overall cost. The level of statistical significance (α) will be set at p\<0.05. A Tornado plot will be constructed for the individual items of both direct and indirect cost having the minimum and maximum range set at the 25th and 75th percentile. Two-way analysis of variance (ANOVA) will assess the differences in healthcare cost among frequent, in-frequent and non-fallers. Spearman's or Pearson correlation coefficient will assess correlations between quality of life and healthcare cost; disease severity and healthcare cost; falls frequency and healthcare cost. Benefits to healthcare and health Cost-estimation highlights information required to enhance the health care service for the target population. Through a similar study among patients with cerebellar ataxia, our team demonstrated specific challenges that need additional support from the policy-makers such as employment following disability, visits to specialists, home-care, and community participation for people with cerebellar ataxia in Hong Kong. This study will highlight the strength and weakness of the current healthcare system to people of Hong Kong with Parkinson's disease, this will inform the challenges for the healthcare requiring additional attention which in turn will have a beneficial impact on the future service.