Myasthenia gravis (MG) and neuromyelitis optica (NMO) are two autoimmune conditions. Autoimmune conditions occur when the immune system designed to protect the body against disease mistakenly attack healthy cells. MG results from antibodies attacking the communication channel between the brain and certain muscles, and manifests as muscle weakness. NMO also impacts on the nervous system and most commonly affects the nerve connecting the eye to the brain (the optic nerve) and the spinal column. Both conditions affect both genders and can occur at any age. In this study we wish to use the Clinical Practice Research Datalink to estimate the incidence (the number of new cases) and prevalence (number of existing cases) of both MG and NMO in the United Kingdom. These findings will be important in determining the public health impact of these conditions.
We aim to estimate the overall and age and gender-specific incidence and prevalence of myasthenia gravis (MG) and neuromyelitis optica (NMO) in a UK population based on the Clinical Practice Research Datalink (CPRD). In addition to the overall rates we also wish to estimate age- and gender-specific rates and to calculate age of onset. To achieve this we will use primary-care data from CPRD GOLD for the main analysis, but in a sensitivity analysis we will combine this with secondary-care data from the linked Hospital Episode Statistics (HES). Patients will be identified by Read code and the ICD-10 classification as appropriate. Period prevalence will be calculated for 2014, using the number of live patients registered within an up-to-standard (UTS) practice on the mid-year point (30th June 2014) as the denominator. Annual incidence will be estimated based on average annual incidence observed since 2000.
A second sensitivity analysis for MG will be presented for those cases defined as probable cases.
Christopher Morgan - Chief Investigator - Pharmatelligence Limited t/a Human Data Sciences
Alexander Cole - Collaborator - Alexion Pharma UK Ltd ( UK )
Bethan Jones - Collaborator - Pharmatelligence Limited t/a Human Data Sciences
Sara Jenkins-Jones - Collaborator - Pharmatelligence Limited t/a Human Data Sciences
HES Admitted Patient Care