ST05_Mar12

Normative values for the Bath Ankylosing Spondylitis

Metrology Index (BASMI)

Lucy Chilton-Mitchell1

Anna Hart, 2 Jane Martindale, 1,2 Lynne Goodacre3

1 Wrightington Wigan and Leigh NHS Foundation Trust, 2 Lancaster University, 3 R and D North West

Outline

• Background to study

• Methodology

• Results

• Discussion and implications for practice

• Limitations of study

• Future work

• Key messages

• Background• Methodology• Results• Discussion• Future Work• Key messages

Spinal mobility in AS

• Natural history of AS‘Progressive restriction in spinal mobility’1

• Background• Methodology• Results• Discussion• Future Work• Key messages

• Google image search

‘ Ankylosing Spondylitis and age’

Assessment of spinal mobility in AS • Background• Methodology• Results• Discussion• Future Work• Key messages• Loss of spinal mobility important clinical sign

- Modified NY criteria2

- ASAS core domain3

• Recommended measure of spinal mobility (ASAS) – BASMI3

• Spinal mobility- Obtain baseline measurement4

- Monitor change over time4

- Assess the impact of clinical interventions3

BASMI scoring systems

BASMI 2 scoring system(4)

BASMI 10 scoring system(5)

BASMI linear scoring system(6)

• Background• Methodology• Results• Discussion• Future Work• Key messages

BASMI10

Are we correct to expect a score of zero is representative of normal spinal movement in a healthy population?

• Background• Methodology• Results• Discussion• Future Work• Key messages

0 = No mobility limitation

10 = Severe mobility limitation

Work informing this study

• Inter- and intra-rater reliability of BASMI7

• Incidental finding– Some healthy volunteers had worse BASMI scores than AS

patients– 7 healthy volunteers– BASMI scores ranged 0.7-2.0– Mean BASMI score 1.3

This study suggests that a score of zero should not be expected in a healthy population

• Background• Methodology• Results• Discussion• Future Work• Key messages

Spinal changes with age • Background• Methodology• Results• Discussion• Future Work• Key messages

• Google image search

‘ Spinal posture and age’

Literature on ageing….

If spinal ROM decreases with increasing age, should we expect the BASMI to increase with age also?

• Background• Methodology• Results• Discussion• Future Work• Key messagesYoudas et al8

Chen et al9

Finnsback et al10

Moll & Wright11

Saidu et al12

Einkauf et al13

Fitzgerald et al14

Intolo et al15

Aim

To explore the normative values for total BASMI score in healthy men and women

in a UK population

• Background• Methodology• Results• Discussion• Future Work• Key messages

Methodology

• Cross-sectional study

• 168 participants recruited - UK population

• Stratified by gender and age

• 14 Physiotherapists involved in recruiting and measuring participants

• ASSIGNw consensus of measurement for each domain was followed 7

• Exclusion criteria:– Pregnancy– Diagnosis of AS/Axial SpA,– Acute back problems– Chronic back problems,– Impairment limiting normal movement at time of measurement

Age range 18-30 30-50 50 and over

Gender Male Female Male Female Male Female

Number 2 2 2 2 2 2

• Background• Methodology• Results• Discussion• Future Work• Key messages

Statistical analysis

• Descriptive statistics were obtained:– Therapist experience– Total BASMI scores– BASMI component scores– Percentage scoring zero on the BASMI

• Age-specific centiles were calculated16

- Centiles presented start at age 25 and increase in 10 year intervals

• Background• Methodology• Results• Discussion• Future Work• Key messages

Results

• 168 participants (age range 18-85)

- Males = 84, Females= 84

- 18-30 = 56, 30-50 = 56, 50+= 56

• BASMI scores: 0 – 4.4

• 1.2% individuals scored 0

• BASMI scores increased with increasing age

• Corresponding trends with BASMI component scores

• No gender differences

• Background• Methodology• Results• Discussion• Future Work• Key messages

Total BASMI score

<30 years 30-50 years >= 50 years

M F M & F M F M & F M F M & F

Total BASMI score

0.8 0.8 0.8 1.0 1.4 1.2 2.2 1.6 2.0

• Zero is not a ‘normal’ score for an individual from a healthy population

• Increase in total BASMI score with increasing age

• Background• Methodology• Results• Discussion• Future Work• Key messages

Modified Schober’s Test

< 30 years 30-50 years >= 50 years

M F M & F M F M & F M F M & F

Modified Schober’s

(cm)6.5 6.6 6.5 6 6 6 5.5 6 6

Modified Schober’s

BASMI score1 1 1 2 2 2 3 2 2

• Decrease in Modified Schober’s test with increasing age

• Corresponding increase in component BASMI score

• Background• Methodology• Results• Discussion• Future Work• Key messages

Intermalleolar Distance

< 30 years 30-50 years >= 50 years

M F M & F M F M & F M F M & F

IMD (cm)110 117 115 113 107.5 112 95 104 102

IMD BASMI score 1 1 1 1 2 1 3 2 2

• Decrease in intermalleolar distance with age

• Corresponding increase in component BASMI score

• Background• Methodology• Results• Discussion• Future Work• Key messages

Cervical Rotation

< 30 years 30-50 years >= 50 years

M F M & F M F M & F M F M & F

Cx rotation (deg) 86 82.5 85 81.5 82.8 82 70.0 76.8 73.8

Cx rotation BASMI score 0 1 0 1 1 1 2 1.5 2

• Decrease in cervical rotation with age

• Corresponding increase in component BASMI score

• Background• Methodology• Results• Discussion• Future Work• Key messages

Tragus-to-wall distance

< 30 years 30-50 years >= 50 years

M F M & F M F M & F M F M & F

Tragus-to-wall (cm) 10.6 10.0 10.3 10.5 10.3 10.5 12.6 10.2 11.5

Tragus-to-wall BASMI

score1 1 1 1 1 1 1 1 1

• Small increase in tragus-to-wall distance with age

• No change in component BASMI score

• Suggests this measure is disease specific

• Background• Methodology• Results• Discussion• Future Work• Key messages

Lumbar side flexion

< 30 years 30-50 years >= 50 years

M F M & F M F M & F M F M & F

Lx lateral flexion (cm) 21.7 21.5 21.5 20.3 19.8 20.0 14.8 16.5 15.8

Lx lateral flexion

BASMI score

0 0 0 0 1 1 3 2 3

• Decrease in lumbar side flexion with age

• Corresponding increase in component BASMI score

• Background• Methodology• Results• Discussion• Future Work• Key messages

Centiles of total BASMI score• Background• Methodology• Results• Discussion• Future Work• Key messages

01

23

45

20 40 60 80 100Age

Total BASMI Score C_1_5C_1_25 C_1_50C_1_75 C_1_95

Centiles of total BASMI score• Background• Methodology• Results• Discussion• Future Work• Key messages

01

23

45

20 40 60 80 100Age

Total BASMI Score C_1_5C_1_25 C_1_50C_1_75 C_1_95

Implications for practice

• Illustrate to patients what a ‘normal’

age-matched individual would score on

the BASMI- Important in newly diagnosed- Inform expectations about treatment effects

• Potentially accounts for influence of age- Not just disease process- Important when assessing change over time

• Background• Methodology• Results• Discussion• Future Work• Key messages

Limitations of study

• Measurements taken by a number of different

therapists

• UK population only

• Sample size

• Did not account for factors such as height17, activity level etc.

• Background• Methodology• Results• Discussion• Future Work• Key messages

Future work

• Larger sample size

• Assess height, weight, activity level

• UK and other populations

• Background• Methodology• Results• Discussion• Future Work• Key messages

Key ‘take-home’ messages

• A total BASMI score of zero is not normal

in the healthy adult population

• The BASMI score increases with age in healthy individuals

• The normative values shown will aid interpretation of BASMI scores in individuals with AS/ Axial SpA

• Background• Methodology• Results• Discussion• Future Work• Key messages

Acknowledgements

• Supervisory team – Dr Jane Martindale and Dr Lynne Goodacre

• Anna Hart (medical statistician)

• WWL (especially CEO and Physiotherapy Lead)

• Lancaster Medical School, Lancaster University

• ASSIGNw volunteers

• Our ‘normal’ participants!

• NIHR

References

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2) van der Linden S, Valkenburg HA, Cats A. Evaluation of diagnostic criteria for ankylosing spondylitis: a proposal for modification of the New York criteria. Arthritis Rheum 1984;27: 361-368

3) Sieper J, Rudwaleit M, Baraliakos X, et al. The Assessment of SpondyloArthritis international Society (ASAS) handbook: a guide to assess spondyloarthritis. Ann Rheum Dis 2009;68:1-44

4) Jenkinson TR, Mallorie PA, Whitelock H, et al. Defining spinal mobility in ankylosing spondylitis: The Bath Ankylosing Spondylitis Metrology Index. J Rheumatol 1994;21:1694-1698

5) Jones SD, Porter J, Garrett SL, et al. A new scoring system for the Bath Ankylosing Spondylitis Metrology Index (BASMI). J Rheumatolo 1995;22:1609

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8) Youdas JW, Garrett TR, Suman VJ, et al. Normal range of motion of the cervical spine: An initial goniometric study. Phys Ther 1992;72:770-780

9) Chen J, Solinger AB, Poncet JF, Lantz CA. Meta-analysis of normative cervical motion. Spine 1999;24:1571-157810) Finnsback C, Mannerkorpi K. Spinal and thoracic mobility – age-related reference values for healthy men and women.

Nordisk Fysioterapi 2005;9:136-143 11) Moll JM, Wright V. Normal range of spinal mobility. An objective clinical study. Ann Rheum Dis 1971;30:381-38612) Saidu IA, Maduagwu SM, Abbas AD, Adetunji OO, Jajere AM. Lumbar spinal mobility changes among adults with

advancing age. J Midlife Health 2011;2:65-7113) Einkauf DK, Gohdes ML, Jensen GM et al. Changes in spinal mobility with increasing age in women. Physical Therapy

1987; 67: 370-37514) Fitzgerald GK, Wynveen KJ, Rheault W et al. Objective assessment with establishment of normal values for lumbar

spinal range of motion. Physical Therapy 1983; 63: 1776-168115) Intolo P, Milosavljevic S, Baxter DG, Carman AB, Pal P. The effect of age on lumbar range of motion: A systematic

review. Man Ther 2009;14:596-60416) Royston P, Wright E M. A method for estimating age-specific reference intervals (‘normal ranges’) based on fractional

polynomials and exponential transformation. J.R. Statistic 1998; Soc. A; 161, Part 1, pp79-101.17) Ramiro S, van Tubergen A, Stolwijk C et al. Reference intervals of spinal mobility measures in normal individuals: the

mobility study. Annals of the Rheumatic Diseases. Published online 2014 doi: 10.1136/annrheumdis-2013-204953

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Chilton-Mitchell L, Martindale J, Hart A, Goodacre L. Normative values for the Bath Ankylosing Spondylitis Metrology Index in a UK population. Rheumatology 2013 52 (11)

2086-2090