Background A recent survey from Canada on 30,000 individuals with intellectual disabilities (ID) and 1.5 million from the general population showed a fracture rate three times higher in people with ID, confirming the findings of smaller studies over the past 30 years. However, patients with ID are not identified as a high-risk group and their routine health check does not address bone health. The underestimate of these patients' fracture risk probably stems from the lack of UK specific data, and from the limited knowledge on risk factors for fractures in these patients.
Study proposal Using data from the Clinical Practice Research Datalink and linked databases, we'll compare rates of fractures between patients with ID and the general UK population and examine risk factors for fractures in these patients. This will allow us to design a fracture risk assessment tool specific for people with ID. This is important because the currently available fracture risk assessment tools do not take into account risk factors for fractures which are common in these patients. As our study results will help identify patients with ID at risk of fractures, available prevention strategies could be used to reduce the incidence of these events in these patients.
Despite evidence from other countries of increased fracture risk in patients with intellectual disabilities (ID), UK based epidemiological data is lacking and the risk factors for fractures in these patients are not clearly established.
In a Fracture Incidence Study, we will compare the rates of a) all fractures, b) fragility fractures and c) hip fractures between patients with ID and general population subjects in the Clinical Practice Research Datalink (CPRD).
In a Fracture Risk Assessment Study, we'll investigate all the predictors included in the most recent available version of Qfracture, a fracture risk calculator for the general population recommended by the National Institute of Health and Care Excellence, and additional potential risk factors more specific to ID patients. These will include cause of ID (e.g. Down's syndrome), associated illnesses (e.g. cerebral palsy), medication (e.g. antipsychotics), and others. We will construct and validate a fracture risk assessment tool using a derivation cohort and a validation cohort within the CPRD. Two thirds of the CPRD practices will be randomly assigned to the derivation dataset, on which we will construct the model using Cox regression analysis, and one third to the validation dataset, by which we will evaluate its predictive accuracy.
Incidence of fracture in the UK population with intellectual disabilities
- Incidence of fracture in the general UK population
- Risk factors determining risk of fracture in people with intellectual disabilities and their relative contributions to fracture risk
Margaret Smith - Chief Investigator - University of Oxford
Margaret Smith - Corresponding Applicant - University of Oxford
Daniel Prieto-Alhambra - Collaborator - University of Oxford
Gary Collins - Collaborator - University of Oxford
Jan Roast - Collaborator - Oxfordshire Family Support Network
Lei Clifton - Collaborator - University of Oxford
Tim Holt - Collaborator - University of Oxford
Timothy Andrews - Collaborator - Oxford Health NHS Foundation Trust
HES Admitted Patient Care;ONS Death Registration Data;Patient Level Index of Multiple Deprivation