Screening to Prevent Fractures

Introduction and research questions: Hip fractures and other major fractures pose significant threats to the health and independence of older adults and incur high healthcare costs. Various methods are available to assess fracture risk, including risk factors, bone density, and vertebral fracture assessments. However, these resources are primarily used after a fracture occurs. Since two-thirds of people with a new fracture have never had one, we aimed to investigate whether screening could prevent further fractures. Chapters 2 through 6 address this question. Osteoporosis can sometimes be secondary to underlying conditions, therfore routine lab tests are often conducted in individuals with osteoporosis or fractures. Chapters 7 and 8 assess the value of routine blood tests for managing osteoporosis and fractures in primary care. The third research question arises from the recommendation for all women over 50 to take vitamin D supplements. Not all women have low vitamin D levels, and unnecessary supplementation may occur. Chapter 9 investigates whether vitamin D deficiency can be predicted in older women. Chapter 2 compares various fracture risk selection models in nine GP practices. Chapter 3 and 4 the describe the SALT Osteoporosis Study (SOS), a randomized trial with 3 years of follow-up. The purpose of SOS was to assess whether screening for increased fracture risk in older women and subsequent treatment according to osteoporosis guidelines reduces fractures compared to usual care. This study included 11,032 women from 217 GP practices. The screening program did not significantly reduce fractures, osteoporotic fractures, or mortality. However, in a post-hoc analysis of women with recent fractures, screening led to a 35% reduction in major osteoporotic fractures and a 62% reduction in hip fractures. Chapter 5 presents a meta-analysis of three large randomized fracture risk screening studies, including SOS, with 42,009 participants in total. The intervention group showed a significant reduction in osteoporotic fractures(5%), major osteoporotic fractures(9%), and hip fractures(20%). There was no effect on mortality. Chapter 6 discusses the current fracture prevention guidelines. We conclude that Fracture Liaison Services(FLS) for individuals under 65 are likely ineffective, as there is insufficient evidence for fracture reduction in this age group and a low absolute hip fracture risk under 70. Screening for fracture risk in older women could complement FLS, as most new fractures are first fractures. Chapter 7 investigates the prevalence of laboratory abnormalities(e.g., vitamin D, calcium, creatinine) in the SOS population. Vitamin D deficiency(<30 nmol/L) was found in 13%, while other abnormalities occurred in 4.6%. 82% of these abnormalities had no clinical impact. There was a weak association between laboratory abnormalities and low bone mineral density(BMD). Chapter 8 examines similar laboratory tests in men and women with recent fractures referred for fracture risk evaluation. Vitamin D deficiency was present in 10.4%, and other abnormalities in 5.2%. Abnormalities were associated with older age, low BMD, vertebral fractures, and recent hip fractures. Chapter 9 describes models to predict low serum 25(OH)vitamin D. The best model(threshold of 30 nmol/L) used variables such as age, BMI, supplementation, and lifestyle. The model performed with an AUC of 0.77. Conclusions: Screening for increased fracture risk leads to a reduction in hip and other osteoporotic fractures. Future research should focus on optimizing screening implementation, cost-effectiveness, and increasing support from healthcare providers. A reserved approach to routine laboratory testing for secondary osteoporosis is appropriate in older women without recent fractures. Laboratory testing should be considered for women with a recent fracture that require anti-osteoporosis medication. Supplementation or measurement of vitamin D is indicated after a recent fracture. In older women without fractures a prediction tool may help to differentiate whether suppletion of vitamin D is necessary.