How Shape Perception Works, in Two Dimensions and Three Dimensions.

The ventral visual pathway transforms retinal images into neural representations that support object understanding, including exquisite appreciation of precise 2D pattern shape and 3D volumetric shape. We articulate a framework for understanding the goals of this transformation and how they are achieved by neural coding at successive ventral pathway stages. The critical goals are (a) radical compression to make shape information communicable across axonal bundles and storable in memory, (b) explicit coding to make shape information easily readable by the rest of the brain and thus accessible for cognition and behavioral control, and (c) representational stability to maintain consistent perception across highly variable viewing conditions. We describe how each transformational step in ventral pathway vision serves one or more of these goals. This three-goal framework unifies discoveries about ventral shape processing into a neural explanation for our remarkable experience of shape as a vivid, richly detailed aspect of the natural world.

Nationwide implementation of lenalidomide maintenance in multiple myeloma: A retrospective, real-world study.

Lenalidomide maintenance (LM) has shown benefit in progression-free survival (PFS) and overall survival (OS) in clinical trials. LM is the recommended standard of care in patients with newly diagnosed multiple myeloma (MM) after high-dose melphalan and autologous stem cell transplantation (HDM-ASCT). In Denmark, LM has been approved and publicly funded for all patients treated with HDM-ASCT since June 2019. Patients with newly diagnosed MM treated with their first HDM-ASCT between June 2019 and March 2022 were included and followed until data cut-off in June 2023. To compare outcomes, a historical pre-LM cohort from the Danish MM Registry, consisting of 364 MM patients treated with HDM-ASCT between June 2015 and June 2019, was used. Among 364 patients treated with HDM-ASCT after June 2019, 22.3% received consolidation therapy and 3.7% underwent tandem HDM-ASCT. During follow-up, 297 patients (81.6%) initiated maintenance therapy, with 277 (76.1%) receiving LM. Overall, 145 patients (52.3%) discontinued LM most commonly due to toxicity 75 (51.7%), with fatigue (30.7%), cytopenia (25.3%), and neuropathy (17.3%) being the main reasons. In a 6-month landmark analysis, early discontinuation did not negatively impact PFS or OS. The LM cohort had similar PFS, and OS compared to the pre-LM cohort. The 3-year PFS and OS rates in the LM cohort were 61% and 86%, respectively, while the pre-LM cohort had a 3-year PFS of 55% and a 3-year OS of 89%. In conclusion, the introduction of LM as a nationwide treatment option in Denmark did not lead to improved clinical outcomes.

Simulation-based education in ultrasound - diagnostic and interventional abdominal focus. / Simulationsbasierte Ausbildung im Ultraschall ­ Fokus auf der diagnostischen und interventionellen Abdomen-Sonografie.

Simulation-based training (SBT) is increasingly acknowledged worldwide and has become a popular tool for ultrasound education. Ultrasound simulation involves the use of technology and software to create a virtual training setting. Simulation-based training allows healthcare professionals to learn, practice, and improve their ultrasound imaging skills in a safe learning-based environment. SBT can provide a realistic and focused learning experience that creates a deep and immersive understanding of the complexity of ultrasound, including enhancing knowledge and confidence in specific areas of interest. Abdominal ultrasound simulation is a tool to increase patient safety and can be a cost-efficient training method. In this paper, we provide an overview of various types of abdominal ultrasound simulators, and the benefits, and challenges of SBT. We also provide examples of how to develop SBT programs and learning strategies including mastery learning. In conclusion, the growing demand for medical imaging increases the need for healthcare professionals to start using ultrasound simulators in order to keep up with the rising standards.

Reliability of interview-based ADL ability measures in older adults obtained by occupational therapists, physical therapists, and nursing staff.

Purpose: To examine the reliability of ADL interview (ADL-I) ability measures when administered by different health professionals (HPs).Materials and methods:Older adults with stable ADL ability were invited to participate in three ADL-I interviews, administered by occupational therapists (OTs), physical therapists (PTs), and nursing staff (NS), respectively. Methods based on classic and modern test theory were applied.Results:Overall, n = 36 older adults and n = 11 HPs participated. Intraclass Correlation Coefficients were acceptable for research purposes (> 0.7), but not for clinical use. Mean differences in ADL ability measures were significant when comparing measures based on interviews by OTs to measures based on interviews by PTs and NS. Further, in 25 to 47% of the individuals, ADL-I ability measures differed significantly across HPs. Limits of Agreement revealed that measures based on interviews by OTs were systematically lower compared to measures based on interviews by PTs and NS. Four ADL-I items displayed Differential Item Functioning based on HP.Conclusion:When using the ADL-I, it is recommended to only involve one profession, to increase the reliability of measures. Results highlight the importance of evaluating reliability of measures based on instruments administered across HPs before implementation in rehabilitation practice and research.

Evaluations of activities of daily living (ADL) ability conducted in rehabilitation practice by different health professionals may not generate comparable results.When using the ADL-Interview, it is recommended to only involve one profession, to increase reliability of measures.The results of the present study highlight the importance of evaluating if ADL instruments can produce reliable measures in terms of both interrater reliability and measurement error.

Qualitative realist evaluation of an occupational therapy intervention programme (ABLE), addressing ability to perform activities of daily living among persons with chronic conditions.

BACKGROUND: Chronic conditions are associated with problems related to performance of activities of daily living (ADL) stressing a need to develop and evaluate intervention programmes addressing such problems. Hence, the ABLE programme was developed, and its feasibility evaluated. Implementing intervention programmes in community-based rehabilitation settings requires understanding of how the programme works in various contexts. Applying a realist evaluation approach, the aim of this study was to identify and evaluate interactions between contexts, mechanisms, and outcomes in the ABLE 2.0, to confirm, refine, or reject aspects of the initial programme theory. METHODS: Realist evaluation using qualitative data collected in the ABLE 2.0 randomised controlled trial (n = 78). Based on the ABLE 2.0 initial programme theory, qualitative realist interviews were conducted among receivers (n = 8) and deliverers (n = 3) of the ABLE 2.0 in a Danish municipality. Transcripts were coded, and context-mechanism-outcome configurations were extracted and grouped into contiguous themes. Results were then held up against the initial programme theory. RESULTS: Four contiguous themes were identified including a total of n = 28 context-mechanism-outcome configurations: building a foundation for the entire intervention; establishing the focus for further intervention; identifying and implementing relevant compensatory solutions; and re-evaluating ADL ability to finalise intervention. Overall, the ABLE 2.0 initial programme theory was confirmed. The evaluation added information on core facilitating mechanisms including active involvement of the client in the problem-solving process, a collaborative working relationship, mutual confidence, and a consultative occupation-based process using compensatory solutions. Several contextual factors were required to activate the desired mechanisms in terms of supportive management, referral procedures encouraging the problem-solving process, delivery in the client's home, skilled occupational therapists, and clients feeling ready for making changes. CONCLUSIONS: The ABLE 2.0 represents a coherent problem-solving occupational therapy process, applicable across sex, age, and diagnoses with the potential to enhance ADL ability among persons with chronic conditions, when delivered as part of community-based rehabilitation services. Knowledge about the interactions between contextual factors, mechanisms, and outcomes in the ABLE 2.0 is central in case of future implementation of the programme in community-based rehabilitation settings. TRIAL REGISTRATION: The trial was prospectively registered on www. CLINICALTRIALS: gov (registration date: 05/03/2020; identifier: NCT04295837 ) prior to data collection that occurred between August 2020 and October 2021.

The Cousa objective: a long-working distance air objective for multiphoton imaging in vivo.

Multiphoton microscopy can resolve fluorescent structures and dynamics deep in scattering tissue and has transformed neural imaging, but applying this technique in vivo can be limited by the mechanical and optical constraints of conventional objectives. Short working distance objectives can collide with compact surgical windows or other instrumentation and preclude imaging. Here we present an ultra-long working distance (20 mm) air objective called the Cousa objective. It is optimized for performance across multiphoton imaging wavelengths, offers a more than 4 mm2 field of view with submicrometer lateral resolution and is compatible with commonly used multiphoton imaging systems. A novel mechanical design, wider than typical microscope objectives, enabled this combination of specifications. We share the full optical prescription, and report performance including in vivo two-photon and three-photon imaging in an array of species and preparations, including nonhuman primates. The Cousa objective can enable a range of experiments in neuroscience and beyond.

Transcriptional Control of Neocortical Size and Microcephaly.

The mammalian neocortex differs vastly in size and complexity between mammalian species, yet the mechanisms that lead to an increase in brain size during evolution are not known. We show here that two transcription factors coordinate gene expression programs in progenitor cells of the neocortex to regulate their proliferative capacity and neuronal output in order to determine brain size. Comparative studies in mice, ferrets and macaques demonstrate an evolutionary conserved function for these transcription factors to regulate progenitor behaviors across the mammalian clade. Strikingly, the two transcriptional regulators control the expression of large numbers of genes linked to microcephaly suggesting that transcriptional deregulation as an important determinant of the molecular pathogenesis of microcephaly, which is consistent with the finding that genetic manipulation of the two transcription factors leads to severe microcephaly. Summary: The neocortex varies in size and complexity among mammals due to the tremendous variability in the number and diversity of neuronal subtypes across species 1,2 . The increased cellular diversity is paralleled by the expansion of the pool of neocortical progenitors 2-5 and the emergence of indirect neurogenesis 6 during brain evolution. The molecular pathways that control these biological processes and are disrupted in neurological and psychiatric disorders remain largely unknown. Here we show that the transcription factors BRN1 (POU3F3) and BRN2 (POU3F2) act as master regulators of the transcriptional programs in progenitors linked to neuronal specification and neocortex expansion. Using genetically modified lissencephalic and gyrencephalic animals, we found that BRN1/2 establish transcriptional programs in neocortical progenitors that control their proliferative capacity and the switch from direct to indirect neurogenesis. Functional studies in genetically modified mice and ferrets show that BRN1/2 act in concert with NOTCH and primary microcephaly genes to regulate progenitor behavior. Analysis of transcriptomics data from genetically modified macaques provides evidence that these molecular pathways are conserved in non-human primates. Our findings thus establish a mechanistic link between BRN1/2 and genes linked to microcephaly and demonstrate that BRN1/2 are central regulators of gene expression programs in neocortical progenitors critical to determine brain size during evolution.

Object representation in a gravitational reference frame.

When your head tilts laterally, as in sports, reaching, and resting, your eyes counterrotate less than 20%, and thus eye images rotate, over a total range of about 180°. Yet, the world appears stable and vision remains normal. We discovered a neural strategy for rotational stability in anterior inferotemporal cortex (IT), the final stage of object vision in primates. We measured object orientation tuning of IT neurons in macaque monkeys tilted +25 and -25° laterally, producing ~40° difference in retinal image orientation. Among IT neurons with consistent object orientation tuning, 63% remained stable with respect to gravity across tilts. Gravitational tuning depended on vestibular/somatosensory but also visual cues, consistent with previous evidence that IT processes scene cues for gravity's orientation. In addition to stability across image rotations, an internal gravitational reference frame is important for physical understanding of a world where object position, posture, structure, shape, movement, and behavior interact critically with gravity.

Effectiveness of an individualised occupational therapy intervention programme (ABLE) using adaptational strategies on activities of daily living among persons with chronic conditions: A randomised controlled trial (RCT).

OBJECTIVE: Compare the effectiveness of a problem-solving, individualised, home-based occupational therapy intervention (ABLE 2.0), to usual occupational therapy, on activities of daily living (ADL) ability in persons with chronic conditions. DESIGN: A single-centre, double-blinded, randomised controlled trial with 10- and 26-week follow-up. SETTING: A Danish municipality. SUBJECTS: Persons with chronic conditions experiencing problems performing ADL tasks (n = 80). INTERVENTIONS: ABLE 2.0 was compared with usual occupational therapy. MAIN MEASURES: Coprimary outcomes were self-reported ADL ability (ADL-Interview Performance) and observed ADL motor ability (Assessment of Motor and Process Skills) at Week 10. Secondary outcomes were self-reported ADL ability (ADL-Interview Performance) and observed ADL motor ability (Assessment of Motor and Process Skills) at Week 26, and perceived satisfaction with ADL ability (ADL-Interview Satisfaction) and observed ADL process ability (Assessment of Motor and Process Skills) at Weeks 10 and 26. RESULTS: In total, 78 persons were randomly assigned: 40 to usual occupational therapy and 38 to ABLE 2.0. No statistically significant nor clinically relevant difference between group mean changes in primary outcomes was identified from baseline to Week 10 (ADL-Interview Performance [-0.16; 95% CI: -0.38 to 0.06] and Assessment of Motor and Process Skills ADL motor ability [-0.1; 95% CI: -0.3 to 0.1]). At Week 26, a statistically significant and clinically relevant difference was found in Assessment of Motor and Process Skills ADL motor ability (LS mean change: -0.3; 95% CI: -0.5 to -0.1) between groups. CONCLUSION: ABLE 2.0 was effective in improving observed ADL motor ability at 26 weeks.

Clinical utility of the Danish version of the Self-Assessment of Modes Questionnaire (D-SAMQ).

BACKGROUND: The the Self-Assessment of Modes Questionnaire (SAMQ) has been translated into Danish and culturally adapted (D-SAMQ), and aspects of validity and reliability have also been evaluated. However, no knowledge about the clinical utility of the D-SAMQ exists. AIMS/OBJECTIVES: The aims were to investigate the clinical utility of the D-SAMQ among Danish occupational therapists (OTs) and occupational therapy students (OTSs), and to determine differences in perceived clinical utility between the two groups. MATERIAL AND METHODS: Data was collected using an online survey consisting of 17 questions related to four dimensions of clinical utility; appropriateness, accessibility, practicability, and acceptability. RESULTS: A total of 25 OTs and 41 OTSs participated. The clinical utility was perceived to be high across all questions related to the four dimensions. No statistically significant differences were found between OTs and OTSs in any of the four dimensions. CONCLUSIONS AND SIGNIFICANCE: The D-SAMQ is ready for use in occupational therapy practice, education, and research. D-SAMQ can be used to gain insight into own therapeutic style. This insight serves as a basis for facilitating therapeutic relationships with the clients during the process of enabling engagement in occupation.

Assessment of motor and process skills in Danish occupational therapy practice.

BACKGROUND: The demand for employment of standardized evaluations is increasing. In Denmark, approximately 25% of all occupational therapists (OTs) are trained to use the standardized occupational therapy instrument Assessment of Motor and Process Skills (AMPS). AIMS: To investigate the use of AMPS within Danish occupational therapy practice and determine factors supporting or hindering the use. MATERIAL AND METHODS: An online cross-sectional survey was conducted among OTs from various settings. RESULTS: Overall, 844 calibrated OTs participated in the survey. Of these, 540 (64%) met the inclusion criteria and 486 (90%) completed the questionnaire. Forty percent of the participants used the AMPS in a standardized way during a one-month period and 56% reported being dissatisfied with the low number of AMPS evaluations completed. Five supporting and nine hindering factors were found to significantly influence the use of standardized AMPS evaluations. CONCLUSIONS/SIGNIFICANCE: Despite demands for standardized evaluations, the AMPS is not regularly used in a standardized way within Danish occupational therapy practice. Use of AMPS in clinical practice seems to be facilitated by an acknowledgement from the management and the OT's ability to develop habits and routines. Time restraints were reported, however, time to conduct evaluations was not a statistically significant influencing factor.

Reliability and validity of the Danish version of the Self-Assessment of Modes Questionnaire.

BACKGROUND: The Self-Assessment of Modes Questionnaire (SAMQ) is developed to help therapists identify their preferred use of modes when interacting with clients in clinical practice. A Danish translation of the SAMQ has been developed (D-SAMQ). To provide a robust instrument for occupational therapy practice and research, evaluation of the psychometric properties of the D-SAMQ is needed. OBJECTIVES: The study aims to evaluate test-retest reliability, measurement error and content validity in terms of cultural relevance of the D-SAMQ. MATERIAL AND METHODS: Danish occupational therapists were recruited to represent diverse clinical settings and to work with various age groups. The D-SAMQ consists of 20 clinical cases. A repeated measures design was employed with evaluation of content validity at the second timepoint. The Content Validity Index and Kappa statistics were employed. RESULTS: In most cases (n = 12, 60%) agreement (test-retest reliability and measurement error) was moderate or strong. Also, there was a moderate (n = 6 cases, 30%), strong (n = 4 cases, 20%) or almost perfect agreement (n = 10 cases, 50%) on the cultural relevance of the cases. CONCLUSIONS: Acceptable test-retest reliability, measurement error and content validity were found. The SAMQ may support occupational therapists to adapt their therapeutic style to meet the needs of the clients.

Quality of ADL task performance in persons with schizophrenia: Looking beyond independence.

BACKGROUND: Persons with schizophrenia may experience decreased ability to perform activities of daily living (ADL) indicated by need for assistance in everyday life. Others are independent, but their quality of ADL task performance in terms of effort and efficiency may still be impacted. AIMS/OBJECTIVES: The overall purpose of this study was to explore the quality of ADL task performance in subgroups with schizophrenia (independent/needing assistance). MATERIALS AND METHODS: Participants were in- and outpatients at a Psychiatric Hospital diagnosed with schizophrenia (n = 83). Their quality of ADL task performance was evaluated using the Assessment of Motor and Process Skills (AMPS). Evaluations were conducted at the hospital. Two subgroups (A: independent and B: needing assistance) were created based on AMPS ADL ability measures. RESULTS: The majority in both subgroups had AMPS ADL ability measures within the risk zones. Further, the majority in subgroup A had ADL ability measures within age expectations but below mean for well persons of the same age. Both ineffective motor and process skills were identified in both subgroups. CONCLUSIONS/SIGNIFICANCE: Occupational therapy is indicated for persons with schizophrenia, both for independent persons and for persons needing assistance. This is to prevent decline in or to enhance ADL ability.

Danish translation, adaptation and initial validation of the clinical assessment of modes questionnaires.

BACKGROUND: The Clinical Assessment of Modes questionnaires (CAMQs) determine clients' preferential modes for therapy (CAM-C1), clients' perception of modes used by the occupational therapist (OTs) during therapy (CAM-C2), or modes the OTs believed to have used (CAM-T). Access to valid CAMQs for Danish OTs and clients required a rigorous translation and cultural adaptation process. OBJECTIVES: To translate and culturally adapt the CAMQs into Danish, examining face validity in a Danish context. MATERIAL AND METHODS: A 10-step guideline for the process of translating and culturally adapting questionnaires was followed. Steps 1-6 included translation into Danish, steps 7-8 involved cognitive debriefing interviews and validation based on the Content Validity Index (CVI) analyzed using Kappa statistics. Steps 9-10 finalized the process. RESULTS: CAMQs were translated into Danish. Based on cognitive debriefing interviews and CVIs involving 15 clients and 7 OTs, modifications regarding titles, layouts, instructions, wording and response categories were performed in all Danish CAMQs. The Item CVI and the modified kappa revealed that most participants had a high level of agreement on the cultural relevance. CONCLUSIONS AND SIGNIFICANCE: Translated versions of the CAMQs have been culturally adapted into Danish. The current Danish versions seem culturally relevant and useable in Danish occupational therapy.

Cell-specific regulation of gene expression using splicing-dependent frameshifting.

Precise and reliable cell-specific gene delivery remains technically challenging. Here we report a splicing-based approach for controlling gene expression whereby separate translational reading frames are coupled to the inclusion or exclusion of mutated, frameshifting cell-specific alternative exons. Candidate exons are identified by analyzing thousands of publicly available RNA sequencing datasets and filtering by cell specificity, conservation, and local intron length. This method, which we denote splicing-linked expression design (SLED), can be combined in a Boolean manner with existing techniques such as minipromoters and viral capsids. SLED can use strong constitutive promoters, without sacrificing precision, by decoupling the tradeoff between promoter strength and selectivity. AAV-packaged SLED vectors can selectively deliver fluorescent reporters and calcium indicators to various neuronal subtypes in vivo. We also demonstrate gene therapy utility by creating SLED vectors that can target PRPH2 and SF3B1 mutations. The flexibility of SLED technology enables creative avenues for basic and translational research.

Correction: Hands-On Time in Simulation-Based Ultrasound Training - A Dose-Related Response Study.

[This corrects the article DOI: 10.1055/a-1795-5138.].

Hands-On Time in Simulation-Based Ultrasound Training - A Dose-Related Response Study.

Purpose Point of care ultrasound (POCUS) is widely used, but the sensitivity and specificity of the findings are highly user-dependent. There are many different approaches to ultrasound training. The aim of this study was to explore the effects of hands-on practice when learning POCUS. Methods Junior doctors with no or limited ultrasound experience were included in the study and divided into three groups. They all completed a Focused Assessment with Sonography for Trauma (FAST) course with different amounts of hands-on practice: 40 minutes (n=67), 60 minutes (n=12), and 90 minutes of hands-on time (n=27). By the end of the course, they all completed a previously validated test. Results More hands-on time improved the mean test scores and decreased the test time. The scores of the 40-, 60-, and 90-minute groups were 11.6 (SD 2.1), 12.8 (SD 2.5), and 13.7 (SD 2.5), respectively (p<0.001). The 90-minute group completed the test significantly faster than the other two groups (20 versus 26 minutes, p=0.003). A large inter-individual variation was seen. Conclusion The necessary amount of hands-on training is unknown. This study demonstrates that performance increases with prolonged hands-on time but the inter-individual variation among trainees is very large, thereby making it impossible to define the "optimal" time. This supports the use of the concept of mastery learning where each individual trainee can continue training until proficiency is reached.

Fostering Change Through Occupation-Based Intervention: An International Joint Group Concept Mapping Study.

Further consolidation and clarity regarding occupation as a means to foster change in interventions are needed. The study aimed to utilize the knowledge of occupational scholars to systematically determine what is required to use occupation as means to foster change within occupation-based interventions and to generate a conceptual model from those results. Group Concept Mapping involved the following: preparation, generation of ideas, structuring of statements, data analysis, interpretation of maps, and development of conceptual model. Fifty-two international occupational scholars brainstormed 125 ideas. A cluster rating map with nine clusters posed the foundation for a conceptual model with seven themes, namely, artful use of occupation, evidence-based use of occupation, collaboration to promote occupation, coordinating intervention fit, client factors, sociocultural context, and structural influences. The conceptual model, capturing dimensions and dynamics required for using occupation to foster change, may guide future research into occupation-based interventions.

Evaluating a complex intervention addressing ability to perform activities of daily living among persons with chronic conditions: study protocol for a randomised controlled trial (ABLE).

INTRODUCTION: The need to develop and evaluate interventions, addressing problems performing activities of daily living (ADL) among persons with chronic conditions, is evident. Guided by the British Medical Research Council's guidance on how to develop and evaluate complex interventions, the occupational therapy programme (A Better everyday LifE (ABLE)) was developed and feasibility tested. The aim of this protocol is to report the planned design and methods for evaluating effectiveness, process and cost-effectiveness of the programme. METHODS AND ANALYSIS: The evaluation is designed as a randomised controlled trial with blinded assessors and investigators. Eighty participants with chronic conditions and ADL problems are randomly allocated to ABLE or usual occupational therapy. Data for effectiveness and cost-effectiveness evaluations are collected at baseline (week 0), post intervention (week 10) and follow-up (week 26). Coprimary outcomes are self-reported ADL ability (ADL-Interview (ADL-I) performance) and observed ADL motor ability (Assessment of Motor and Process Skills (AMPS)). Secondary outcomes are perceived satisfaction with ADL ability (ADL-I satisfaction); and observed ADL process ability (AMPS). Explorative outcomes are occupational balance (Occupational Balance Questionnaire); perceived change (Client-Weighted Problems Questionnaire) and general health (first question of the MOS 36-item Short Form Survey Instrument). The process evaluation is based on quantitative data from registration forms and qualitative interview data, collected during and after the intervention period. A realist evaluation approach is applied. A programme theory expresses how context (C) and mechanisms (M) in the programme may lead to certain outcomes (O), in so-called CMO configurations. Outcomes in the cost-effectiveness evaluation are quality-adjusted life years (EuroQool 5-dimension) and changes in ADL ability (AMPS, ADL-I). Costs are estimated from microcosting and national registers. ETHICS AND DISSEMINATION: Danish Data Protection Service Agency approval: Journal-nr.: P-2020-203. The Ethical Committee confirmed no approval needed: Journal-nr.: 19 045 758. Dissemination for study participants, in peer-reviewed journals and conferences. TRIAL REGISTRATION NUMBER: NCT04295837.

Measuring self-reported ability to perform activities of daily living: a Rasch analysis.

BACKGROUND: Since the number of persons diagnosed with multi-morbidity is increasing, there is a need for generic instruments to be able to assess, measure and compare ADL ability across diagnoses. Accordingly, the ADL-Interview (ADL-I) was developed to be used in rehabilitation research and clinical practice. The aim of this study was to investigate if the ADL-I can be used to provide valid and reliable ADL ability measures across gender and diagnostic groups. METHODS: ADL-I data were extracted from an existing research database on persons with chronic conditions including medical, rheumatological, oncological, neurological, geriatric and psychiatric diagnoses. Data were analysed based on Rasch Measurement methods to examine: the psychometric properties of the rating scale; ADL item and person fit to the Rasch model; if the difficulty of the ADL tasks differs across gender and diagnostic groups, and if the ADL-I provides precise and reliable measures of ADL ability. RESULTS: Data on n = 2098 persons were included in the final analysis. Initial evaluation of the 0-3 rating scale revealed threshold disordering between categories 1 and 2. After removal of 16 underfitting items, the variance explained by the Rasch dimension increased from 54.3 to 58.0%, thresholds were ordered, but the proportion of persons with misfitting ADL-I measures increased slightly from 8.7 to 9.1%. The person separation index improved slightly from 2.75 to 2.99 (reliability = 0.90). Differential test function analysis, however, supported that the 16 underfitting items did not represent a threat to the measurement system. Similarly, ADL items displaying differential item functioning across gender and diagnoses did not represent a threat to the measurement system. The ADL items and participants were well distributed along the scale, with item and person measures well targeted to each other, indicating a small ceiling effect and no floor effect. CONCLUSIONS: The study results overall suggest that the ADL-I is producing valid and reliable measures across gender and diagnostic groups among persons within a broad range of ADL ability, providing evidence to support generic use of the ADL-I. TRIAL REGISTRATION: N/A.