Other project members
Olof Björneld, doctoral student at the eHealth Institute, DISA and IT engineer at Kalmar County Council
Amanda Pettersson, medical student at Linköping University and Kalmar County Council
Lars Brudin, professor at Linköping University and chief physician at Kalmar County Council
Pär Wanby, associate professor at Linnaeus University, Linköping University and chief physician at Kalmar County Council
Rebecca Nobin, doctoral student at Lund University and chief physician at Kalmar County Council
Martin Carlsson, associate professor at Linnaeus University and chief physician at Kalmar County Council
Linnaeus University, Kalmar County Council
Kalmar County Council and the Kamprad Family Foundation
1 Jan 2019–1 Jan 2021
Biomedical science (Department of Medicine and Optometry, Faculty of Health and Life Sciences)
More about the project
Sweden is one of the countries where osteoporosis-related fractures are most common. Every year, around 70 000 people suffer from this types of fractures, which cause great suffering to the affected, but also considerable economic costs to society.
An underlying cause of osteoporosis-related fractures is side effects of some types of drugs. The drugs can affect both the mineral density of the skeleton and its quality, but also the balance and fall risk of the drug users. A group of drugs that have these types of side effects are drugs that prevent seizures. They are often referred to as antiepileptic drugs, i.e. medicines for epilepsy, but they are now used in several different types of diseases and conditions. Some of these anticonvulsant drugs affect vitamin D turnover, which is believed to be one of the mechanisms behind the increased risk of osteoporosis and fractures.
To predict the risk of osteoporosis-related fractures, a risk assessment tool, FRAX, has been developed and is now used in health care. However, anticonvulsant drugs are not included as a risk factor in FRAX at present, despite the knowledge of the increased risk of osteoporosis fractures. The fact that this type of drugs are not included in the assessment tool has probably led to the risks being poorly known in health care.
A type of X-ray examination, called DXA, is currently used to measure bone mineral density. Patients with the same bone mineral density, may have different bone quality, which is why a newer method, which estimates bone quality based on previous DXA images, has been developed. The method is called TBS. The value of TBS has been studied in various patient groups with an increased risk of osteoporosis, but not in patients with antiepileptic drugs.
Objectives and goal
This project has two objectives. The first is to develop an index to estimate the risk of osteoporosis fractures in patients using antiepileptic drugs. The index is based on five previously proposed risk factors (age, gender, BMI, type of diagnosis and type of drug) and should show how the various factors affect the fracture risk in patients. The index should be able to be used in the management of the individual patient, thus being a support in the quest of finding and treating the right patients with medicines for osteoporosis. The second objective is to assess the value of the measures of bone mineral density and bone quality to predict osteoporosis fractures.
The project uses patient data from the electronic health record (EHR) system in the Kalmar Region from the years 2008 to 2019. Data from a total of about 46,000 participants are included, half of which are patients who were prescribed antiepileptic drugs and the other half are a matched control group. Patients are followed from being included in the EHR until they get an osteoporosis-related fracture, no longer live in Kalmar County or decease.
The index is constructed based on the fracture risks that patients with different factors have and based on the relationships between osteoporosis-related fractures and measures from DXA and TBS, the value of the various methods are estimated.
The five proposed risk factors all appeared as statistically significant and were used to create the index. In the quarter of patients with the lowest index, the 10-year risk of osteoporosis-related fractures was about 3%, while in the quarter with the highest index the corresponding risk was 27%. In current guidelines, the healthcare is recommended to investigate patients with a 10-year risk of 15% or more with a bone density (DXA) measurement.
In terms of the value of bone mineral density and bone quality, the project has shown that both bone mineral density measured in the hip and TBS measured in the lower spine contribute to predicting osteoporosis fractures. However, bone mineral density measured in the lower spine does not predict fractures.
The project is part of the research in the eHealth Institute, eHealth – Improved Data to and from Patients, and Linnaeus University Centre for Data Intensive Sciences and Applications research groups.