Asthma is a common disease, especially in the UK. Although asthma itself can have a major effect on a person's health and wellbeing, asthma treatments can also have important side effects that are harmful. Asthma treatments include inhaled (ICS) and oral (OCS) corticosteroids both of which can lead to thinning of the bones (also known as osteoporosis), and fracture. Despite the high proportion of people who have been diagnosed with asthma, little is known about how often these side effects occur. In particular, information on the risk of osteoporosis is scarce and there are no asthma specific bone protection guidelines either nationally or internationally. This has become more important with the recognition that drugs used to prevent osteoporosis and fractures can themselves lead to significant side effects.
Our purpose is to a) understand how frequently people with asthma experience an osteoporotic fracture due to corticosteroids b) to establish the current use of bisphosphonate (drugs which are used to prevent osteoporosis and fractures) and oral corticosteroids and c) examine whether or not the exposure to bisphosphonates is associated with other side effects in people with asthma.
Our study will provide guidance for patients, clinicians and policy makers. More precisely, our results will help the development of specific related bone protection guidelines, which will guide patients/clinician decision making on treatment.
The objective of this study is to understand the link between asthma, corticosteroids, osteoporosis and fractures, bisphosphonates and atypical fractures. Specifically, we are interested in the following using CPRD linked HES data:
Determine the point prevalence and incidence of osteoporosis, fragility fracture and femoral shaft and subtrochanteric (atypical) fractures within people with asthma adjusting for the appropriate confounding factors.
- Logistic regression investigating factors associated with prevalence
- Cox regression model determining association between asthma and incidence of a diagnosis adjusting for confounders
To establish the risk of fragility fractures in patients with asthma due to inhaled or oral corticosteroids.
- Nested case control study defining i) cases as asthma patients with a fragility fracture diagnosis and ii) control asthma patients without a fragility fracture diagnosis.
- Estimating the association between corticosteroids use and fragility fracture by using conditional logistic regression
The rate of bisphosphonate and steroid co-prescription in asthma and non-asthma patients.
- Establishment of the co-prescription rate in the above two populations by age, gender and calendar year over the whole period for each cohort determining any association.
- Using a Poisson regression model to determine associations between risk factors and co-prescription rate.
To examine the risk of femoral shaft and subtrochanteric fractures (known as atypical fractures) due to bisphosphonate use in people with asthma.
- Nested case control study defining i)cases as asthma patients with a femoral shaft or subtrochanteric fracture diagnosis and ii) control group as asthma patients.
- Estimate the association between bisphosphonate use and atypical fractures by using conditional logistic regression
Using CPRD linked HES data, the outcomes will be the following:
Primary outcomes
- The point prevalence and incidence of osteoporosis, fragility fracture and subtrochanteric and femoral shaft (atypical) fracture in people with asthma.
- The risk of fragility fracture in people with asthma associated with inhaled (ICS) or oral (OCS) corticosteroids.
- The co-prescription rate of ICS/OCS and bisphosphonates in asthma patients.
- The risk of femoral shaft and subtrochanteric (atypical) fracture associated with bisphosphonate use in patients with asthma.
Secondary outcomes
- The incidence of fragility fractures in people with asthma associated with inhaled or oral corticosteroids.
Tricia McKeever - Chief Investigator - University of Nottingham
Christos Chalitsios - Corresponding Applicant - University of Nottingham
Dominik Shaw - Collaborator - University of Nottingham
Opinder Sahota - Collaborator - Nottingham University Hospitals
Richard Hubbard - Collaborator - University of Nottingham
HES Admitted Patient Care;HES Outpatient;Patient Level Index of Multiple Deprivation;Practice Level Index of Multiple Deprivation