INternational Spondyloarthritis Inter-observer Reliability Exercise –

the INSPIRE study.

Gladman DD, Inman RD, Cook R, Maksymowych W, van der Heijde D,

Lendewé R, Braun J, Davis J, Mease P Brandt J, Burgos-Vargas R, Chandran V,

Helliwell P, Kavanaugh A, Khan MA, O’Shea B, Pipitone N, Rahman P, Reveille JD,

Stone M, Taylor W, Veale D,Supported by SPARCC, the Arthritis Society (Canada), Abbott Canada, Amgen/Wyeth

Canada, Pfizer Canada, Schering Canada, Wyeth Global,

The INSPIRE Study

Several measures have been used in the assessment of ankylosing spondylitis (AS).

It has not yet been determined whether these measurements are reproducible.

It has not been determined whether these measures are applicable in psoriatic arthritis (PsA) with axial involvement.

Background

The INSPIRE study

To determine whether the axial measures used in primary AS were reproducible for both AS and PsA with axial disease

Objective

The INSPIRE Study

Assessors: 20 rheumatologists from 11 countries with expertise in spondyloarthritis (SpA) – 10 experts in AS; 10 experts in PsA

Patients: – 10 patients with PsA with axial involvement – 9 AS patients

Design: A Latin Square design that enabled assessment of patient, assessor and order effect was used.

Measures: occiput to wall, tragus to wall, cervical rotation, chest expansion, lateral spinal bending, modified Schober, and hip mobility.

Analysis: Intra Class Correlations (ICC) adjusted for order of measurements.

Methods

The INSPIRE Study

Patient Characteristics

Group AS PsA

Females/Males 7 / 2 9 / 1

Mean Age (yrs) 38 52

Disease Duration (yrs) 17 16

The INSPIRE Study

Measurement AS PsA with axial disease

Occiput to wallTragus to wallCervical rotation Chest expansion Xiphisternum 4th intercostalModified SchoberLateral spinal bending BASMI Domjan Modified DomjanIntermalleolar distanceInternal Hip rotation

0.81 (0.64,0.94)0.80 (0.63,0.94)0.66 (0.43,0.88)

0.57 (0.33,0.84)0.24 (0.07,0.59)0.85 (0.70,0.95)

0.83 (0.67,0.95)0.91 (0.82,0.98)0.92 (0.83,0.98)0.78 (0.60,0.93)0.92 (0.82,0.98)

0.82 (0.66,0.94)0.67 (0.46,0.88)0.94 (0.87,0.98)

0.64 (0.42,0.87)0.70 (0.50,0.89)0.65 (0.43,0.87)

0.82 (0.66,0.94)0.85 (0.71,0.95)0.77 (0.58,0.92)0.96 (0.91,0.99)0.92 (0.83,0.97)

Spinal Measurements ICC

The INSPIRE Study

% total variance due to

Measure Patient Assessor Order

Occiput to wall

Tragus to wall

81.8 (<0.001)

79.8 (<0.001)

8.0 (0.003)

3.7 (0.66)

0.1 (0.98)

1.9 (0.13)

Cervical rotation 68.1 (<0.001) 14.3 (0.003) 0.1 (0.98)

Chest expansion Xiph*

Chest expansion 4IC*

58.5 (<0.001)

29.3 (<0.001)

26.2 (<0.001)

40.1 (<0.001)

2.5 (0.06)

1.5 (0.56)

Modified Schober 84.9 (<0.001) 5.3 (0.04) 0.7 (0.38)

LLB* – BASMI

LLB – DOMJAN

LLB – INSPIRE

83.3 (<0.001)

91.4 (<0.001)

91.5 (<0.001)

3.9 (0.43)

2.3 (0.24)

1.6 (0.56)

0.4 (0.73)

0.5 (0.30)

1.0 (0.07)

Intermalleolar

Internal Hip rotation

78.4 (<0.001)

91.5 (<0.001)

5.9 (0.19)

2.0 (0.34)

1.2 (0.31)

0.6 (0.24)

Variation in Patients with AS

*LLB=lateral lumbar bending; Xiph=xiphisternum; 4IC=4th intercostal space

The INSPIRE Study

% total variance due to

Measure Patient Assessor Order

Occiput to wall

Tragus to wall

83.0 (<0.001)

68.0 (<0.001)

7.7 (0.001)

10.0 (0.04)

0.1 (0.97)

1.7 (0.24)

Cervical rotation 94.0 (<0.001) 2.8 (0.001) 0.3 (0.20)

Chest expansion Xiph*

Chest expansion 4IC*

66.2 (<0.001)

72.1 (<0.001)

17.3 (<0.001)

15.7 (<0.001)

2.2 (0.10)

0.2 (0.87)

Modified Schober 67.1 (<0.001) 18.3 (<0.001) 1.0 (0.36)

LLB* – BASMI

LLB – DOMJAN

LLB – INSPIRE

82.0 (<0.001)

84.4 (<0.001)

75.8 (<0.001)

2.6 (0.82)

5.1 (0.01)

4.5 (0.46)

1.1 (0.27)

1.4 (0.04)

2.7 (0.04)

Intermalleolar

Internal Hip rotation

95.3 (<0.001)

91.3 (<0.001)

1.2 (0.04)

2.2 (0.15)

0.9 (<0.001)

0.8 (0.08)

Variation in Patients with PsA

*LLB=lateral lumbar bending; Xiph=xiphisternum; 4IC=4th intercostal space

The INSPIRE Study

Substantial to Excellent reliability was noted for: – Occiput-to-wall, cervical rotation, lateral bending, hip

mobility, modified Schober’s for both AS and PsA– Chest expansion at xiphisternum for PsA

The majority of the variation was due to patients

Assessor effect was noted for:– Occiput-to-wall, cervical rotation and chest expansion

for both AS and PsA, and modified Schober’s for PsA Order effect was noted only for intermalleolar

distance in PsA.

Summary

The INSPIRE Study

Measures of spinal mobility are reliable for AS.

Measures of spinal mobility that have been applied to primary AS perform well with respect to inter-observer reliability when applied to PsA patients with axial involvement.

These measures now need to be used in clinical trials and longitudinal cohort studies in PsA to confirm sensitivity to change.

Conclusions