Table 2.

Referenced cohort studies and patient association

Study/association	Description
The Rotterdam Study [26, 27]	From April 2020 to December 2021, seven questionnaires were distributed to community-dwelling participants of the ongoing population-based Rotterdam Study in the district Ommoord in Rotterdam, the Netherlands. These questionnaires covered a range of topics, including COVID-19-related symptoms, socioeconomic factors, lifestyle, and healthcare utilisation. The frequency of the questionnaires was based on the COVID-19 infection curves in the Netherlands
PRIME-XS [20]	This single-centre, cross-sectional study began in September 2020 and involved individuals with parkinsonism and their primary informal caregivers in the catchment area of Royal United Hospital Bath NHS Foundation Trust in the United Kingdom. Participants were provided with a questionnaire that could be completed by the individuals with parkinsonism themselves, their caregivers, or a research assistant over the phone. The survey included questions on COVID-19-related symptoms, healthcare utilisation, sociodemographic factors, medication use, and PD-specific measures
PRIME-NL [28, 29]	This prospective, observational study is ongoing from January 2020 through December 2025 and includes individuals diagnosed with Parkinson’s disease or atypical parkinsonism who are receiving treatment in one of the four community hospitals that form the PRIME Parkinson care region of the Netherlands. The study aims to analyse variations in care and their impact on perceived quality of life by collecting data from healthcare claims and annual questionnaires completed by persons with parkinsonism, their caregivers, and healthcare providers
Bialystok PLUS [13, 30–32]	The research project ‘Rise or fall? Short- and long-term health and psychosocial trajectories of the COVID-19 pandemic’ was embedded within the Bialystok PLUS cohort study. It examines the short- and long-term health and psychosocial trajectories in the general population during the COVID-19 pandemic. It includes research centre visits by post-COVID-19 individuals, a general population survey using a CAWI questionnaire, and the analysis of the impact of the pandemic on mental health as part of the COH-FIT project
The Parkinson’s Association [33]	The Dutch Parkinson’s Association represents individuals with Parkinson’s disease or parkinsonism, and their loved ones. This association organises meetings and courses, provides up-to-date and objective information, and is a critical advocate in political and media settings. It also safeguards quality of care and ensures the voice of those involved with Parkinson’s disease or parkinsonism is heard in scientific research. Both patient representatives involved in PREP-ND were affiliated with this association