Use of Standardized Outcome Measures for People With Lower Limb Amputation: A Survey of Prosthetic Practitioners in the United States

Performance-based and patient-reported outcome measures for custom ankle-foot orthosis users: reliability, validity, and sensitivity evidence

PURPOSE

To evaluate the psychometric properties of performance and patient-reported outcome measures (PROMs) for custom ankle-foot orthosis (AFOs) users.

MATERIALS AND METHODS

Current AFO users completed two assessments one week apart; new AFO users completed an assessment before device delivery and at one- and two-months post-delivery.

RESULTS

Seventy current and 31 new users consented and provided data. We found evidence of minimal floor and ceiling effects for most PROMs; the exceptions were measures of service satisfaction. The Orthotics and Prosthetics Users' Survey (OPUS) Lower Extremity Functional Status (LEFS) measure demonstrated excellent test-retest reliability; the 5-level EuroQol (EQ-5D-5L), OPUS Health-Related Quality of Life, Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST 2.0), and PROMIS Physical Function measures demonstrated good reliability. Evidence of known-groups validity is provided by associations between obesity and walking speed. PROMs measuring physical function (LEFS, Rivermead Mobility Index (RMI), PROMIS Physical Function) correlated at least moderately with performance instruments. We observed moderate to large correlations between PROM and performance instrument changes for the EQ-5D-5L, LEFS, RMI, and PROMIS Physical Function.

CONCLUSIONS

Results provide evidence of test-retest reliability, construct validity, and sensitivity to change for some PROMs. PROMs and performance instruments provide overlapping but complementary evidence regarding the benefits of custom AFOs.

Use of standardized outcome measures for people with lower-limb amputation: A survey of prosthetic practitioners in Canada

BACKGROUND

Outcome measures (OMs) are useful tools; however, clinicians may find implementing them into clinical practice challenging.

OBJECTIVES

To characterize Canadian prosthetists' use of OMs for people with lower-limb amputation, including motivations for use, comfort selecting OMs, resources available for administration, and barriers to implementation.

METHODS

A cross-sectional study was conducted between March and July 2021. Orthotics Prosthetics Canada sent Canadian prosthetists an invitation to take the online survey.

RESULTS

Forty-nine Certified Prosthetists completed the survey. Only 16% of participants reported that they were expected to use OMs. Participants reported being more comfortable administering performance-based OMs than self-report surveys. More than two-thirds of participants agreed that OMs "can be administered with knowledge they have" and are "within their scope of practice." However, less than 25% agreed that OMs are "administered in a standardized way in the profession," and less than 40% indicated they are "easy to make part of my routine." Participants reported they generally have time and space to do OMs, but there was no agreed-on reason to use them.

CONCLUSIONS

Use of OMs among Canadian prosthetists seems to be low relative to prosthetists in the United States. Education, financial incentives, or changes to professional expectations are likely needed to increase routine OM use. Efforts to improve the standardization of OM administration and ease the incorporation of OMs into routine practice may also increase use. Canadian prosthetists may elevate their standards of clinical practice and better understand the impact of prosthetic treatments on their patients by more routinely using OMs.

Development and pilot administration of the amputation-related pain and sensation assessment tool

PURPOSE

To develop and administer an assessment tool for facilitating patient-clinician discussions regarding amputation-related pain and sensation.

MATERIALS AND METHODS

An assessment tool was developed to measure the impact of different types of amputation-related pain and sensation on a patient's life. The tool first provides patients with written descriptions and images of three common types of amputation-related pain or sensations: residual limb pain, phantom limb sensation, and phantom limb pain. The tool then asks them to rate the frequency, intensity, and interference of each experience. Participants were also asked to provide qualitative descriptions of these experiences.

RESULTS

Fifty Veterans with lower limb amputation participated in the study. In the past month, 74% reported experiencing residual limb pain, 76% reported phantom limb sensation, and 84% reported phantom limb pain, with 52% reporting all three. Participants' descriptions of some experiences were distinct, while others (e.g., "tingling") were common between experiences. Phantom limb pain had the most varied descriptions.

CONCLUSIONS

The amputation-related pain and sensation assessment tool can be used to identify and measure the effects of different experiences on patients' lives, thereby improving the specificity of diagnosis and informing clinical treatment recommendations. Further development of this tool should include evaluating its psychometric properties.

Reporting of Rehabilitation Outcomes in the Traumatic Lower Limb Amputation Literature: A Systematic Review

OBJECTIVE

To synthesize the outcomes reported in the rehabilitation and community literature for adults with traumatic lower limb amputation (LLA).

DATA SOURCES

The search strategy was conducted in 3 databases (Medline, EMBASE, and CINAHL) from inception to April 2022.

STUDY SELECTION

To be eligible, articles could be of any design but were required to have at least 50% adult individuals with traumatic LLA and had to report on interventions and outcomes in either a rehabilitation or community setting.

DATA EXTRACTION

The extracted outcomes were classified using Dodd's framework, which is designed for organizing research outcomes. Heterogeneity was observed in the outcome measures (OMs) used for evaluation. Two reviewers independently conducted the data extraction, which was verified by a third reviewer.

DATA SYNTHESIS

Of the 7,834 articles screened, 47 articles reporting data on 692 individuals with traumatic LLA, met our inclusion criteria. Four core areas encompassing 355 OMs/indicators were identified: life effect (63.4%), physiological/clinical (30.1%), resource use (5.1%), and adverse events (1.4%). Physical functioning (eg, gait, mobility) was the most frequently reported outcome domain across studies, followed by nervous system outcomes (eg, pain) and psychiatric outcomes (eg, depression, anxiety). Domains such as global quality of life and role/emotional functioning were seldomly reported.

CONCLUSION

The study provides a list of outcome indicators explicitly published for adults with traumatic LLA, highlighting inconsistent reporting of outcome indicators. The lack of a standardized set of OMs is a barrier to performing meta-analyses on interventions, preventing the identification of effective care models and clinical pathways. Developing a core outcome set that includes OMs relevant to the needs of the traumatic LLA population may address these issues.

Validating a fear-of-falling-related activity avoidance scale in lower limb prosthesis users

BACKGROUND

Limited available data suggest that fear of falling (FoF) may be common among lower limb prosthesis users (LLPUs) and associated with negative rehabilitation outcomes. The impact of FoF on outcomes may be exacerbated when fear leads to self-imposed declines in activity. There is a need to identify the validity of fear-of-falling-related activity avoidance scales in LLPUs.

OBJECTIVE

To evaluate the convergent, discriminant, and known-group construct validity of the modified Survey of Activities and FoF in the Elderly (mSAFE) for LLPUs. Secondarily, we sought to determine if the mSAFE scale could be reduced without losing information regarding construct validity.

DESIGN

Online survey.

SETTING

Not applicable.

PARTICIPANTS

Fifty-nine persons with unilateral or bilateral amputation at the transtibial or transfemoral level, with ≥6 months experience using a definitive prosthesis for activities other than transfers.

INTERVENTION

Participants completed an online survey that consisted of the mSAFE and questions to assess FoF (yes/no), fear-of-falling-related activity avoidance (yes/no), as well as previously validated scales capturing related and unrelated constructs. T-tests were used to compare mSAFE score between yes/no respondents for known-group construct validity. Correlations between mSAFE and previously validated surveys assessed convergent and discriminant validity. Analyses were repeated on a reduced number of mSAFE items following a redundancy analysis.

MAIN OUTCOME MEASURES

Not applicable.

RESULTS

Significant correlation coefficients of |0.440-0.825| were found for convergent validity with evidence of known-group construct validity (p < .021 for all comparisons). There was evidence for discriminant validity, with non-significant associations for two-of-three correlations. Results from validity analyses for a shortened 6-item mSAFE were similar to that for the full scale.

CONCLUSION

This study provided initial evidence regarding validity of the mSAFE as a measure to assess fear-of-falling-related activity avoidance in LLPUs. A 6-item scale may be appropriate if the full scale would be taxing or time-consuming.

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

Lower limb orthoses (LLOs) are externally-applied leg braces that are designed to improve or maintain mobility in people with a variety of health conditions that affect lower limb function. Clinicians and researchers are therefore often motivated to measure LLO users' mobility to select or assess the effectiveness of these devices. Patient-reported outcome measures (PROMs) can provide insights into important aspects of a LLO user's mobility for these purposes. However, few PROMs are available to measure mobility of LLO users. Those few that exist have issues that may limit their clinical or scientific utility. The objective of this study was to create a population-specific item bank for measuring mobility of LLO users. Previously-developed candidate items were administered in a cross-sectional study to a large national sample of LLO users. Responses from study participants (n = 1036) were calibrated to a graded response statistical model using Item Response Theory methods. A set of 39 items was found to be unidimensional, locally independent, and function without bias due to characteristics unrelated to mobility. The set of final calibrated items, termed the Orthotic Patient-Reported Outcomes-Mobility (OPRO-M) item bank, was evaluated for initial evidence of convergent, divergent, and known groups construct validity. OPRO-M was strongly correlated with existing PROMs designed to measure aspects of physical function. Conversely, OPRO-M was weakly correlated with PROMs that measured unrelated constructs, like sleep disturbance and depression. OPRO-M also showed an ability to differentiate groups with expected mobility differences. Two fixed-length short forms were created from the OPRO-M item bank. Items on the short forms were selected based on statistical and clinical criteria. Collectively, results from this study indicate that OPRO-M can effectively measure mobility of LLO users, and OPRO-M short forms can now be recommended for use in routine clinical practice and research studies.

Development of an item bank for measuring prosthetic mobility in people with lower limb amputation: The Prosthetic Limb Users Survey of Mobility (PLUS-M)

BACKGROUND

Achieving mobility with a prosthesis is a common post-amputation rehabilitation goal and primary outcome in prosthetic research studies. Patient-reported outcome measures (PROMs) available to measure prosthetic mobility have practical and psychometric limitations that inhibit their use in clinical care and research.

OBJECTIVE

To develop a brief, clinically meaningful, and psychometrically robust PROM to measure prosthetic mobility.

DESIGN

A cross-sectional study was conducted to administer previously developed candidate items to a national sample of lower limb prosthesis users. Items were calibrated to an item response theory model and two fixed-length short forms were created. Instruments were assessed for readability, effective range of measurement, agreement with the full item bank, ceiling and floor effects, convergent validity, and known groups validity.

SETTING

Participants were recruited using flyers posted in hospitals and prosthetics clinics across the United States, magazine advertisements, notices posted to consumer websites, and direct mailings.

PARTICIPANTS

Adult prosthesis users (N = 1091) with unilateral lower limb amputation due to traumatic or dysvascular causes.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Candidate items (N = 105) were administered along with the Patient Reported Outcome Measurement Information System Brief Profile, Prosthesis Evaluation Questionnaire - Mobility Subscale, and Activities-Specific Balance Confidence Scale, and questions created to characterize respondents.

RESULTS

A bank of 44 calibrated self-report items, termed the Prosthetic Limb Users Survey of Mobility (PLUS-M), was produced. Clinical and statistical criteria were used to select items for 7- and 12-item short forms. PLUS-M instruments had an 8th grade reading level, measured with precision across a wide range of respondents, exhibited little-to-no ceiling or floor effects, correlated expectedly with scores from existing PROMs, and differentiated between groups of respondents expected to have different levels of mobility.

CONCLUSION

The PLUS-M appears to be well suited to measuring prosthetic mobility in people with lower limb amputation. PLUS-M instruments are recommended for use in clinical and research settings.

Modifying the five-time sit-to-stand test to allow use of the upper limbs: Assessing initial evidence of construct validity among lower limb prosthesis users

The Five-time Sit-to-Stand (5xSTS) Test is a performance-based measure used by clinicians and researchers to assess the body functions needed to accomplish sit-to-stand transitions (e.g., lower limb strength, balance, and trunk control). The current requirements for performance of the 5xSTS Test (i.e., crossing arms over the chest) may not be appropriate for many, if not most lower limb prosthesis (LLP) users. The study aims were to (1) develop a modified five-time sit-to-stand (m5xSTS) Test protocol; (2) to examine initial evidence of known-groups construct validity among LLP users by comparing differences in performance by amputation level, amputation etiology, and functional level; and (3) to assess initial evidence of convergent construct validity by examining the correlations between m5xSTS performance with self-reported mobility (Prosthetic Limb Users Survey of Mobility (PLUS-M)), self-reported balance confidence (Activities-balance Confidence Scale (ABC)) and functional capability (comfortable walking speed). Three-hundred sixty-one LLP users participated in this cross-sectional study. The investigators developed a m5xSTS Test protocol that allows tested individuals to use different assistance strategies (i.e., use of upper limbs to push off thighs, push up from the armrests, or use a walker) when needed to perform the test. The investigators recorded m5xSTS Test times and assistance strategies. Significant differences in m5xSTS Test times were found between those who did and did not use an assistance strategy, as well as between participants grouped by different amputation level, etiology, and functional level. Significant moderate negative correlations were found between m5xSTS Test times and PLUS-M T-score (ρ = -0.42, p<0.001), ABC score (ρ = -0.42, p<0.001), and comfortable walking speed (ρ = -0.64, p<0.001), respectively. The m5xSTS Test allows LLP users to perform sit-to-stand transitions in a manner that accounts for their functional impairments, is consistent with post-amputation training, and is safe for the tested individual. Results from this study provide preliminary evidence of known groups and convergent construct validity for the m5xSTS Test with a large national sample of LLP users.