The Oxford Ankle Foot Questionnaire for Children
The Oxford Ankle Foot Questionnaire for Children (OxAFQ-C) is a child – or parent (proxy)-reported self-report health status PRO. The OxAFQ-C is used to measure subjective well-being for child patients (aged 5-16) affected by foot and ankle conditions using issues that are considered important to children. Typical clinical assessments fail to capture the child patient’s perspective and may not accurately reflect how children function in their usual environments. The OxAFQ-C was therefore designed to supplement clinical assessments to evaluate the effectiveness of interventions for ankle/foot problems in children.
The OxAFQ-C is rapidly gaining acceptance as the PRO of choice for assessing the impact of ankle/foot conditions in children for the following reasons:
- It is the only PRO available assessing the impact of ankle foot issues on children from both the child and parent/caregivers perspective;
- The OxAFQ-C has broad utility both in routine clinical settings or applied research comparing different treatment programmes used in paediatric orthopaedics, trauma and rheumatology;
- A short (15-item) questionnaire that has proven to be easy to complete and returns high completion rates;
- Has been proven to be a valid and reliable (Morris et al 2008, see reference below) as well as being responsive and longitudinally valid (Morris et al 2009, see reference below).
The PRO
The OxAFQ-C has 15 items, 14 of which are used to calculate domain scores:
- Physical (6 items)
- School and Play (4 items)
- Emotional (4 items)
A final item (item 15 - Has your foot or ankle stopped you wearing any shoes you wanted to wear?) was added to reflect the concern by many children that they can or cannot wear the footwear they prefer.
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Scoring System
The scoring system is designed to assess how frequently each issue (represented by an item in the PRO) was a problem. Each item response has a 5-point scale rated from never (4), though rarely (3), sometimes (2), very often (1) to always (0), where the number in brackets represents the value applied to the response. As with classical approaches to measurement, domain scores, calculated as the total of the scale item score, are considered to be continuous and were transformed to a percentage scale. A higher score represents better functioning. Further details are provided in the development papers (Morris et al) cited below.
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Validated Therapeutic Areas
The OxAFQ-C is designed for children aged 5 – 16. The questionnaire can be used to assess treatments of ankle/foot conditions in the following categories:
- prevention or accommodation of deformities,
- management of related symptoms,
- improvement of physical function.
Using one or more the following therapies:
- physiotherapy,
- surgery,
- casting,
- orthoses,
- medication,
- advice.
Development
The OxAFQ-C was developed and tested in a 3 step process:
Phase 1 – Understanding the patient’s experience of their condition through qualified research.
Focus groups were convened with children affected by foot and ankle problems (along with their parent / caregiver) in three age groups, 5-7, 8-11 and 12-15. This research resulted in themes that children felt were important and affected them. Consistent themes identified by all groups were Physical Symptoms, activity limitations, reduced participation in certain contexts and self-consciousness due to appearance and other people’s attitudes. The results formed the basis of the PRO.
Phase 2 – Evaluation of test version in order to develop scales.
Initially 28 items were proposed (25 from Phase 1 and 3 extra from clinicians). Item responses were rated on a five-point scale indicating how frequently the issue affects the child, from never (score=4) to always (score=0). A survey of 158 children and their parents was carried out to determine the scaling, reliability and validity of the instrument. Exploratory factor analysis and Rasch analysis were used to devise the scales and refine the scaling.
Three domain scales were identified:
- Physical (6 items),
- Emotional (4 items), and
- School & Play (4 items)
As in classical approaches to measurement, domain scores are calculated as the total of the scale item scores and are transformed to a percentage scale (0-100), where a higher score represents better functioning. Although an item asking about ‘being able to wear the shoes you want’ did not fit with the scales, it was salient to many children and to most girls. The item has strong face validity and is included as a categorical descriptive variable but not allied to any domain scale. The remaining items were either redundant or did not improve the scaling and were dropped.
The three domain scales were shown to be internally consistent. The scales’ scores were also found to be stable at retest within two weeks, and to vary little whether reported by child or parent.
Phase 3 – Prospective study and further testing. In the third phase, a prospective study was conducted with 80 children attending trauma and elective orthopaedic clinics to assess responsiveness and longitudinal validity of the domain scales. Children and parents completed PROs at an initial outpatient appointment (baseline) and again within two weeks (retest), and finally a third set of PROs to complete again after two months (follow-up).
The follow up PROs included an additional global rating of change ‘transition’ item asking respondents to indicate whether they thought, overall, the foot or ankle problem was about the same, better or worse, on a seven point scale, using increments of ‘slightly’, ‘quite a bit’ and ‘a lot’ better or worse. The global rating of change provided a patient-based anchor for comparing the magnitude of changes in domain scores.
More details on the development process are available in the following articles:
Morris C., Liabo K., Wright P., and Fitzpatrick R. (2007) Development of the Oxford ankle foot questionnaire: finding out how children are affected by foot and ankle problems. Child: care and health development, 33, 5, 559-568.
Morris C., Doll, H., Wainwright A., Theologis T. and Fitzpatrick R. (2008) The Oxford ankle foot questionnaire for children. Scaling reliability and validity. J. Bone Joint Surg. (Br) 90-B:1451-6.
Morris C., Doll H., Davies N., Wainwright A., Theologis T., Willett K., Fitzpatrick R. (2009) The Oxford Ankle Foot Questionnaire for children: responsiveness and longitudinal validity. Qual. Life Res. 18:1367-1376
Morris C., Theologis T., Wainwright A., Davis N., Churchman D., Willett K. and Fitzpatruck R. (2010) Overview of the Development Phases of the Oxford Ankle Foot Questionnaire for Children. Poster presentation at ISPOR, Atlanta 2010.
An article on the development phases of the Oxford Ankle Foot Questionnaire for Children is available for download.
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Available Languages
Click here to access a list of available language versions.
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User Manual
A user manual is not currently available. Please enquire with Isis Outcomes about future availability of a manual for the OxAFQ-C.
Example Studies
These are some of the more specific ways the OxAFQ-C is currently employed by our user community:
- Clinical investigation into the impact of foot anomalies for patients with Aperts Syndrome,
- A pilot study foot pain and shape in teenagers,
- Multi Centre, randomised controlled trial, Heel raises versus prefabricated orthoses in the treatment of posterior heel pain associated with calcaneal apophysitis (Sever's disease),
- Ankle joint sprains in children and evaluating the outcome of therapy,
- Prospective Comparison of Hind Foot Stabilization Procedures in Children,
- Study to assess the efficacy of orthotic therapy in treatment of patients with a range of musculoskeletal/Orthopaedic foot and ankle conditions.
Other examples of conditions for which the OxAFQ-C has been used include:
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Diagnoses
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Pes plano-valgus
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Benign joint hypermobility
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Congenital Talipes Equino Varus
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Tarsal coalitions
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Pes cavus
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Metatarsus varus
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Hallux abducto-varus (bunion)
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Toe deformity
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Osteochondrosis/apophysitis
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Idiopathic toe walking
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Hereditary Motor Sensory Neuropathy
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Cerebral Palsy
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Down syndrome
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Marfan Syndrome
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Fractures
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Useful Links
The website for the University of Oxford’s Department of Primary Health Care, which includes the Division of Public Health & Primary Health Care, can be accessed at: www.publichealth.ox.ac.uk
Request a Licence
A license to use the OxAFQ-C can be obtained by completing the online licence request form.
If you would like further information about this PRO please contact one of the Isis Outcomes team.