Statistics from Altmetric.com
Despite the increasing global importance of Parkinson's disease (PD), its exact incidence in the general population is not known. Comparing published studies, incidence rates from 1.5 to 19/100 000 person-years have been reported but such differences cannot simply be attributed to between-population differences in PD risk as no two studies have used the same case ascertainment strategy.1 We have previously published the results of a community-based study of incident parkinsonism including PD in Cambridgeshire, UK: CamPaIGN (Cambridgeshire Incidence of PD from GP to Neurologist).2 We now report the findings of a novel second incidence study in the same base population, using the same case ascertainment strategy: PICNICS (Parkinsonism: Incidence and Cognitive and Non-motor heterogeneity In CambridgeShire). This unique undertaking enables us to present a comparative analysis of these studies, representing the most complete set of PD incidence data yet reported in a defined population.
The PICNICS study recruited newly diagnosed cases of PD and parkinsonism resident in Cambridgeshire between 1 April 2008 and 31 January 2010. Detailed methods including inclusion and exclusion criteria are available from the author. To summarise, case ascertainment was performed using a service-based screen of the normal routes of UK/National Health Service (NHS) healthcare referral. All general practitioners (GPs) and hospital specialists working with suspected/newly diagnosed PD operating in the county were regularly contacted by mail and electronically throughout the study period. They were instructed to refer all consenting cases …