Eddison, 2022 - Standardised Classification System For Bespoke
Eddison, 2022 - Standardised Classification System For Bespoke
Eddison, 2022 - Standardised Classification System For Bespoke
The Foot
journal homepage: www.elsevier.com/locate/foot
A R T I C L E I N F O A B S T R A C T
Keywords: Purpose: To validate a new classification system for bespoke thermoplastic ankle foot orthoses (AFOs).
Ankle foot orthoses Methods: Inter- and intra-observer reliability study. A classification system based on the design and function of
Orthotics AFOs was created. Sixty-three independent observers classified thirty-six photographs of different AFOs, ac
Terminology
cording to the proposed classification system via an online questionnaire. Approximately two weeks later, the
Classification systems
Evidence based medicine
same AFOs were classified again by fifty-three of the same participants. All participants were health care pro
fessionals, researchers, or technicians with experience in referring for, prescribing, fitting, reviewing, researching
or manufacturing AFOs.
Results: The mean inter- and intra-observer agreement Fleiss’ kappa was 0.932 and 0.944, respectively. 98.3% of
participants reported that the classification system was very easy or moderately easy to use, with 85.7%
reporting they would use the classification system. 90.5% of participants reported that the proposed AFO clas
sification system was clear, with 84% stating it was useful.
Conclusion: The proposed classification system for bespoke thermoplastic AFOs, has an excellent inter- and intra-
observer agreement. It will reduce the ambiguity of the description of the type of AFOs used in clinical practice
and research. Furthermore, it makes reproducible comparisons between groups possible, which are essential for
future evaluations of evidence-based orthotic care.
* Correspondence to: Centre for Biomechanics and Rehabilitation Technologies, Staffordshire University, Leek Road, Stoke on Trent ST4 2DF, United Kingdom.
E-mail address: Nicola.Eddison@staffs.ac.uk (N. Eddison).
1
Twitter: @OrthoticNetwork
2
Twitter: @AoifeCHealy
3
Twitter: @Daveblanche
4
Twitter: @NachiC
https://doi.org/10.1016/j.foot.2022.101924
Received 6 February 2022; Accepted 13 March 2022
Available online 17 March 2022
0958-2592/© 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
N. Eddison et al. The Foot 53 (2022) 101924
Fig. 2. An example of an articulated AFO. Fig. 3. An example of a rigid AFO with an incorporated anterior shell.
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N. Eddison et al. The Foot 53 (2022) 101924
2. Method
The approach utilised in this study follows the design used by Holla
et al. [27] for the classification of cervical spine immobilisation. To
determine the inter- and intra-observer agreement, photographs of
different AFOs were classified via an online questionnaire using Qual
trics (Qualtrics International, USA), by observers from a range of health
care professions involved in the provision of orthotic care. The group
comprised of practising clinicians, researchers and orthotic technicians
working in different healthcare settings and systems around the world
(see Table 1). The 1st questionnaire, to assess interobserver agreement,
Fig. 5. An example of a supra malleolar AFO. consisted of 51 questions in total with 36 classification questions . The
remaining 15 questions asked for: (see Table 2)
Clinicians and researchers alike are unequivocal that not all AFOs are
the same, they don’t treat the same pathologies and different designs • the participant’s profession,
have significantly different effects on biomechanical function. Yet the • if they were aware of any classification system which provides names
terms used to describe the different types of AFOs have not been clas for the different types of bespoke thermoplastic AFOs,
sified and defined, with descriptions and acronyms differing between • if they thought there was a need for a classification system,
researchers and clinicians; resulting in poorly designed research studies • if they thought the presented AFO classification system was clear,
[22,23], individual interpretation and a misunderstanding of research • the usefulness of the presented AFO classification system (ease of
outcomes. The lack of classification has resulted in generalisation on the use, effectiveness, and likelihood of using the proposed classification
effects of AFOs from research studies which have not been clear on the in the future).
design of the AFO used or the presenting pathology it was used for [23],
with some studies describing the AFO as “a standard AFO” [23] for To assess intraobserver agreement a 2nd questionnaire, consisting
which there is no definition. only of the 36 classification questions, was distributed to the same
Standardised terminology and definitions for AFOs are critical in participants approximately two weeks after completion of the 1st
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N. Eddison et al. The Foot 53 (2022) 101924
Table 1 Table 2
Professional background and country of the participants. Questions related to the use of the AFO classification system.
Number of observers Question Answer
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N. Eddison et al. The Foot 53 (2022) 101924
5
N. Eddison et al. The Foot 53 (2022) 101924
total of 35 photographs to be analysed. be a “rigid AFO” and this standardardisation of terminology allows the
Interobserver agreement n ¼ 63 participantsFleiss’ kappa was reader to understand which type of AFO is being tested and in turn al
run to determine if there was an agreement between participants’ lows necessary meta-analyses.
judgement on the 35 photographs of AFOs using the proposed classifi Currently there are six categories included in the proposed classifi
cation system. There was excellent agreement between the participants cation system, future work could see additional categories added.
classification of the AFOs κ = 0.932 (95% CI, .929–.936), p < .0005.
Individual kappa for the six types of AFOs were .913 for Rigid, .919 for
4.1. Strengths of this study
Flexible, .956 for Articulated,.946 for Rigid with separate anterior shell,
.886 for Rigid with incorporated anterior shell, and .978 for Supra-
The introduction of a validated simple and clear classification system
Malleollar.
for bespoke thermoplastic AFOs, considered useful by 84% of observers.
Intraobserver agreement: n ¼ 53 (10 participants out of the
The study has excellent inter- and intra-observer agreement results and
original 63 failed to respond to round two of the survey)Fleiss’
high validity due to 63 observers, from different occupations across 13
kappa was run to determine the intraobserver agreement, comparing the
countries around the world.
participants responses in round one to their responses in round two.
No classification system for bespoke thermoplastic AFOs currently
There was excellent agreement with a mean κ = 0.944 (range 0.404–1,
exists. This new validated classification is clinically relevant to improve
standard deviation: 0.11), p < .0005. Furthermore, 29 participants had
communication between healthcare professionals, allow meta-analyses
an individual Kappa score of κ = 1 and five participants had a Kappa
of AFO research and ultimately improve the treatment offered to AFO
score of < 0.8.
users. If adopted, it will be possible to group external treatment mo
Clinical usefulness
dalities using bespoke thermoplastic AFOs and to compare their effec
tiveness and clinical outcomes and perform meta-analyses. This
4. Discussion classification is essential for better evidence-based treatment of pa
thologies requiring a bespoke thermoplastic AFO intervention.
The results of this study show that 74.6% (n = 47) of participants
agreed that there is a need for a classification system for AFOs, of those
who responded “no” (n = 3) or “unsure” (n = 13) none gave an expla 4.2. Limitations
nation as to why they thought there was no requirement for an AFO
classification system. 76.1% (n = 48) of participants stated that they did This study relied on still photographic images of AFOs, four of the
not know of any AFO classification system, of the 23.8% (n = 15) who participants reported that the images were not always clear enough to
stated they did know of a classification system for AFOs, the systems determine the classification. Although this is a limitation of the current
they named did not classify AFOs (n = 5), was an unknown/unpublished study, it is not a limitation of the classification system as it is envisaged
classification system (n = 1) or the participant gave no response (n = 9). that the system would be used by researchers, clinicians and technicians
There are no validated classification systems for the different types of using the physical AFO they are manufacturing, studying, or issuing to a
bespoke thermoplastic AFOs in the current literature. user.
90.5% (n = 57) of participants reported that the proposed AFO
classification system was clear, with 84% (n = 53) stating it was useful, 5. Brief summary
of those who stated it was not useful (n = 2) or they were unsure if it was
useful (n = 8), none gave a response as to why they thought it wasn’t • Standardised terminology and definitions for AFOs are critical in
useful. 87.3% (n = 55) also reported having no issues using the classi clinical practice, without these, there may be serious negative con
fication system, of the eight participants who reported having issues sequences, with the potential to cause harm.
with the classification system, unclear photographs were the main cause • No classification system for bespoke thermoplastic AFOs currently
(n = 4), along with an apparent misunderstanding of the purpose of the exists. This new validated classification is clinically relevant to
classification system, with responses noting that it does not contain all improve communication between healthcare professionals.
possible permutations of AFO design. However, the purpose of the • The proposed classification system for bespoke thermoplastic AFOs,
classification system is to provide a category for the different types of based on AFO design and function has an excellent inter- and intra-
bespoke thermoplastic AFOs not the many intricate differences in observer agreement with Fleiss’ kappa values of 0.932 and 0.944,
design. respectively.
66.6% (n = 42) reported the classification system to be very easy to • 90.5% of the participants considered the classification to be clear.
use with a further 31.7% (n = 20) stating it was moderately easy. 85.7% • 85.7% of participants reported they would use the classification
(n = 54) reported they would use the classification system. system.
According to Landis and Koch, the inter- and intra-observer agree • With this validated classification system, it will be possible to
ment kappa values of this classification are rated “almost perfect” [28]. compare different treatment options using bespoke thermoplastic
The classification system should be used as a basis for all bespoke AFOs and perform meta-analyses, which is essential for future
thermoplastic AFO designs to negate the ambiguity of the current non- evidence-based practice and research.
standardised terms used to describe AFOs. This classification is the
basis to providing research which can be properly interpreted and for Conflict of interest statement
meta-analyses to be performed, this does not negate the need for re
searchers to provide full details of the individual design of the AFO All authors were fully involved in the study and preparation of the
including, foot plate length, medial-lateral borders of the foot plate, manuscript and declare that there is no conflict of interest.
strapping system, material type, joint type and thickness [23,29,30].
The classification system is not intended to be used as a prescription
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