Session Information
Session Type: Abstract Submissions (ACR)
Background/Purpose
Cervical rotation reflects restriction of mobility in axial disease in ankylosing spondylitis (AS) and it can be assessed in several approaches based on the use of either an inclinometer, a goniometer or a tape measure. New generations of smartphones are equipped with a gyroscope and an accelerometer which in combination with a smartphone’s operating system or specific software applications can be used for various inclinometric functions. The aim of the study was to assess the reliability and validity of using iphone built in compass application, as compared to using goniometer in the assessment of cervical rotation patients with AS.
Methods
The study sample included 20 AS patients (6 females, 14 males) with a mean age of 47.8 (± 10.2) . BASMI scores were obtained from patient charts. Two examiners measured cervical rotation of each patient using iPhone4 compass application and also goniometer, twice with each method. A cap with a velcro patch on top and an iphone case with a Velcro patch on the bottom were used to stabilize the iphone’s position during measurements. Intra-rater and inter-rater reliability were examined with intra-class correlation coefficients (ICC). The agreement between the two methods was assessed by by Bland-Altman method
Results
The mean BASMI score of AS patients was 43 (± 22.7). The mean scores for BASDAI, ASDAS and BASFI were 3.7 (± 19.9) , 2.9 (± 0.96) and the 3.5 (± 2.4), respectively. We observed an excellent intra and inter-rater reliability in the whole study sample for both methods (Table 1 and Table 2). Bland-Altman analysis also showed a good agreement between the two methods (iphone-goniometer) with a mean difference (bias) of -1.7 for examiner 1 (95% CI −5.9 to −2.7) and -4.6 for examiner 2 (95% CI -8.9 to -0.4). Upper and lower limits of agreement were 16.6 (95% CI 9 to 24.2) and −19.9 (95% CI −27.4 to -12.3 ), for examiner 1 and 13.1(95% CI 5.7 to 20.4) and -22.3 (95% CI -29.6 to -15) for examiner 2.
Conclusion
Using iPhone compass application is a simple and accessible way of measuring cervical rotation in patients with AS. Measurements obtained with iphone show excellent intra and inter-rater reliability and a very good agreement with measurements obtained with goniometer.
Table.1 Mean cervical rotation measurements (degrees) with iPhone and goniometer and Intra-rater reliability for both methods
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Method |
Examiner 1 |
Examiner 2 |
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|
Trial 1 (Mean ± SD)* |
Trial 2 (Mean ± SD)* |
ICC |
95% CI for ICC |
Trial 1 (Mean ± SD)* |
Trial 2 (Mean ± SD)* |
ICC |
95% CI for ICC |
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|
Goniometer
|
46.8±16.5 |
46.3±16.5 |
0.98 |
0.97-0.99 |
46.5±16.9 |
46.4±16.6 |
0.98 |
0.97-0.99 |
|
iPhone |
48.3±22.1 |
48.1±21.3 |
0.98 |
0.96-0.99 |
51.8±21.3 |
50.3±20.1 |
0.96 |
0.90-0.98 |
*Mean of the right and left cervical rotation
Table 2 Mean cervical rotation measurements (degrees) with iPhone and goniometer and inter-rater reliability for both methods
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Examiner 1 (Mean ± SD)* |
Examiner 2 (Mean ± SD)* |
ICC |
95% CI |
|
Goniometer
|
46.6±16.44 |
46.5±16.91 |
0.99 |
0.97-0.99 |
|
iPhone4 |
48.2±21.6 |
51.05±20.49 |
0.93 |
0.84-0.97 |
*Mean of the two measurements by the same examiner
Disclosure:
G. Kenar,
None;
B. Zengin,
None;
H. Yarkan,
None;
P. Cetin,
None;
I. Sari,
None;
F. Onen,
None;
M. Birlik,
None;
N. Akkoc,
None.
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ACR Meeting Abstracts - https://acrabstracts.org/abstract/using-iphone-compass-application-for-the-assessment-of-cervical-rotation-in-patients-with-ankylosing-spondylitis/