Fracture risk assessment

Norwich, John A Kanis

SCOOP Launch, November 07

03ca011

Common sites of fracture

Spine

Hip

Wrist

Definition

a systemic skeletal diseasecharacterised by low bone mass

and microarchitecturaldeterioration of bone tissue,with a consequent increase

in bone fragility andsusceptibility to

fracture

Consensus Development Conference, 1993

03 Osteoporosis

-4 -3 -2 -1 0 1 2 3 4

Bone mineral density (SD units or T-score)

Osteoporosis Low bone Normal

0.6 15 50 85 >99

Percent of population

mass

Diagnostic thresholds for women99ca160 ex94ca117 from 91ca129

- Presence of strong risk factors

oestrogen deficiency

corticosteroid therapy (>7.5 mg >1 year)

maternal history of hip fracture

low BMI (<19 kg/m )

- Radiographic osteopenia

- Previous fragility fracture

- Height loss/ thoracic kyphosis (after radiography)

Indications for the diagnostic use of BMD

99ca021

04ca226Case finding strategies

CRFs

BMD

T-score< -2.5

Treat

Age >65y?

yes

CRFs

yes no

BMDBMD

T-score < -1.5

Treat

T-score < -2.0

Treat

IOF NOF

05ca085

Osteoporotic fracture and BMD

Fractures/1,000 person-years Number of fractures

1.0 0.5 0.0 -0.5 -1.0 -1.5 -2.0 -2.5 -3.0 -3.5

Fracture rate

Women with fractures

0

10

20

30

40

50

0

100

200

300

400

Siris. Surgeon General’s Workshop on Osteoporosis and Bone Health, December 2002

T-score (SD)

-3 -2 -1 0 10

10

20

Fracture probability (%)

50

60

70

80

Age (years) Women

Ten year probability of hip fracture in Sweden

00ca104

04ca148rev Assessment of osteoporosis at primary health care level

Objectives

- to optimise sensitivity for fracture risk

prediction

- case finding or screening strategy

- men and women

- cost-effective setting

- international validity

- suitable for primary care

• Validated in multiple populations

• Data for age, sex and type of fracture

• Readily assessable by primary care practitioners

• Be intuitive rather than counterintuitive to medical

care.

• Contribute to a risk that is amenable to the therapeutic

manipulation intended

Risk factors03ca175

04ca130Cohorts studied

CaMoS

Rotterdam

EVOS / EPOS

Rochester

Kuopio

Hiroshima

Sheffield

Gothenburg I Gothenberg II

DubboEPIDOS OFELY

n = 59,232 person-years = 249,898 % female = 74

Any fracture = 5,444 osteoporotic fractures = 3,495 hip fractures = 957

04ca138

0

1

2

3

4

5

50 55 60 65 70 75 80 85

Age (years)

Men and women

RR/SD

Femoral neck BMD and hip fracture prediction

05ca186 Prior fracture and hip fracture risk

0

2

4

6

50 55 60 65 70 75 80 85

Age (years)

RR

07ca080 BMI and fracture risk

0.0

1.0

2.0

3.0

Osteoporotic fracture Hip fracture

RR (20 v 25 kg/m2)

Without BMD

With BMD

04ca248 Risk factors for hip fracture in men and women

0.0

1.0

2.0

3.0

RR

Without BMD With BMD

Priorfracture

FH(hip)

Smokingcurrent

Alcohol>2u

Steroidsever

RA

10-year probability of hip fracture in Malmo

99ca094

0

5

10

15

20

Age (years)

Probability (%)

women

50 60 70 80 90

men

Age (years)50 55 60 65 70 75 80 85

0

10

20

30

40

50

60

70

10 year risk (%)

1.02.0

3.04.0

5.06.0

RR

Ten year probability of hip fracture - Swedish women

01ca048

06ca106 FRAX

Patient

65

65

165

-2.5

23.9

8.0

24

04ca014 Clinical risk factors and fracture probability

0

2

4

6

NoneSm

oking

Alcohol

2 o osteoporosis

FH Steroids

Prior Fx

10 year hip fracture probability (%)

Mrs X

Age = 65 y

Height =161cm

Weight = 61kg

BMI = 23.5 kg/m2

05ca106

0

10

20

30

40

50

60

70

0 -1 -2 -3

T-score

0 -1 -2 -3

NonePrior fracture+Glucocorticoids+Family history

Men Women

US Caucasian, no CRF, BMI=24 *Hip, spine, humerus, forearm

Probability of osteoporotic fracture* at age 65

10-year probability (%)

05ca092Case finding strategies

CRFs

Fractureprobability

High

Treat

Intermediate Low

BMD

Reassessprobability

High Low

Treat

05ca200Stratification of hip fracture

risk

No

NoNo

Woman aged 65, BMI=24

Yes

YesYes

YesNoYesNo Yes NoYesNo

3.7 12.93.1 5.46.42.67.51.5

Rheumatoid arthritis

Glucocorticoids

Prior fracture

10-year hip fractureprobability (%)

07ca027Gradient of risk for hip fracture prediction

1

2

3

4

5

6

RR/SD

50 60 70 80 90 50 60 70 80 90 50 60 70 80 90

Age (years)

CRFs BMD CRFs+BMD

07ca030 Gradient of risk and fracture prediction

0

2

4

6

8

10

-4 -3 -2 -1 0 1 2 3 4

Risk ratio (vs. general population)

GR=2.6

GR=1.6

Z-score

% 50.0100.0 97.799.9 84.1 15.9 2.3 0.1 0.0

4.93.5Mean RR

5.00.5% Population

1.632.57Z-score

2.61.6GR

NorwayIceland

Singapore USACanada

Germany UK ItalyKuwait Spain

Portugal

China (HK)

VenezuelaTurkey Chile0

0.2

0.4

0.6

0.8

1.0

1.2

Relative probability

Sweden

Denmark

China (TW)

Switzerland

Australia

Netherlands

Finland

Greece

Argentina

Hungary

JapanFrance

China

Korea

Very high High Moderate Low risk

Ten year probability of hip fracture compared with Sweden

01ca025

00ca008

End

04ca191Identification of reversible risk

a. Risk amenable to intervention

Low BMD

Previous fracture

Use of glucocorticoids

b. Presence of risk factor does adversely affect therapeutic response

Age

Body mass index

Family history of fracture

Smoking and alcohol

Markers of bone turnover

c. Uncertain effects

Neuromuscular incompetence

Liability to falling