Helen Y N Lindner

Upper limb prosthetic outcome measures: Review and content comparison based on International Classification of Functioning, Disability and Health

The International Classification of Functioning, Disability and Health (ICF) has been recommended as a framework for evaluation of aspects of health. The aim of this study was to compare the contents of outcome measures for upper limb prosthesis users by using the ICF. Measurement focus and psychometric properties of these measures were also investigated. Outcome measures that used upper limb prosthesis users as subjects in their development and psychometric evaluations were selected. The psychometric studies (n = 14) were reviewed and scored and the items in the measures were linked to the ICF. One measure for all ages (ACMC), five paediatric measures (CAPP-FSI, CAPP-PSI, PUFI, UBET and UNB) and two adult measures (OPUS and TAPES) were selected. The concepts extracted (n = 393) were linked to 54 categories in the ICF. The ACMC, CAPP-FSI, UBET, UNB and PUFI measure categories mostly under the ICF component ‘Activity and participation’. The TAPES and OPUS also measure ICF categories that describe the emotional and social status of a person. The main conclusion is that the use of a mixture of outcome measures would give a better picture on the aspects of our clients. Measures that focus on the social interaction in paediatric users are required.

Influence of standardized activities on validity of Assessment of Capacity for Myoelectric Control

The Assessment of Capacity for Myoelectric Control (ACMC) is an observation-based clinical tool that evaluates ability to control a myoelectric prosthetic hand during bimanual activities. Two validity aspects were investigated: potential bias interaction between prosthesis users and activities performed during assessment, and potential bias interaction between activities and different user characteristics (sex or prosthetic side). Six activities were standardized for the ACMC. Upper-limb myoelectric prosthesis users (47 congenital, 11 acquired; 31 male, 27 female, average age 19.9 yr) performed three standardized activities, each on one occasion. Bias-interaction analysis in the many-facet Rasch model identified inconsistent patterns in the interactions of individual users and activity facets and between activities and user characteristics. The standardized activities had no significant influence on measures of user ability. The activities functioned similarly across both sexes (p-value greater than or equal to0.12) and across both prosthetic sides in persons with upper-limb reduction deficiency (p-value greater than or equal to0.50) and persons with acquired amputation (p-value greater than or equal to0.13). The results provide evidence for the validity of the ACMC across the standardized activities and support use of the ACMC in prosthesis users of both sexes and prosthetic sides. The newly standardized activities are recommended for future ACMC use.

Test-retest reliability and rater agreements of assessment of capacity for myoelectric control version 2.0

The Assessment of Capacity for Myoelectric Control (ACMC) is an observation-based tool that evaluates ability to control a myoelectric prosthetic hand. Validity evidence led to ACMC version 2.0, but the test-retest reliability and minimal detectable change (MDC) of the ACMC have never been evaluated. Investigation of rater agreements in this version was also needed because it has new definitions in certain rating categories and items. Upper-limb prosthesis users (n = 25, 15 congenital, 10 acquired; mean age 27.5 yr) performed one standardized activity twice, 2 to 5 wk apart. Activity performances were videorecorded and assessed by two ACMC raters. Data were analyzed by weighted kappa, intraclass correlation coefficient (ICC), and Bland-Altman method. For test-retest reliability, weighted kappa agreements were fair to excellent (0.52 to 1.00), ICC2,1 was 0.94, and one user was located outside the limits of agreement in the Bland-Altman plot. MDC95 was less than or equal to 0.55 logits (1 rater) and 0.69 logits (2 raters). For interrater reliability, weighted kappa agreements were fair to excellent in both sessions (0.44 to 1.00), and ICC2,1 was 0.95 (test) and 0.92 (retest). Intrarater agreement (rater 1) was also excellent (ICC3,1 0.98). Evidence regarding the reliability of the ACMC is satisfactory and MDC95 can be used to indicate change.

Is the Autism-Spectrum Quotient a Valid Measure of Traits Associated with the Autism Spectrum? A Rasch Validation in Adults with and Without Autism Spectrum Disorders

The Autism-Spectrum Quotient (AQ) is among the most widely used scales assessing autistic traits in the general population. However, some aspects of the AQ are questionable. To test its scale properties, the AQ was translated into Swedish, and data were collected from 349 adults, 130 with autism spectrum disorder (ASD) and 219 without ASD, and analysed with Rasch. Several scale properties of the AQ were satisfactory but it did not meet the criterion of a unidimensional measure of autistic traits. The Rasch analysis showed that the 50-item AQ could be reduced to a 12-item subset with little loss of explanatory power, with the potential to efficiently measure the degree to which adults with and without ASD show autistic traits.

Relation between capacity and performance in paediatric upper limb prosthesis users

Background: The International Classification of functioning, disability and health refers capacity to what an individual can do in a standardised environment and describes performance as what an individual really does and whether the individual encounters any difficulty in the real-life environment. Measures of capacity and performance can help to determine if there is any gap between them that may restrict participation. The aim of this study was to explore the relationship between capacity scores obtained in a standardised clinical setting and proportional ease of performance obtained from a real-life environment. Methods: The Assessment of Capacity for Myoelectric Control and the Prosthetic Upper Extremity Functional Index were used to assess capacity and performance in 62 prosthetic users (age 3–17). Spearman coefficient and generalised linear model were used to examine the association between these measures. Results: A strong correlation (Spearman = 0.75) was found between the capacity scores and the ease of performance. In both unadjusted and adjusted models, capacity was significantly associated with proportional ease of performance. The adjusted model showed that, by 1 unit increase in the Assessment of Capacity for Myoelectric Control score, the ratio of proportional ease of performance increases by 45%. Conclusion: This implies that Assessment of Capacity for Myoelectric Control can be a predictor for ease of performance in real-life environment. Clinical relevance The ACMC scores may serve as an indicator to predict the difficulties that the children may encounter in their home environment. This prediction can help the clinician to make decisions, such that if the child requires more control training or is ready to move on to learn more complex tasks.

Long-term results of early myoelectric prosthesis fittings: A prospective case-control study:

Background: Different recommendations exist regarding what age is best for first-time fitting of myoelectric hand prostheses in children. Objectives: To compare prosthetic skill, prosthetic use and risk for rejection over time between children fitted with myoelectric hand prostheses before or after 2½ years of age. Study design: Prospective case-control design. Methods: The cases were nine children fitted with myoelectric hand prostheses before the age of 2½ years, whereas the controls were 27 children who were fitted with myoelectric hand prostheses after the age of 2½ years. The Skills Index Ranking Scale was used to classify prosthetic skill, and prosthetic use was categorised based on wearing time and pattern. Independent samples tests were used to compare data between groups. To estimate and compare the risk of prosthesis rejection between groups and over time, survival analysis was used. Results: Cases showed prosthetic skill early, but controls had caught up by the age of 3½ years. Cases had a significant (p = 0.046) decrease in prosthetic use at the age of 9 years. In the long term, cases had a higher percentage of prosthesis rejection. Conclusions: Considering young children’s development of prosthetic skill and prosthetic use over time, this study shows no additional advantages from fitting a myoelectric hand prosthesis before 2½ years of age. Clinical relevance Children may be fitted with myoelectric hand prostheses to assist in daily tasks and to prevent future over-use problems. Most children fitted with myoelectric hand prostheses before 4 years of age become regular users. No advantages of fitting myoelectric hand prostheses before 2½ years of age were observed.