Development of a candidate item bank for measuring mobility of lower limb orthosis users

Abstract

Background Orthoses are often prescribed to improve mobility of people with chronic health conditions that affect lower limb function. Patient‐reported survey instruments can be used to measure aspects of mobility that cannot be easily assessed in clinical or research settings. A population‐specific item bank could be designed to measure aspects of mobility that are most important to lower limb orthosis users and used to evaluate the effects of orthoses. Objective To develop items for a new survey instrument to measure mobility of lower limb orthosis users. Design Survey items were developed using a qualitative item review process. Setting Focus groups were held by video conferencing. Cognitive interviews were conducted by telephone. Participants Focus group and cognitive interview participants were adults with at least 6 months of experience using a lower limb orthosis that extended from the foot to a level above the ankle. Methods Research methods included focus groups with lower limb orthosis users, an item generation and reduction process that involved a stakeholder advisory panel, and cognitive interviews with target respondents. Results A total of 1180 extant items were identified in a literature review. Focus group participants (n = 29) provided feedback that informed the suitability of a construct definition and conceptual model. An advisory panel contributed to the selection of 118 candidate items for measuring orthotic mobility. Feedback from cognitive interview participants (n = 30) informed removal or revision of problematic items, resulting in a candidate bank of 100 mobility items. Conclusions The rigorous qualitative methods applied here resulted in a large set of candidate items that spanned a range of situations relevant to moving with a lower limb orthosis. Next steps include administration of the candidate items to a large sample of lower limb orthosis users and calibration of the item bank.

Development and initial validation of the Orthotic Patient-Reported Outcomes—Mobility (OPRO-M): An item bank for evaluating mobility of people who use lower-limb orthoses

“…A pool of candidate items was developed to measure aspects of mobility relevant to LLO users in prior work [ 19 ]. The process followed recommendations established by the PROMIS network for developing candidate items for an IRT-based PROM [ 20 ].…”

“…Focus groups were first conducted with LLO users to learn how mobility was affected by use of an orthosis, examine applicability of a previously-published conceptual model of mobility [ 14 ], assess a proposed construct definition, and solicit examples of activities people performed with their LLO. “Mobility” was defined as moving intentionally and without the help of another person [ 19 ]. Candidate items were generated from analysis of focus group transcripts, a literature review of PROMs designed to measure lower limb mobility, and input from clinical and scientific experts.…”

“…Lastly, cognitive interviews were conducted with LLO users to evaluate clarity and comprehensibility of each item, as well as the comprehensiveness of the content covered by all candidate items. These efforts resulted in a pool of 100 candidate items that addressed a wide range of activities and situations relevant to LLO use [ 19 ].…”

“…The purpose of this study was to develop the Orthotic Patient-Reported Outcomes–Mobility (OPRO-M), a self-report item bank for measuring mobility of LLO users. To achieve this goal, the previously-developed candidate item pool [ 19 ] was administered to a large national sample of LLO users. Results were used to identify items that fit an IRT model and could be included in the OPRO-M item bank.…”

A patient-centered ‘test-drive’ strategy for ankle-foot orthosis prescription: Protocol for a randomized participant-blinded trial

“…Participants will also be asked to rate their self confidence in their balance for walking on a treadmill, on stairs, and on a ramp (balance confidence questionnaire) during the in-lab sessions and after the community trials. At intake and after each community trial we will also collect the Quebec User Evaluation of Satisfaction with assistive Technology (QUEST 2.0), which will be used to evaluate a user’s satisfaction with assistive technologies [ 35 ], and the Orthotic Patient Reported Outcomes–Mobility (OPRO-M) [ 36 ] will be used to examine the ability of the participant to complete a range of challenging everyday mobility tasks with their assistive device(s). The Orthotics and Prosthetics Users’ Survey (OPUS) will be used to assess AFO function and satisfaction [ 37 ]; in this study, only the following two modules related to the lower extremity will be used: 1) Lower Extremity Functional Status Measure (LEFS) and 2) OPUS- Satisfaction with Devices and Services (questions 1–11 only).…”