Parkinsonism is a clinical syndrome characterised by symptoms such as stiffness, tremor, balance problems and slowness of movement. Roughly, seventy-five percent of parkinsonism cases are attributed to a condition called Parkinson’s Disease. People typically receive treatments with specific medications, such as a medicine called levodopa, to improve their symptoms. However, Parkinson treatments may also cause side effects such as excessive sleepiness. Physicians might prescribe additional drugs to treat such side effects, which can result in an excess number of new drugs a person is taking. This is known as a ‘prescription cascade’.
Understanding which medications people were prescribed before and after they were diagnosed with parkinsonism provides us with a picture of typical treatment pathways, as well as medications used in the treatment of potential drug side effects.
In this study, we will estimate the proportion of the population diagnosed with parkinsonism. Subsequently, we will describe patients’ treatments, including Parkinson-specific medications, co-medications and describe changes in people’s medication over time. This will help us to better understand common therapies used in this population of patients and find prescription cascades that could hint towards side effects or drug-drug interactions. Such knowledge can help inform physicians with treatment choices for people with parkinsonism to reduce the burden of side effects for patients.
BACKGROUND
There is currently no cure for Parkinson’s Disease and although current treatments could relieve some symptoms, they also cause side effects such as excessive sleepiness or impulse control disorders. Prescription cascades can often form when these side effects are identified as potential “new” diseases in a person. This is especially of concern as people diagnosed with Parkinson’s Disease typically experience multimorbidity and polypharmacy due to their age.
AIM AND OBJECTIVES
The overall aim of this project is to characterize the diagnosis and treatment pathways of patients with parkinsonism and determine potential prescription cascades.
METHODS
Data: CPRD GOLD, linked to patient-level Index of multiple deprivation
Participants: All adults >=18 and registered in CPRD GOLD with at least one year of prior continuous observation (objectives 1 and 2). For objectives 3 to 5, only people with a diagnosis of parkinsonism will be included.
Analyses for each of the five objectives:
(1) We will estimate the incidence and prevalence of parkinsonism, and its subtypes, namely Parkinson’s Disease, vascular parkinsonism and drug-induced parkinsonism, stratified by age and sex from 2007 to 2022.
(2) We will estimate the incidence and prevalence of use of antiparkinson medications, namely levodopa, dopamine agonists, MAO-B inhibitors, COMT inhibitors and amantadine, from 2007 to 2022, in both the general population and in disease strata, stratified by both age and sex.
(3) We will describe the prescription pattern of other (non-parkinson) medications in people before and after a diagnosis of parkinsonism. Moreover, we will characterise the patients by comorbidities and socioeconomic status.
(4) We will describe the treatment pathways for patients with parkinsonism. Sanky plots and sunburst plots will be used to depict treatment pathways.
(5) we will determine existing prescription cascades using Prescription Sequence Symmetry Analysis (PSSA).
The outcomes to be measured for this study are:
Diagnosis of parkinsonism and subtypes (Parkinson’s Disease, vascular parkinsonism and drug-induced parkinsonism); prescription/use of antiparkinson medications: levodopa, dopamine agonists, MAO-B inhibitors, COMT inhibitors and amantadine.
Annika Jodicke - Chief Investigator - University of Oxford
Xihang Chen - Corresponding Applicant - University of Oxford
Antonella Delmestri - Collaborator - University of Oxford
Daniel Prieto-Alhambra - Collaborator - University of Oxford
Danielle Newby - Collaborator - University of Oxford
Marta Pineda Moncusi - Collaborator - University of Oxford
Martí Català Sabaté - Collaborator - University of Oxford
Nicola Barclay - Collaborator - University of Oxford
Wai Yi Man - Collaborator - University of Oxford
Wai Yi Man - Collaborator - University of Oxford
Patient Level Index of Multiple Deprivation