For almost a decade, the MrMs. Os Hong Kong cohort study has been examining the risk factors of fragility fractures in 4,000 men and women.
Hong Kong faces an increasing burden from osteoporosis and hip fragility fractures. Although the age adjusted hip fracture risk in Hong Kong is declining slightly, this is outweighed by the growing older population.1 The average life expectancy in Hong Kong is among the highest in the world (81.9 years for men, and 87.6 years for women).2,3 Projections suggest that by 2036, 31.1% of the population will be more than 65 years of age.4 However, the ageing population will lead to a substantial increase in annual fragility fracture incidence.1
Out of all fragility fractures, hip fracture carries the highest health and social care costs. In 2018, direct hip fracture costs to public hospitals in Hong Kong were approximately USD12,700 (~€11,596).
The indirect costs for a hip fracture have not been estimated in Hong Kong. However in neighbouring Taiwan, the estimated annual indirect costs were USD1,760, 480 or 1,240 per patient if discharged to nursing home, foreign-paid home-care or domestic-paid home-care, respectively.5 In a large local survey of hip fracture patients in 2012, Leung et al. found that 23% of hip fracture patients were discharged to an old-age home for the first time.6 Disappointingly, only 23% of hip fracture patients were prescribed anti-osteoporosis medications on discharge and 4% had another fragility fracture within one year.6 This highlighted the inadequacy of secondary prevention in public hospitals in Hong Kong. The public health system in Hong Kong does not fund anti-osteoporosis medications except for secondary prevention in existing patients in specialist outpatient clinics and there is limited access to Dual-energy x-ray absorptiometry (DXA) scan.
Osteoporosis was previously defined by the incidence of osteoporotic fracture (i.e. hip, vertebral and wrist). In recent years, DXA, a measure of bone mineral density (BMD) at hip and lumbar spine, has used to define osteoporosis, and low hip BMD (femoral neck) measured by DXA, is widely used in treatment guidelines to define osteoporosis and set drug-treatment thresholds.7 European and North American studies demonstrate that DXA screening followed by osteoporosis drug treatment in older people can substantially reduce hip fracture rates by 25–50% in less than five years, and the cost effectiveness of this approach has been demonstrated in older men and women in many countries.8-11
Risk factors of fragility fractures
Since 2001, we have been conducting a prospective cohort study of 4,000 men and women aged above 65 years in Hong Kong (MrMs. Os Hong Kong cohort study) to examine the risk factors of fragility fractures. Our data has contributed to the set up and evaluation of Fracture Risk Assessment Tool (FRAX) by the International Osteoporosis Foundation, which seeks to improve the predictive value of BMD by incorporating clinical risk factors.12 Since then, FRAX has been widely used to guide intervention in local and international osteoporosis treatment guidelines.13,14 Country-specific FRAX use was recommended by the 2019 European guidelines to assess risk in post-menopausal women, including BMD in intermediate-risk individuals.15 Based on our cohort study, we have demonstrated that the strategy of universal DXA and treating patients with Fracture Risk Assessment Tool (FRAX) was cost-effective.13 Moreover, we have found that trabecular bone score (TBS), a qualitative measure of bone microarchitecture of lumbar spine based on DXA images, had additive value to FRAX in predicting hip fracture incidence in older men but not in older women.16 We also found that history of fall in the previous year had predictive value for fracture independently of FRAX.17
Despite the evidence for the effectiveness and cost effectiveness of DXA screening and drug treatment for osteoporosis in preventing hip fractures, the take-up rates for DXA screening and osteoporosis drugs are low in most older populations, especially in Hong Kong where primary prevention is not public funded. Shepstone it et al. showed by a large randomised controlled trial that FRAX questionnaire (without BMD measurement by DXA) posted to women 70–85 years in a randomised trial in the UK, resulted in significant increase in the use of DXA and osteoporosis drug treatment and a very significant 28% hip fracture reduction over five years.18 Based on our cohort study data, we demonstrated that FRAX questionnaire when combined with a five item questionnaire for sarcopenia (SARC-F) could identify more than 75% of older people who would have an incident hip fracture within 10 years.12 It is important to point out that other than drug treatment, lifestyle measures, including a balanced diet rich in calcium and vitamin D, regular exercise, avoidance of smoking or excessive alcohol intake, and adequate sunlight exposure are important measures to prevent osteoporosis and fractures.13
Hip fractures in older people is preventable
Moreover, it is important to consider that hip fractures almost always result from a fall. Due to ageing of muscles, vision and balance control, older adults are more likely to experience falls than younger counterparts.19 Unsurprisingly, fall history is a risk factor for subsequent falls and an independent predictor of fracture in older men and women.17,20-23 Older people with a fall should therefore be offered a comprehensive fall risk assessment. DXA screening in these high-risk individuals is also recommended. A history of a fall is a good reason for fall risk and DXA assessments, but these assessments should not be confined with those with a history of fall. Guidelines from the American Geriatrics Society and the British Geriatrics Society recommend annual screening of all community-dwelling older people aged over 65 years for falls and risk of falling.24
A meta-analysis of 159 trials in over 79,000 community-dwelling patients, including diverse fall-risk reduction strategies, found group or home-based exercise programmes, including Tai Chi and home modifications, can reduce fall risk and fall-related fracture.25 In a local randomised controlled trial of older fallers, a home visit and home-modification by an occupational therapist was effectively lowered the incidence of further fall(s) in the following year, compared with controls (13.7% vs 20.4%).26
In conclusion, hip fracture in older people is preventable. There is a strong case for active screening for osteoporosis and fall risk in older people. Together with public education for healthy lifestyle and fall prevention, exercise interventions and anti-osteoporosis drugs in at risk individuals, there is every hope that the rising incidence of hip fracture in Hong Kong and elsewhere can be controlled.
References
1 Man, L.P., Ho, A.W., and Wong, S.H. 2016. Excess mortality for operated geriatric hip fracture in Hong Kong. Hong Kong Med J. 2016;22(1):6-10. doi:10.12809/hkmj154568
2 The World Bank. 2019. World Development Indicators. https://datacatalog.worldbank.org/dataset/world-development-indicators. Accessed March 18, 2019
3 Healthy HK (Department of Health, Government of Hong Kong SAR). 2019. HealthyHK – Public Health Information and Statistics of Hong Kong – Life Expectancy. https://www.healthyhk.gov.hk/phisweb/en/healthy_facts/health_indicators/life_exp/. Accessed December 3, 2019
4 Hong Kong Special Administrative Region, Census and Statistics Department. 2019. Hong Kong Population Projections 2017–2066. Available at: https://www.statistics.gov.hk/pub/B1120015072017XXXXB0100.pdf. Accessed 1 December 2019. Accessed September 2, 2019.
5 Chan, D.C., McCloskey, E.V., and Chang, C.B. et al. 2017. Establishing and evaluating FRAX® probability thresholds in Taiwan. J Formos Med Assoc. 2017;116(3):161-168. doi:10.1016/j.jfma.2016.03.006
6 Leung, K.S., Yuen, W.F., and Ngai, W.K. et al. 2017. How well are we managing fragility hip fractures? A narrative report on the review with the attempt to setup a Fragility Fracture Registry in Hong Kong. Hong Kong Med J. 2017;23(3):264-271. doi:10.12809/hkmj166124
7 Curry, S.J., Krist, A.H., and Owens, D.K. et al. 2018. it Screening for Osteoporosis to Prevent Fractures: US Preventive Services Task Force Recommendation Statement. JAMA. 2018;319(24):2521-2531. doi:10.1001/jama.2018.7498
8 Dell, R., and Greene, D. 2010. Is osteoporosis disease management cost effective? Curr Osteoporos Rep. 2010;8(1):49-55. doi:10.1007/s11914-010-0009-0
9 Dell, R., Greene, D., and Schelkun, S.R. et al. 2008. Osteoporosis disease management: the role of the orthopaedic surgeon. J Bone Joint Surg Am. 2008;90 Suppl 4:188-194. doi:10.2106/JBJS.H.00628
10 Newman, E.D., Ayoub, W.T., and Starkey, R.H. et al. 2003. Osteoporosis disease management in a rural health care population: hip fracture reduction and reduced costs in postmenopausal women after 5 years. Osteoporos Int. 2003;14(2):146-151. doi:10.1007/s00198-002-1336-5
11 Nayak, S., and Greenspan, S.L. 2016. Cost-Effectiveness of Osteoporosis Screening Strategies for Men. J Bone Miner Res. 2016;31(6):1189-1199. doi:10.1002/jbmr.2784
12 Su, Y., Woo, J.W., and Kwok, T.C.Y. 2019. The Added Value of SARC-F to Prescreening Using FRAX for Hip Fracture Prevention in Older Community Adults. J Am Med Dir Assoc. 2019;20(1):83-89. doi:10.1016/j.jamda.2018.08.007
13 OSHK Task Group for Formulation of 2013 OSHK Guideline for Clinical Management of Postmenopausal Osteoporosis in Hong Kong, Ip T-P, Cheung S-KW, et al. The Osteoporosis Society of Hong Kong (OSHK): 2013 OSHK guideline for clinical management of postmenopausal osteoporosis in Hong Kong. Hong Kong Med J. 2013;19 Suppl 2:1-40.
14 Kanis, J.A., Harvey, N.C., and Cooper, C. et al. 2016. A systematic review of intervention thresholds based on FRAX : A report prepared for the National Osteoporosis Guideline Group and the International Osteoporosis Foundation. Arch Osteoporos. 2016;11(1):25. doi:10.1007/s11657-016-0278-z
15 Kanis, J.A., Cooper, C., and Rizzoli, R. et al. 2019. European guidance for the diagnosis and management of osteoporosis in postmenopausal women. Osteoporos Int. 2019;30(1):3-44. doi:10.1007/s00198-018-4704-5
16 Su, Y., Leung, J., and Hans, D. et al. 2017. The added value of trabecular bone score to FRAX to predict major osteoporotic fractures for clinical use in Chinese older people: the Mr. OS and Ms. OS cohort study in Hong Kong. Osteoporos Int. 2017 Jan;28(1):111-117. doi: 10.1007/s00198-016-3741-1
17 Su, Y., Leung, J. and Kwok, T. 2017. The role of previous falls in major osteoporotic fracture prediction conjunction with FRAX in older Chinese men and women: the Mr. OS and Ms. OS cohort study in Hong Kong. Osteoporos Int. 2017 Oct 24. doi: 10.1007/s00198-017-4277-8
18 Shepstone, L., Lenaghan, E., and Cooper, C. et al. 2018. Screening in the community to reduce fractures in older women (SCOOP): a randomised controlled trial. Lancet. 2018;391(10122):741-747. doi:10.1016/S0140-6736(17)32640-5
19 Guerado, E., Sandalio, R.M., and Caracuel, Z. et al. 2016. Understanding the pathogenesis of hip fracture in the elderly, osteoporotic theory is not reflected in the outcome of prevention programmes. World J Orthop. 2016;7(4):218-228. doi:10.5312/wjo.v7.i4.218
20 Scott, V., Votova, K., and Scanlan, A. et al., 2007. Multifactorial and functional mobility assessment tools for fall risk among older adults in community, home-support, long-term and acute care settings. Age Ageing. 2007;36(2):130-139. doi:10.1093/ageing/afl165
21 Wu, T.Y., Chie, W.C., and Yang, R.S. et al. 2013. Risk factors for single and recurrent falls: a prospective study of falls in community dwelling seniors without cognitive impairment. Prev Med. 2013;57(5):511-517. doi:10.1016/j.ypmed.2013.07.012
22 Woo, J., Leung, J., and Wong, S. et al. 2009. Development of a simple scoring tool in the primary care setting for prediction of recurrent falls in men and women aged 65 years and over living in the community. J Clin Nurs. 2009;18(7):1038-1048. doi:10.1111/j.1365-2702.2008.02591.x
23 Harvey, N.C., Odén, A., and Orwoll, E. et al. 2018. Falls Predict Fractures Independently of FRAX Probability: A Meta-Analysis of the Osteoporotic Fractures in Men (MrOS) Study. J Bone Miner Res. 2018;33(3):510-516. doi:10.1002/jbmr.3331
24 Panel on Prevention of Falls in Older Persons., American Geriatrics Society., and British Geriatrics Society. 2011. Summary of the Updated American Geriatrics Society/British Geriatrics Society clinical practice guideline for prevention of falls in older persons. J Am Geriatr Soc. 2011;59(1):148-157. doi:10.1111/j.1532-5415.2010.03234.x
25 Gillespie, L.D., Robertson, M.C., and Gillespie, W.J. et al. 2012. Interventions for preventing falls in older people living in the community. Cochrane Database Syst Rev. 2012;(9):CD007146. doi:10.1002/14651858.CD007146.pub3
26 Chu, M.M.L., Fong, K.N.K., and Lit, A.C.H. et al. 2017. An Occupational Therapy Fall Reduction Home Visit Program for Community-Dwelling Older Adults in Hong Kong After an Emergency Department Visit for a Fall. J Am Geriatr Soc. 2017;65(2):364-372. doi:10.1111/jgs.14527
Professor Timothy Kwok
The Chinese University of Hong Kong
+852 3505 3145
tkwok@cuhk.edu.hk
www.jococ.org/en/
Please note, this article will also appear in the first edition of our brand new quarterly publication. Subscribe here for all the exciting news updates.
