Helena Burger

Assessing and adjusting for cross-cultural validity of impairment and activity limitation scales through differential item functioning within the framework of the Rasch model the pro-esor project

IntroductionIn Europe it is common for outcome measures to be translated for use in other languages. This adaptation may be complicated by culturally specific approaches to certain tasks; for example, bathing. In this context the issue of cross-cultural validity becomes paramount. ObjectiveTo facilitate the pooling of data in international studies, a project set out to evaluate the cross-cultural validity of impairment and activity limitation measures used in rehabilitation from the perspective of the Rasch measurement model. MethodsCross-cultural validity is assessed through an analysis of Differential Item Functioning (DIF) within the context of additive conjoint measurement expressed through the Rasch model. Data from patients undergoing rehabilitation for stroke was provided from 62 centers across Europe. Two commonly used outcome measures, the Mini-Mental State Examination (MMSE) and the Functional Independence Measure (FIM) motor scale are used to illustrate the approach. ResultsPooled data from 3 countries for the MMSE were shown to fit the Rasch model with only 1 item displaying DIF by country. In contrast, many items from the FIM expressed DIF and misfit to the model. Consequently they were allowed to be unique across countries, so resolving the lack of fit to the model. ConclusionsWhere data are to be pooled for international studies, analysis of DIF by culture is essential. Where DIF is observed, adjustments can be made to allow for cultural differences in outcome measurement.

Validation of the "World Health Organization Disability Assessment Schedule, WHODAS-2" in patients with chronic diseases

BackgroundThe WHODAS-2 is a disability assessment instrument based on the conceptual framework of the International Classification of Functioning, Disability, and Health (ICF). It provides a global measure of disability and 7 domain-specific scores. The aim of this study was to assess WHODAS-2 conceptual model and metric properties in a set of chronic and prevalent clinical conditions accounting for a wide scope of disability in Europe.Methods1,119 patients with one of 13 chronic conditions were recruited in 7 European centres. Participants were clinically evaluated and administered the WHODAS-2 and the SF-36 at baseline, 6 weeks and 3 months of follow-up. The latent structure was explored and confirmed by factor analysis (FA). Reliability was assessed in terms of internal consistency (Cronbachs alpha) and reproducibility (intra-class correlation coefficients, ICC). Construct validity was evaluated by correlating the WHODAS-2 and SF-36 domains, and comparing known groups based on the clinical-severity and work status. Effect size (ES) coefficient was used to assess responsiveness. To assess reproducibility and responsiveness, subsamples of stable (at 6 weeks) and improved (after 3 moths) patients were defined, respectively, according to changes in their clinical-severity.ResultsThe satisfactory FA goodness of fit indexes confirmed a second order factor structure with 7 dimensions, and a global score for the WHODAS-2. Cronbachs alpha ranged from 0.77 (self care) to 0.98 (life activities: work or school), and the ICC was lower, but achieved the recommended standard of 0.7 for four domains. Correlations between global WHODAS-2 score and the different domains of the SF-36 ranged from -0.29 to -0.65. Most of the WHODAS-2 scores showed statistically significant differences among clinical-severity groups for all pathologies, and between working patients and those not working due to ill health (p < 0.001). Among the subsample of patients who had improved, responsiveness coefficients were small to moderate (ES = 0.3-0.7), but higher than those of the SF-36.ConclusionsThe latent structure originally designed by WHODAS-2 developers has been confirmed for the first time, and it has shown good metric properties in clinic and rehabilitation samples. Therefore, considerable support is provided to the WHODAS-2 utilization as an international instrument to measure disability based on the ICF model.

Return to work after lower limb amputation.

Purpose. To review the literature on return to work after lower limb amputation. Method. A comprehensive review of literature on return to work after lower limb amputation was carried out, searching MEDLINE and PubMED. Results. Most authors found return-to-work rate to be about 66%. Between 22 and 67% of the subjects retained the same occupation, while the remainder had to change occupation. Post-amputation jobs were generally more complex with a requirement for a higher level of general educational development and were physically less demanding. The return to work depends on: general factors, such as age, gender and educational level; factors related to impairments and disabilities due to amputation (amputation level, multiple amputations, comorbidity, reason for amputation, persistent stump problems, the time from the injury to obtaining a permanent prosthesis, wearing comfort of the prosthesis, walking distance and restrictions in mobility); and factors related to work and policies (salary, higher job involvement, good support from the implementing body and the employer and social support network). Conclusions. Subjects have problems returning to work after lower limb amputation. Many have to change their work and/or work only part-time. Vocational rehabilitation and counselling should become a part of rehabilitation programme for all subjects who are of working age after lower limb amputation. Better cooperation between professionals, such as rehabilitation team members, implementing bodies, company doctors and the employers, is necessary.

VALIDATION OF THE ORTHOTICS AND PROSTHETICS USER SURVEY UPPER EXTREMITY FUNCTIONAL STATUS MODULE IN PEOPLE WITH UNILATERAL UPPER LIMB AMPUTATION

OBJECTIVE To evaluate the measurement properties of the Upper Extremity Functional Status module of the Orthotics and Prosthetics User Survey (OPUS). DESIGN Methodological research on an outcome measure administered by clinical interview. PATIENTS A convenience sample of 61 adults who had unilateral upper limb amputations and completed rehabilitation at the Institute for Rehabilitation in Ljubljana, Slovenia, at least one year prior to interview. Thirty-four patients had undergone amputation of the dominant hand. Four patients did not use a prosthesis. METHODS Rating scale analysis (Rasch model) was used to evaluate functioning of the rating scale categories, the validity of the measure by examining fit of items to the latent trait, and the hierarchy of item difficulties compared with expectations of the construct. RESULTS Rasch analysis allowed us to improve the Upper Extremity Functional Status by rescoring to reduce the response categories from 5 to 4, and identifying 19 of 23 items that are useful to measure upper extremity function. The results allow us to have high confidence in the consistency of both person-ability and item-difficulty estimates. CONCLUSION This revised Upper Extremity Functional Status is a promising instrument to measure the degree of manual functioning after a unilateral upper limb amputation.

Influence of speed on gait parameters and on symmetry in transtibial amputees

Normal gait is characterised by a high level of inter-leg symmetry of gait parameters. Therefore, efforts in rehabilitation of amputees are directed at the construction of a prosthesis which provides normal leg function and allows a more symmetrical gait. Analysis of the gait of trans-tibial amputees was performed when they were ambulating at their own freely selected speed and at a faster speed. The effect of speed on selected gait parameters in each leg was evaluated and the influence on symmetry established by comparing the inter-leg changes for each of the selected parameters. The faster gait trail affected significantly all temporal and distance parameters in both legs but not the level of symmetry between legs. At the faster speed, the hip angles at heel-strike and during swing and the knee angle during load response, in the normal leg, and the knee angle during swing in the amputated leg, all increased significantly. Speed of gait significantly affected symmetry between knee angles as reflected by the increased differences measured during load response (from 2.62 ±5.2 to 7.06 ±4.2 degrees) and during toe-off (from 1.80 ±7.4 to 9.50 ±9.1 degrees). Timing and sequence of selected gait events, as related to stride time, were not significantly affected by speed of gait. These results might contribute to a better understanding of gait characteristics in trans-tibial amputees and provide design guidance for prosthetic components.

The influence of post-polio syndrome on independence and life satisfaction

Purpose : The aim of the study was to find out the influence of the new symptoms on life satisfaction and independent living and the most frequent disabilities in patients with post-polio syndrome that are affecting the satisfaction and independence. Method : A questionnaire was sent to all the post-polio survivors (207) who visited the Rehabilitation Institute in Ljubljana at least once in the last ten years. We got 100 answers, which were analysed by SPSS (statistical package for social sciences). Results : Sixty nine reported that they had new symptoms that may be classified as post-polio syndrome. Conclusions : We have found that the new symptoms in postpolio survivors, which may be classified as post-polio syndrome, increased their walking and climbing stairs disability, increased their disability to perform daily activities and also decreased their satisfaction with life.

Mobility of persons after traumatic lower limb amputation

The objective of this study was to determine the influence of time span since amputation on mobility of persons experiencing traumatic lower limb amputation. A special questionnaire was sent to such persons and responses were analysed statistically. The subjects comprised 223 persons after traumatic lower limb amputation, residents of Slovenia. We discovered that 186 (74.2%) are using their prosthesis for more than 7 hours per day, 109 (52.2%) are able to walk outdoors without crutches, and 129 (57.8%) climb more than 20 stairs per day. In addition, those who are walking without crutches, walking longer distances, still cycling and driving a care are, on average, 5-10 years younger than the others. However, around one-third of persons who were young at the time of amputation face limitations of mobility later in life. A total of 76 (35.3%) are able to walk only up to 500 m out of doors, 38 (18.2%) can walk only with a pair of crutches, 62 (29.7%) need a cane or one crutch, and 37 (16.6%) cannot climb stairs. We conclude that successful fitting and usage of a prosthesis by persons after lower limb amputation promotes independent walking and mobility in everyday life. The level of independence achieved is related to time span since amputation.

Telerehabilitation using virtual reality task can improve balance in patients with stroke

Purpose: The objective of the telerehabilitation is a continuation of the rehabilitation process on patients’ home. The study also compares the balance training in clinical environment with the telerehabilitation approach when the physiotherapists and physicians can follow the progress remotely. Method: In this paper, the preliminary study of the pilot project with virtual reality (VR)-based tasks for dynamic standing frame supported balance training is presented. Six patients with stroke participated in the study. The patients performed the balance training 3 weeks, 2 weeks in the clinical settings and 1 week in the home environment, five times a week, and each time for up to 20 minutes. Objective effectiveness was demonstrated by parameters as track time, number of collisions and the clinical instruments Berg Balance Scale (BBS), Timed Up & Go (TUG), 10-m walk test and standing on the unaffected and affected extremity. The outcomes were compared to the balance training group without VR and telerehabilitation support. A 2-way ANOVA was used to explore the differences between the both stroke groups. Results: In patients who were subject to VR supported balance training, the BBS demonstrated improvement for 15%, the TUG for 29%, the 10-m walk for 26%, stance time on the affected and unaffected extremity for 200 and 67%, respectively. The follow-up demonstrated that the patients preserved the gained functional improvement. The VR task performance time and number of collisions decreased to 45 and 68%, respectively. Besides, no statistical differences were found between the telerehabilitation approach with VR supported balance training and conventional balance training in clinical settings either regarding the overall mean level or regarding the mean improvement. Conclusions: The telerehabilitation approach in VR supported balance training improved balance in stroke patients and had similar effect on patients’ postural functional improvement as conventional balance training in clinical settings. However, when balance training is continued on patient’s home instead of the hospital, it would eventually decrease the number of outpatients’ visits, reduce related costs and enable treatment of larger number of patients. Implications for Rehabilitation People suffering from stroke have severe problems with posture and balance. This study demonstrates that using target based tasks in a virtual environment can improve balance in stroke population. Telerehabilitation offers continuation of balance training in the remote centres or at home. The longer rehabilitation period improves functionality and therefore the quality of life.

Influence of foot orthoses on plantar pressures, foot pain and walking ability of rheumatoid arthritis patients–a randomised controlled study

Purpose. To compare the effectiveness of functional foot orthoses and unshaped (flat) orthotic material on plantar pressure redistribution, forefoot pain reduction and walking ability in rheumatoid arthritis (RA) patients. Methods. Forty patients with RA were randomised to receive unshaped material (UM) (n = 20) or functional foot orthoses (n = 20). Plantar pressure measurement was performed with an F-scan system. Foot pain was assessed by the pain subscale of the Foot Function Index. Walking ability was assessed by the 6-min walking test. Investigations were performed at baseline, 1 week after the patient received shoes with orthoses and 6 months later. Results. Plantar pressures were significantly higher at painful than at non-painful foot areas. No differences in plantar pressure redistribution were found between the groups. Notable reduction of pain and improvement of activity (walking ability) was observed in both groups. Foot pain has moderate impact on the walking ability of RA patients. Conclusions. The study showed no clear advantage of functional foot orthoses over UM.

Phantom motor execution facilitated by machine learning and augmented reality as treatment for phantom limb pain: a single group, clinical trial in patients with chronic intractable phantom limb pain

BACKGROUND Phantom limb pain is a debilitating condition for which no effective treatment has been found. We hypothesised that re-engagement of central and peripheral circuitry involved in motor execution could reduce phantom limb pain via competitive plasticity and reversal of cortical reorganisation. METHODS Patients with upper limb amputation and known chronic intractable phantom limb pain were recruited at three clinics in Sweden and one in Slovenia. Patients received 12 sessions of phantom motor execution using machine learning, augmented and virtual reality, and serious gaming. Changes in intensity, frequency, duration, quality, and intrusion of phantom limb pain were assessed by the use of the numeric rating scale, the pain rating index, the weighted pain distribution scale, and a study-specific frequency scale before each session and at follow-up interviews 1, 3, and 6 months after the last session. Changes in medication and prostheses were also monitored. Results are reported using descriptive statistics and analysed by non-parametric tests. The trial is registered at ClinicalTrials.gov, number NCT02281539. FINDINGS Between Sept 15, 2014, and April 10, 2015, 14 patients with intractable chronic phantom limb pain, for whom conventional treatments failed, were enrolled. After 12 sessions, patients showed statistically and clinically significant improvements in all metrics of phantom limb pain. Phantom limb pain decreased from pre-treatment to the last treatment session by 47% (SD 39; absolute mean change 1·0 [0·8]; p=0·001) for weighted pain distribution, 32% (38; absolute mean change 1·6 [1·8]; p=0·007) for the numeric rating scale, and 51% (33; absolute mean change 9·6 [8·1]; p=0·0001) for the pain rating index. The numeric rating scale score for intrusion of phantom limb pain in activities of daily living and sleep was reduced by 43% (SD 37; absolute mean change 2·4 [2·3]; p=0·004) and 61% (39; absolute mean change 2·3 [1·8]; p=0·001), respectively. Two of four patients who were on medication reduced their intake by 81% (absolute reduction 1300 mg, gabapentin) and 33% (absolute reduction 75 mg, pregabalin). Improvements remained 6 months after the last treatment. INTERPRETATION Our findings suggest potential value in motor execution of the phantom limb as a treatment for phantom limb pain. Promotion of phantom motor execution aided by machine learning, augmented and virtual reality, and gaming is a non-invasive, non-pharmacological, and engaging treatment with no identified side-effects at present. FUNDING Promobilia Foundation, VINNOVA, Jimmy Dahlstens Fond, PicoSolve, and Innovationskontor Väst.