A Comparison of Insoles Used to Prevent Neuropathic Diabetic Foot Ulceration

Diabetes Clinical Trial

Official title:

A Comparison of Functional and Prefabricated Insoles Used for the Preventative Management of Neuropathic Diabetic Foot Ulceration: a Single Blind Randomised Control Trial

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00999635
• Other study ID #: 05/Q2103/150
• Status: Completed
• Phase: Phase 2/Phase 3
• First received: October 21, 2009
• Last updated: October 23, 2009
• Start date: March 2006
• Est. completion date: September 2008

Study information

• Verified date: October 2009
• Source: University of Plymouth
• Contact: n/a
• Is FDA regulated: No
• Health authority: United Kingdom: Research Ethics Committee
• Study type: Interventional

Clinical Trial Summary

Importance of the topic:

Lower extremity amputation is a costly complication of diabetes for both the NHS and the patient. Amputation may be avoided if the preceding foot ulceration can be prevented. One method of reducing the risk of ulceration in the neuropathic foot is through the provision of therapeutic insoles. The type of insole prescribed (prefabricated verses custom made) is currently based on anecdotal evidence. The idea held by many practitioners that the custom made insole is superior in its effect remains speculation, unsupported by the evidence. In the absence of economic analysis, the available data suggests that the custom insole is substantially more expensive to the NHS. This study, to determine which of two types of insole used in therapeutic shoes reduces peak pressure more in the at−risk diabetic foot, is therefore a very important topic and will provide both useful evidence for the NHS podiatry services. It is of course also very important for patients with diabetes as the personal suffering of those undergoing amputation is immense.

The study is a single blind randomised controlled trial comparing custom made with 'off the shelf' insoles.

Description:

Aim The study compared custom-made functional insoles with prefabricated insoles for the preventative management of neuropathic diabetic feet, assessing effects on peak pressure, forefoot pressure time integral, total contact area, forefoot rate of loading, duration of load as a percentage of stance, quality of life, perceived foot health and cost.

Method Pilot work investigating the physical properties of materials used to fabricate insoles informed material selection. A single-blind randomised control trial recruited 119 neuropathic participants with diabetes from two Primary Care Trusts and randomly allocated them to either custom-made functional insoles or prefabricated insoles. Data was collected at issue and 6-month follow-up, using the F-scan in-shoe pressure measurement system. Patient perceptions were assessed with the Bristol Foot Score and Audit of Diabetes Dependant Quality of Life. Further analyses were carried out on two subgroups; 1) insole effect on peak pressure in 44 participants with pronated feet, over a 6-month follow-up period; 2) insole durability, investigated in a second subgroup of 60 participants for 12-months. Durability was evaluated in terms of change in insole thickness and reduction in peak pressure.

To increase the robustness of results, data analysis was calculated using three strategies; 1) pure intention-to-treat analysis, including all 119 participants randomised to an intervention; 2) intention-to-treat analysis, using all available data; 3) as-treated analysis, including those participants self-reporting full insole compliance, defined as 60% or more daytime wear.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 119
• Est. completion date: September 2008
• Est. primary completion date: September 2007
• Accepts healthy volunteers: No
• Gender: Both
• Age group: N/A and older

Eligibility

Inclusion Criteria:

• diagnosed as having Type 1 or 2 diabetes mellitus, (recorded within the case notes and confirmed by participant),

• diagnosed with diabetic peripheral neuropathy

• palpable or biphasic pulses

• intact from lower limb vascular or neuropathic ulceration, scoring Grade 0 on the Wagner classification for foot ulcer

• able to walk a minimum of 10 metres unaided

• willing to comply with the requirements of the study.

Exclusion Criteria:

• presented with current or recently healed ulceration less than 6 months prior to study enrolment,

• severe fixed mid-foot or rearfoot deformity e.g. charcot joint, unsuitable for prefabricated insoles and non- bespoke footwear,

• history of major bone or joint surgery of the lower limb including major amputation

• unable to comprehend simple instructions and comply with the study protocols and procedures.

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Single Blind (Subject), Primary Purpose: Prevention

Related Conditions & MeSH terms

• Diabetes
• Diabetic Foot
• Foot Ulcer
• Neuropathic Foot
• Ulcer

Intervention

Device:
• Insole
Comparison of custom made and prefabricated insoles designed for the neuropathic diabetic foot, issued for day time wear and followed for a 6 month period

Locations

Country	Name	City	State
United Kingdom	Liskeard Community Hospital	Liskeard	Cornwall
United Kingdom	Local Care Center Mount Gould	Plymouth	Devon

Sponsors (4)

Lead Sponsor	Collaborator
University of Plymouth	Cornwall and Illes of Scilly Primary Care Trust, Diabetes UK, Plymouth Teaching Primary Care Trust

Country where clinical trial is conducted

United Kingdom, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Reduction in peak pressure		6-months	No
Secondary	Comparison of cost		6-months	No