Imminent risk of the first and second recurrent osteoporotic fractures in South Korea.

Background: A history of fractures increases the likelihood of experiencing subsequent and secondary fractures. To prevent further fractures, global guidelines recommend aggressive proactive treatment with medication for patients at an imminent risk of osteoporotic fracture (OF), which is defined as a high likelihood of experiencing subsequent fractures in the near future. However, there is a lack of research focusing on patients with imminent risk of OFs in South Korea. Hence, this study aimed to evaluate the imminent risk of the first and second recurrent OFs among patients with OF in South Korea.

Methods: We conducted a retrospective analysis using the comprehensive Health Insurance Review and Assessment database, which encompasses the entire population of Korea from 2012 to 2017. The study focused on eligible patients aged 55 years and older who experienced an OF in 2013, including fractures in the hip/femur, vertebral, humerus, radius, tibia/fibula, and ankle regions. The first OF occurring in 2013 was considered the index OF. To ensure that the index fracture was the index OFs, we excluded patients who had any OF within 1 year before their index OF. We assessed the incidence of the first recurrent OF within 2 years after the index OF, and the second recurrent OF within 2 years after the occurrence of the first recurrent OF. Additionally, we estimated the risks of experiencing the first and second recurrent OFs according to age and sex using multi-variable Cox proportional hazard regression analysis.

Results: Approximately 17 % of patients with an index OF had the first recurrent OF within 2 years after the index OF. Of those with a first recurrent OF, 28 % experienced a second recurrent OF within 2 years after the first recurrent OF. The two-year incidence rate of the first recurrent OF was 9.6 per 100 person-years (95 % confidence interval [CI], 9.6-9.7). The two-year incidence rate of the second recurrent OF was 22.0 per 100 person-years (95 % CI, 21.6-22.4), which is higher than that of the first recurrent OF. Females had a 31 % higher risk of the first recurrent OF (hazard ratio [HR] = 1.31; 95 % CI, 1.20-1.43) and a 43 % higher risk of the second recurrent OF than males (HR = 1.43; 95 % CI, 1.35-1.51).

Conclusions: In Korea, the imminent risk of a second recurrent OF was higher than that of a first recurrent OF. Consequently, given the elevated risk of subsequent fractures with the number of OFs experienced, a more targeted approach to treatment is recommended for patients with a first recurrent OF considering the risk of subsequent OF.