Change in the incidence of Parkinson's disease in a large UK primary care database

Abstract

Parkinson's disease (PD) has the fastest rising prevalence of all neurodegenerative diseases worldwide. However, it is unclear whether its incidence has increased after accounting for age and changes in diagnostic patterns in the same population. We conducted a cohort study in individuals aged ≥50 years within a large UK primary care database between January 2006 and December 2016. To account for possible changes in diagnostic patterns, we calculated the incidence of PD using four case definitions with different stringency derived from the combination of PD diagnosis, symptoms, and treatment. Using the broadest case definition, the incidence rate (IR) per 100,000 person years at risk (PYAR) was 149 (95% CI 143.3-155.4) in 2006 and 144 (95% CI 136.9-150.7) in 2016. In conclusion, the incidence of PD in the UK remained stable between 2006 and 2016, when accounting for age and diagnostic patterns, suggesting no major change in underlying risk factors for PD during this time period in the UK.

Fig. 1. Graphs showing incidence of Parkinson’s disease in UK between 2006 and 2016 using four case definitions.

The topmost graph shows the incidence using the broadest case definition. The three lower graphs show the incidence using the more stringent case definitions.

Fig. 2. Incidence of Parkinson’s disease in THIN increasing with increasing age between 2006 and 2016 using all case definitions.

The topmost graph shows the incidence using the broadest case definition. The three lower graphs show the incidence using the more stringent case definitions.

Fig. 3. Incidence of Parkinson’s disease by regions of the UK using the broadest case definition.

Incidence of Parkinson’s disease using the broadest case definition (diagnosis Read code OR symptom Read code OR at least 1 prescription of antiparkinsonian medication) per 100,000 PYAR by former Strategic Health Authority Regions from 2006 to 2016.