Outcome of fractures in people with intellectual disabilities

Study type
Protocol
Date of Approval
Study reference ID
20_000061
Lay Summary

In a previous study using the CPRD database and funded by the National Institute of Health Research, we found that people with intellectual disabilities (ID) have higher fracture rates and younger age at fracture than the general population. The study included the largest sample of people with ID ever studied. It confirmed and expanded the results of several previous smaller studies. The difference in fracture incidence rates was particularly marked for hip fracture, one of the most severe fractures, for which the rate found in our study was approximately three times higher in people with ID than in the control subjects. In current guidelines, patients with ID are not identified as at high risk of osteoporosis (brittle bones) and fractures, and in clinical practice there is widespread lack of awareness of the problem. Clinical experience shows that in people with ID, fractures can be particularly serious, due to difficulties in accepting immobilisation, limited compliance with rehabilitation, and various pre-existing physical disabilities. Moreover, the consequences of hip fracture could be particularly severe. However, to our knowledge, this problem has never been studied in these patients.
In this study, we will compare the incidence of negative outcomes of fractures, such as impaired healing, impaired mobility, psychological distress, in people with and without ID. We will also compare mortality after hip fracture and after any fracture. Our overarching aim is to improve the evidence base supporting a fracture prevention programme for people with intellectual disabilities.

Technical Summary

In a previous CPRD study funded by the National Institute of Health Research we found that people with intellectual disabilities (ID) have higher fracture rates and younger age at fracture than the general population. The study included the largest cohort of ID people ever studied. The difference was particularly marked for hip fracture, for which incidence rates in adults aged ≥ 50 years with ID compared to those without ID was almost four times as high in men and over twice as high in women. In current guidelines, ID patients are not identified as at high risk of osteoporosis and fractures, and in clinical practice there is widespread lack of awareness of the problem. In people with ID, fractures can be particularly serious, due to difficulties in accepting immobilisation, limited compliance with rehabilitation, and pre-existing physical disabilities. The consequences of hip fracture could be particularly severe. However, to our knowledge, this problem has never been studied in these patients.
In this study, we will compare the incidence of negative outcomes of fractures, namely impaired healing, impaired mobility, and psychological distress, in people with and without ID. We will also compare mortality after any fracture and after hip fracture. ID patients and fractures will be identified according to the same Read codes/medcodes used in our “parent study”. For each person with ID we’ll select up to five people without ID, matched on year of index, age at index and gender. Outcomes will be compared between these groups and reported as relative risks with confidence intervals. Using Poisson regression with robust variances or equivalently log binomial regression we will investigate the influence of a range of pre-specified covariates and potential confounders.
Our overarching aim is to improve the evidence base supporting a fracture prevention programme for people with intellectual disabilities.

Health Outcomes to be Measured

Primary outcomes
Impaired healing, impaired mobility within one year of any fracture
Mortality from any cause within one-year of any fracture, and of hip fracture

Secondary outcomes
Psychological morbidity within six months of any fracture
Mortality within 30-days of hip fracture

Collaborators

Margaret Smith - Chief Investigator - University of Oxford
Margaret Smith - Corresponding Applicant - University of Oxford
Tim Holt - Collaborator - NHS BATH AND NORTH EAST SOMERSET, SWINDON AND WILTSHIRE CCG

Former Collaborators

Margaret Smith - Collaborator - University of Oxford

Linkages

HES Admitted Patient Care;ONS Death Registration Data;Patient Level Index of Multiple Deprivation;Practice Level Index of Multiple Deprivation