Falls and Fracture in the Elderly Tuan V

Falls and Fracture in the Elderly Tuan V. Nguyen Bone and Mineral Research Program Garvan Institute of Medical Research

Overview • Osteoporosis • Magnitude of the problem • Bone mineral density (BMD) and fracture • Falls: etiology and risk factors • Fracture and fall

Osteoporosis: shift in thinking Low bone mass, microarchitectural deterioration of bone tissue leading to enhanced bone fragility and a consequent increase in fracture risk (Consensus Development Conference, 1991) “[…] compromised bone strength predisposing a person to an increased risk of fracture. Bone strength primarily reflects the integration of bone density and bone quality” (NIH Consensus Development Panel on Osteoporosis JAMA 285: 785 -95; 2001)

Osteoporosis in risk-and-outcome view RISK FACTOR OUTCOME Osteoporosis Bone Strength Fracture Bone Quality and Bone Mineral Density Architecture Turnover rate Damage accumulation Degree of mineralization Properties of the collagen/mineral matrix

Normal vs osteoporosis

Breaking bones

Incidence of all-limb fractures

Increase in life expectancy WHO. Human Population: Fundamentals of Growth World Health, 2000.

The ageing of population Percent of population aged 65+ ABS and US Bureau of Census, 1996.

Annual fracture incidence in Australia 1996 -2051 Projected annual number of all-limb fractures in Australia aged 35+ (Sanders et al, MJA 1999)

Hip, vertebrae, and Colles fractures Fracture 2006 2051 Hip 20, 700 60, 000 Vertebrae 14, 500 31, 700 Colles 11, 900 23, 000 Humerus 7, 500 16, 300 Pelvis 4, 100 9, 800 Projected annual number of all-limb fractures in Australia aged 35+(Sanders et al, MJA 1999)

Lifetime risk of some diseases - women Any osteoporotic fracture Hip fracture Clinical vertebral fracture Cancer (any site)* Breast cancer* Lung/bronchus* Coronary heart diseases Diabetes Mellitus *, from birth (from the age of 50)

Lifetime risk of some diseases - men Any osteoporotic fracture Hip fracture Clinical vertebral fracture Cancer (any site)* Prostate cancer* Lung/bronchus* Coronary heart diseases Diabetes Mellitus *, from birth (from the age of 50)

Consequences of fracture • Reduced mortality • Increased morbidity • Reduced quality of life • Incurred significant health care costs

Survival probability with and without fracture Source: Nguyen et al, 2005

Risk of death from hip fracture 50 -year old women: Lifetime risk of mortality from: Hip Fracture: 2. 8% Breast Cancer: 2. 8% Endometrial Cancer: 0. 7% Cummings et al. Arch Intern Med 1989; 149: 2445 -8

Impact of hip fractures • • 25% die within 6 months (*) 60% have restricted mobility (*) 25% remain functionally more dependent Cardiac (8%) and pumonary complication (4%) • Transient heart attacks • Non-union and avancular necrosis

Impact of vertebral fractures • Symptomatic fx : Lifetime risk 1/4 women, 1/8 men • Asymptomatic fx prevalence: 20 -30% • • Back pain, functional limitation Rib-against-pelvis (RAP) syndrome Costoiliac impingement syndrome Decrease vital lung capacity

Asymptomatic vertebral fracture increases risk of subsequent fractures 300 m+w 66 V # 29 Fx 44% 234 No V # 37 no fx 54 Fx 180 no fx 23% Pongchaiyakul C et al, J Bone Miner Res

Asymptomatic vertebral fracture increases risk of death 300 m+w 66 V # 20 deaths 30% 234 No V # 46 survived 25 deaths 209 survived 11% Pongchaiyakul C et al, J Bone Miner Res

Impact of wrist fracture • More common in women in their 50 s • Post-traumatic arthritis • Account for 39% of all physical therapy sessions • Reduced daily living activies Melton LJ, J Bone Miner Res 2003

Fracture Prediction

A model for assessing fracture risk Other factors (age, weight, structural factors) Quadriceps weakness Falls # Postural instability Low bone mass Interaction between BMD and fall-related factors in the prediction of hip fracture

BMD and age

Changes in BMD with age Peak bone density Menopause Osteopenia Puberty Osteoporosis Age

BMD and definition of “osteoporosis” Gaussian distribution Constant standard deviation Decrease with advancing age T-scorei = (BMDi – Peak BMD) / SD • Define “osteoporosis” and “osteopenia” T-score < -2. 5 = “osteoporosis” -2. 5 < T-scores < -1 = “osteopenia”

Prevalence of osteoporosis Women Men

Bone mineral density (BMD) and fracture risk T < 2. 5 osteoporosis Source: Dubbo Osteoporosis Epidemiology Study

14 -year predictive value of BMD - women 1287 women Osteoporosis 345 (27%) Fx = 137 (40%) No Fx = 208 (60%) Non-osteoporosis 942 (73%) Fx = 191 (20%) No Fx = 751 (80%) 42% Source: Dubbo Osteoporosis Epidemiology Study

14 -year predictive value of BMD - men 821 men Osteoporosis N = 90 (11%) Fx = 27 (30%) No Fx = 63 (70%) 23% Non-osteoporosis 731 (89%) Fx = 91 (12%) No Fx = 640 (88%) Source: Dubbo Osteoporosis Epidemiology Study

Fracture and BMD: summary of points • BMD is the primary predictor of fracture risk • Less than 50% of fractured individuals have low BMD (eg osteoporosis) • BMD alone does not accurately predict fracture

Falls: etiology and risk factors

Falls • The second leading cause of accidental deaths (Rivara NEJM 1997) • $70 bil health care costs associated with falls and rehabilitation

Incidence of falls in the elderly Source: Dubbo Osteoporosis Epidemiology Study

Incidence of multiple falls in the elderly Source: Dubbo Osteoporosis Epidemiology Study

Why do falls occur ? Extrinsic Factors Intrinsic Factors Medical conditions Impaired vision and hearing Age related changes Medications FALLS Improper use of assistive devices Environment

Etiology of falls • • Accidents / environment 37% Weakness, balance, gait 12% Drop attack 11% Dizziness or vertigo 8% Orthostatic hypotension 5% Acute illness, medications, vision Unknown 8% 18% Rubenstein et al JAGS 1988

Risk factors for falls • Risk Factor – Sedative use – Cognitive Impairment – Lower extremity problem – Pathologic Reflex – Foot Problems – > 3 balance/gait problems – >5 balance/gait problems OR 28 5 4 3 2 1. 4 1. 9 Tinetti NEJM 1988

Measurement of postural sway A non-fracture control A hip fracture case Postural sway test

Predictors of fall risk Variables Unit Women Men Age + 5 y 1. 2 (1. 2, 1. 3) 1. 4 (1. 2, 1. 6) Postural sway + 60 cm 2 1. 2 (1. 1, 1. 4) 1. 3 (1. 1, 1. 5) Quadriceps strength -10 kg 1. 3 (1. 1, 1. 5) Note: Odds ratio and 95% confidence interval Source: Dubbo Osteoporosis Epidemiology Study

Falls and Fractures

Relationship between falls and fractures Falls Fx • 95% of hip fractures are caused by falls (Nyberg L, J Am Geriatr Soc 1996) • Only 5% of falls cause fractures

Falls and fracture risk Source: Dubbo Osteoporosis Epidemiology Study

Fall-related factors and hip fracture risk Source: Nguyen et al, JBMR 2005

Fall-related factors and hip fracture risk BMD-and-gender-adjusted hazards ratio Source: Nguyen et al, JBMR 2005

Fall-related factors and hip fracture risk BMD-independent risk factors for hip fracture Factor Criteria - Age (y) <70 0 > 70 1 No 0 Yes 1 Low 0 High 1 Low 1 High 0 No 0 Yes 1 - Fall in the previous 12 mo - Postural sway (tertile)(*) - Quadriceps strength (tertile)(*) - Prior fracture in the last 5 y (*) gender specific ranges Score Source: Nguyen et al, JBMR 2005

Incidence of hip fracture by FNBMD (T-scores) and number of risk factors Source: Nguyen et al, JBMR 2005

Predictor of fractures in nonosteoporotic men and women Sex Women Men Risk factor(s) Prevalence PARF Age + BMD 0. 92 0. 0 Fall + Sway 0. 08 22. 1 Age + BMD 0. 93 0. 0 Fall + Sway 0. 07 15. 2 PARF: Population attributable risk fraction Source: Dubbo Osteoporosis Epidemiology Study

Can we prevent fracture by reducing falls?

Hip protector

Hip protectors reduced hip fracture risk • Clinical trial: 1801 frail elderly individuals (age: 81 y) in Finland – 78% women – 63% assisted walking • Fracture incidence: 2. 1% vs 4. 6%/yr • 2. 4% of falls resulted in hip fx when not wearing protector vs 0. 4% when wearing protector (80% reduction in risk) • Poor compliance P Kannus et al NEJM 2001

Primary prevention • 301 community dwelling elders with 1+ risk factors for falling • Intervention: adjustment in medications, behavioral instructions, exercise programs aimed at modifying risk factors • One year follow up Tinetti et al. 1994 NEJM

Primary prevention Tinetti et al. 1994 NEJM

Tai Chi reduced falls • Atlanta FICSIT Trial – 200 community dwelling elders 70+ – Intervention: 15 weeks of education, balance training, or Tai Chi – Outcomes at 4 months: Strength, flexibility, CV endurance, composition, IADL, well being, falls • Falls reduced by 47% in Tai Chi group Wolf JAGS 1996

Risk factor modifications for fracture Change Quit smoking Estimated change in fx risk 38% Treat impaired vision 50% Stop sedatives 40% Hip protectors 50%? Cummings et al. Unpublished data

Falls and fractures: summary • Fracture, particularly hip fracture, is a serious public health problem in the elderly • Although low bone mineral density is a primary predictor of fracture risk, it can not account for all fracture cases • Fall is highly prevalent in the community and is a major risk of fracture

Falls and fractures: summary • Risk factors for fall also contribute to fractures • Preventing falls can theoretically reduce fracture incidence • A preventative program is required to reduce falls and fractures

Thank you!