Calculating and evaluating risk

Calculating the fracture risk

The fracture risk of a patient is calculated by multiplying the weighting factor for each category together. Use the table below to look up the corresponding weighting factor for each risk factor.

For example (seen in the last column of the following table):

  • a person in a hostel with a balance grade of 5 (weighting factor 4.52)
  • and a history of a previous fracture (weighting factor 1.56)
  • has a cognitive function score of 20 (weighting factor 1.41)
  • takes 6 medications (weighting factor 1.00)
  • has a body weight of 48 kg (weighting factor 2.14)
  • and a lower leg length of 51cm (weighting factor 1.27).

The fracture risk for this person is calculated as follows:
4.52 x 1.56 x 1.41 x 1 x 2.14 x 1.27 = 27.02

Using the fracture risk evaluation table, this score puts the person in the highest fracture risk group (>20) with a 23.1% chance of sustaining another fracture.

Category

Variable

Weighting factor

Example

Home type + balance grade)

Intermediate care facility + balance (1–4)

6.31

 

Intermediate care facility + balance (5)

4.52

4.52

Nursing home + balance (2–5)

4.41

 

Nursing home + balance (1)

1.00

 

Previous fracture

Yes

1.56

1.56

No

1.00

 

Cognitive function (SMMSE)

18–23

1.41

1.41

0–17 or 24–30

1.00

 

not known

1.00

 

Number of medications

7 and greater

1.30

 

0–6

1.00

1.00

Body weight (kg)

27–52

2.14

2.14

53–64

1.84

 

65 and greater

1.00

 

Lower leg length (cm)

50.5 and greater

1.27

1.27

less than 50.5

1.00

 

Relative Risk

 

 

27.02

Evaluating the fracture risk

Groups
by Fracture risk

Fracture rate
(per 100 person-years)

1 to 4.999

2.9

5 to 7.999

6.4

8 to 10.999

7.6

11 to 14.999

14.6

15 to 19.999

18.2

20 and greater

23.1