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November 2022   |   Volume 24 No. 1

Fractured Vision

A massive international study of hip fracture – one of the most common ailments affecting the elderly – has provided both a better understanding of the impact of demographic variation on osteoporosis and support for strategic policymaking in the management of ageing populations.

The project, which is the largest collaborative study of hip fracture ever undertaken and involved 400 million patients, was planned in 2019 and officially started in 2020. The global team of Amgen, a pharmaceutical company which makes anti-osteoporosis medications, invited experts to help estimate the global burden of hip fractures in 19 countries and regions.

HKU was the coordinating centre of the whole study, led by Professor Ian Wong, Lo Shiu Kwan Kan Po Ling Professor in Pharmacy, Dr Ching-Lung Cheung and Dr Chor-Wing Sing from the Department of Pharmacology and Pharmacy, HKUMed.

“The Department’s big data research is world renowned and has been attracting collaborations from the world,” said Professor Wong. “This is not the first time we’ve led a global study on a disease’s epidemiology – we have published several impactful global epidemiology studies, such as the NeuroGEN study in 2018, whose findings helped the world shape clinical guidelines and policy. We believe that our experience and reputation are key to attracting such collaborations.”

Multinational studies are not uncommon for hip fractures but the scale is usually small. “And, while the Global Burden of Disease study (GBD) represents large-scale multinational research,” continued Professor Wong, “it is also a modelling study using mainly reported summary data. Conversely, this study was based on the raw data obtained from large representative databases – for example, electronic medical records, claims databases, and national records – and therefore highly accurate.”

Nineteen countries from across different continents – including Oceania, Asia, Northern and Western Europe and North and South America – were invited to take part to increase the representativeness of the study, with one of the criteria being that they have well-established healthcare databases for analysis. The team members have worked closely with most of the collaborators in previous multinational studies.

Team photo

Dr Ching-Lung Cheung (left), Associate Professor, and Dr Chor-Wing Sing, Research Assistant Professor, of the Department of Pharmacology and Pharmacy, HKUMed.

Secular trend

“We compared the secular trend of hip fracture incidence, one-year mortality after hip fracture, treatment rate after hip fracture, and projected number of hip fractures stratifying by age, sex, and study site,” said Dr Sing. “Our study revealed that the secular trend of the incidence of hip fracture varies and one-year mortality rate after hip fracture across countries and regions, with most of them showing a decreasing trend.

“However, even though the trend is decreasing, this is not enough to offset the effect of the growing ageing population in many countries. We project that the hip fracture counts will likely double by 2050 compared with 2018, while there will be a larger proportional increase in men (vs women) and among people aged 85 years or above (vs other age groups).”

The study also revealed that the use of anti-osteoporosis medication after hip fracture is sub-optimal. “Even though international treatment guidelines recommend the use of anti-osteoporosis medication following hip fracture, we found that the treatment rate after hip fracture is generally far below 50 per cent,” said Dr Sing.

Sex disparity

“There is also an obvious sex disparity in hip fractures,” said Dr Cheung. “Osteoporosis is commonly perceived as a ‘woman’s disease’, and it is largely neglected in men. Men had a smaller decline in hip fracture incidence; higher mortality rate (19.2 per cent to 35.8 per cent in men vs 12.1 per cent to 25.4 per cent in women); and lower treatment rate than women by 30 per cent to 67 per cent across countries and regions. Although the incidence is obviously higher.”

The team concluded that osteoporosis is an under-recognised and under-treated condition. “International experts call it ‘the crisis of the treatment of osteoporosis’,” said Dr Cheung. “Since it is a prevalent disease, together with the expanding global life expectancy, ignoring the importance of osteoporosis will lead to the increased risk of hip fracture. This is not only an issue for the patient, but also for the carers and for society, since hip fractures lead to an increase in healthcare expenditure, use of healthcare resources, dependency, and institutionalisation.

“Moreover, osteoporosis is commonly perceived as a ‘woman’s disease’, that is the reason leading to the sex disparities in the secular trend of incidence of hip fracture. Similarly, the increase in the secular trend of incidence of hip fracture among the oldest old is also the highest compared with other age groups.”

Having completed such a comprehensive study, the team is now calling for action in preventing hip fracture. “For example, by strengthening the current hip fracture programme including education, treatment, and fall prevention,” said Professor Wong. “We further advocate considering other useful approaches that have been shown to reduce the risk of hip fracture, such as community screening for osteoporosis. A special focus on men and the oldest old should be emphasised, since these groups of people have shown the highest increase in the incidence of hip fracture in recent years.”

This study was based on the raw data obtained from large representative databases – for example, electronic medical records, claims databases, and national records – and therefore highly accurate.