Many fractures are early-warning signs of osteoporosis. Yet in everyday clinical care they often go unrecognized and undocumented as warning signs, according to a new nationwide Austrian study by the Complexity Science Hub (CSH) and the Ludwig Boltzmann Institute for Osteology (LBI Osteology). Men are affected more often.
Osteoporosis, a disease in which bones lose density and stability, is among the most common conditions of old age and substantially increases the risk of fractures. Yet it is often diagnosed only after a first, typical "osteoporotic fracture," such as a hip fracture.
The new study by the Complexity Science Hub and LBI Osteology published in the journal Bone provides the first comprehensive, nationwide look at how osteoporosis and various fracture types co-occur in Austrian hospital records. Its results show that fractures are usually part of a complex pattern of multiple conditions – underscoring the need for consistent osteoporosis screening at the time of a fracture.
MORE THAN ONE CAUSE
Bone fractures rarely have a single cause. Bone mineral density is only part of the picture – comorbidities, the risk of falling, and overall health status also play an important role.
To better understand these connections, the research team analyzed Austrian hospital data on more than 1.7 million patients aged 50 to 79, drawn from insurance claims between 2003 and 2014. Rather than studying individual conditions in isolation, the researchers examined which diagnoses tend to co-occur with osteoporosis and different fracture types.
"Health claims data at this scale lets us see osteoporosis and fractures not as isolated diagnoses, but as part of a much larger, interconnected pattern of conditions over time. That's the kind of picture only a systematic, population-wide analysis can give us," says Elma Dervic , postdoctoral researcher at CSH.
"In clinical practice, osteoporosis and bone fractures often occur alongside many other conditions, such as cardiovascular diseases, metabolic disorders, or neurological disorders," explains Martina Behanova , the study's first author and senior researcher at LBI Osteology.
Roland Kocijan , head of the Department of Osteology and Rare Bone Diseases at Hanusch Hospital Vienna, adds: "To reduce the risk of further fractures, we recommend taking a patient's entire health profile into account. Our findings underscore the importance of a thorough evaluation for osteoporosis following a bone fracture in order to prevent further fractures."
UNEVEN DIAGNOSIS ACROSS FRACTURE TYPES
The study also found that osteoporosis is not systematically documented for many fracture types – even though these fractures often point to underlying bone weakness and, in some cases, already qualify as classic fragility fractures. The differences between fracture types were especially pronounced: hip fractures were most frequently associated with a documented osteoporosis diagnosis, particularly among women over 60.
Other fractures, though – especially of the forearm, upper arm, and pelvis – are still not consistently recognized in clinical practice as signs of osteoporosis. Yet they already meet the criteria for an established osteoporosis diagnosis and call for prompt evaluation and the start of targeted osteoporosis therapy to prevent further fractures.
Particularly alarming is that fractures often do not occur in isolation but are closely associated with fractures in other parts of the skeleton. "Every fragility fracture should therefore be viewed as a warning sign that signals the need to interrupt a cascade of fractures at an early stage," says Kocijan.
It should be noted, however, that the study captured only inpatient hospital stays; fractures treated on an outpatient basis – common for these fracture types – could not be included.
A DIAGNOSTIC GAP FOR MEN
The study also revealed marked differences between women and men. While osteoporosis in women was more often documented alongside various chronic conditions such as osteoarthritis, in men the diagnosis frequently came only after a fracture had already occurred.
Notably, osteoporosis was diagnosed or documented in connection with fractures far less often in men and in patients aged 50 to 69. At the same time, men in this age group more frequently had injury- and alcohol-related comorbidities.
"Osteoporosis in men may be diagnosed too late," says Dervić. "That means we are missing important opportunities to intervene early and prevent further fractures. Earlier diagnosis can be critical for protecting bone health in the long run."
About the study
The study " Sex- and age-specific comorbidity networks associated with osteoporosis and fragility fractures in nationwide data " by M. Behanova, R. Kocijan and E. Dervic was published in the journal Bone (doi: 10.1016/j.bone.2026.118014)
About the Complexity Science Hub (CSH)
The Complexity Science Hub (CSH) is Europe's research center for the study of complex systems. Drawing on large-scale data across economics, medicine, ecology, and the social sciences, CSH develops quantitative methods to understand the interconnected networks that underlie society – from financial markets and supply chains to public health and urban development. The goal is to provide a rigorous basis for navigating the challenges of an increasingly complex world.
Members of the Complexity Science Hub are: AIT Austrian Institute of Technology, BOKU University, Central European University (CEU), IT:U Interdisciplinary Transformation University Austria, Medical University Vienna, TU Wien, TU Graz, University for Continuing Education Krems, Vetmeduni, WU Vienna and WKO.
About the Ludwig Boltzmann Gesellschaft (LBG)
The Ludwig Boltzmann Gesellschaft (LBG) is a non-university research and research funding organisation with a focus on "Science for Society". Its thematic priorities lie primarily in the fields of medicine and the life sciences as well as the humanities, social and cultural sciences. Together with academic partners and partners from practice, the LBG operates Ludwig Boltzmann Institutes (LBI) and develops and pilots new forms of collaboration between science and non-scientific actors such as civil society, businesses and the public sector. With its Clinical Research Groups (CRG) funding programme, the LBG offers Austria's first funding line for non-commercial, disease- and patient-oriented (translational), consortium-based clinical research. The LBG comprises the LBG Open Innovation in Science Center, which unlocks the potential of open innovation for science, and the LBG Career Center, which supports early-career researchers in achieving their individual career goals within or outside academia.
