Spasticity is a muscle disorder characterized by muscle stiffness, spasms or tightness in the affected arm or leg with pain and abnormal positioning of the limb. Consequently, there may be difficulties using the arm or leg in everyday activities including walking, sitting and standing. Impairment of the quality of life will depend on the severity and location of the affected muscles. Spasticity affects over 25% of patients within the first 6 weeks after a stroke. Of approximately 110,000 strokes per year in England around 33,000 result in upper limb and around 27,600 in lower limb spasticity. Physical therapy and drug treatment are essential for avoiding severe spasticity and pain. Drug treatment includes muscle relaxants. Botulinum toxin is a nerve toxin used medically in very low doses to treat certain muscular conditions. It is administered by intramuscular injection into the target muscle and is more effective than muscle relaxants in decreasing pain and increasing mobility. Purpose of the study and the potential importance of the findings: The current study aims to study patients with stroke-related spasticity who are given botulinum toxin and then to compare their healthcare encounters, lab tests, referrals and medication use before and after treatment.
The study objective is to develop an algorithm to ascertain patients with post-stroke spasticity of the upper or lower limb who are administered Botulinum toxin type A (BoNT-A) and to quantify the healthcare resource utilisation (HCRU) in the year before and the year after their first BoNT-A administration. A cohort of patients with post-stroke spasticity treated with BoNT-A will be defined from the Clinical Practice Research Database (CPRD) and Hospital Episode Statistics (HES). The HRCU outcomes consist of hospitalisations, days in hospital, hospital procedures, GP visits, and prescriptions for muscle relaxants, anxiolytics and other medications. The rate of HCRU use will be calculated by dividing the number of HRCU events by the total person-time of observation in the 12 months before and the 12 months after the first BoNT-A injection using the period prior to BoNT-A injection as the reference. Wald-tests from conditional Poisson regression models will be used for each HCRU measure separately.
The outcomes of interest are HCRU in the year before and in the year following BoNT-A use. Secondary HRCU components are the number of hospital procedures and the use of muscle relaxants, anxiolytics and other medications.
Carlos Martinez - Chief Investigator - Institute for Epidemiology, Statistics and Informatics GmbH (Pharma Epi)
Carlos Martinez - Corresponding Applicant - Institute for Epidemiology, Statistics and Informatics GmbH (Pharma Epi)
Christopher Wallenhorst - Collaborator - Institute for Epidemiology, Statistics and Informatics GmbH (Pharma Epi)
Stephan Rietbrock - Collaborator - Institute for Epidemiology, Statistics and Informatics GmbH (Pharma Epi)
HES Admitted Patient Care;HES Outpatient;ONS Death Registration Data;Patient Level Index of Multiple Deprivation;Practice Level Index of Multiple Deprivation