Carolina S. Ballert

A Systematic Literature Review of Outcome Measures for Upper Extremity Function Using the International Classification of Functioning, Disability, and Health as Reference

To provide information regarding the (1) responsiveness and reliability of different outcome measures used with persons who have impairments in upper extremity function and (2) their content validity based on the International Classification of Functioning, Disability, and Health (ICF).

Setting up a cohort study on functioning: deciding what to measure

The objectives of this article were to (1) answer the question of what to measure in a cohort study in which the main focus is the understanding of functioning over time for a specific population and to (2) describe the process of determining what to measure using a theory-informed selection of domains of functioning based on the International Classification of Functioning, Disability and Health (ICF). The Swiss Spinal Cord Injury Cohort Study, a cohort study being carried out in Switzerland for a population of persons with spinal cord injury, was used as an example. A set of domains for the Swiss Spinal Cord Injury Cohort Study was identified demonstrating the application of the methodology. This set consisted of 45 categories of the ICF. Defining what to measure using the ICF is a valuable technique for the cohort researcher because it guarantees comparability of data and comprehensiveness of scope, enhancing the prospects of the study results being understood and is consequently used by health professionals as well as in other contexts, such as in health and social policy.

PARADISE 24: A measure to assess the impact of brain disorders on people's lives

Objective To construct a metric of the impact of brain disorders on people’s lives, based on the psychosocial difficulties (PSDs) that are experienced in common across brain disorders. Study Design Psychometric study using data from a cross-sectional study with a convenience sample of 722 persons with 9 different brain disorders interviewed in four European countries: Italy, Poland, Spain and Finland. Questions addressing 64 PSDs were first reduced based on statistical considerations, patient’s perspective and clinical expertise. Rasch analyses for polytomous data were also applied. Setting In and outpatient settings. Results A valid and reliable metric with 24 items was created. The infit of all questions ranged between 0.7 and 1.3. There were no disordered thresholds. The targeting between item thresholds and persons’ abilities was good and the person-separation index was 0.92. Persons’ abilities were linearly transformed into a more intuitive scale ranging from zero (no PSDs) to 100 (extreme PSDs). Conclusion The metric, called PARADISE 24, is based on the hypothesis of horizontal epidemiology, which affirms that people with brain disorders commonly experience PSDs. This metric is a useful tool to carry out cardinal comparisons over time of the magnitude of the psychosocial impact of brain disorders and between persons and groups in clinical practice and research.

TOWARD STANDARDIZED REPORTING FOR A COHORT STUDY ON FUNCTIONING: THE SWISS SPINAL CORD INJURY COHORT STUDY

OBJECTIVE Functioning is an important outcome to measure in cohort studies. Clear and operational outcomes are needed to judge the quality of a cohort study. This paper outlines guiding principles for reporting functioning in cohort studies and addresses some outstanding issues. DESIGN Principles of how to standardize reporting of data from a cohort study on functioning, by deriving scores that are most useful for further statistical analysis and reporting, are outlined. The Swiss Spinal Cord Injury Cohort Study Community Survey serves as a case in point to provide a practical application of these principles. METHODS AND RESULTS Development of reporting scores must be conceptually coherent and metrically sound. The International Classification of Functioning, Disability and Health (ICF) can serve as the frame of reference for this, with its categories serving as reference units for reporting. To derive a score for further statistical analysis and reporting, items measuring a single latent trait must be invariant across groups. The Rasch measurement model is well suited to test these assumptions. CONCLUSION Our approach is a valuable guide for researchers and clinicians, as it fosters comparability of data, strengthens the comprehensiveness of scope, and provides invariant, interval-scaled data for further statistical analyses of functioning.

Metric properties of the Spinal Cord Independence Measure -: Self report in a community survey

OBJECTIVE The Spinal Cord Independence Measure - Self Report (SCIM-SR) is a self-report instrument for assessing functional independence of persons with spinal cord injury. This study examined the internal construct validity and reliability of the SCIM-SR, when administered in a community survey, using the Rasch measurement model. METHODS Rasch analysis of data from 1,549 individuals with spinal cord injury who completed the SCIM-SR. RESULTS In the initial analysis no fit to the Rasch model was achieved. Items were grouped into testlets to accommodate the substantial local dependency. Due to the differential item functioning for lesion level and degree, spinal cord injury-specific sub-group analyses were conducted. Fit to the Rasch model was then achieved for individuals with tetraplegia and complete paraplegia, but not for those with incomplete paraplegia. Comparability of ability estimates across sub-groups was attained by anchoring all sub-groups on a testlet. CONCLUSION The SCIM-SR violates certain assumptions of the Rasch measurement model, as shown by the local dependency and differential item functioning. However, an intermediate solution to achieve fit in 3 out of 4 spinal cord injury sub-groups was found. For the time being, therefore, it advisable to use this approach to compute Rasch-transformed SCIM-SR scores.

Perceived impact of environmental barriers on participation among people living with spinal cord injury in Switzerland

OBJECTIVE To describe the impact of environmental barriers perceived by people living with spinal cord injury in the Swiss community and to compare this across subpopulations. DESIGN Cross-sectional study. SUBJECTS A total of 1,549 participants in the community survey of the Swiss spinal cord injury Cohort study. METHODS The perceived impact of environmental barriers on participation was measured with the Nottwil Environmental Factors Inventory Short Form (NEFI-SF). Physical independence was measured with the Spinal Cord Independence Measure Self Report (SCIM-SR). Perceived barriers were compared across people with different demographic and lesion characteristics. Multivariable regression modelling applying fractional polynomials was used to evaluate the overall perceived impact of barriers in relation to demographics, spinal cord injury characteristics, and physical independence. RESULTS Most perceived barriers were climatic conditions and inaccessibility of public and private infrastructure. Older participants, those with longer time since injury and participants with complete lesions indicated more problems with access. Females reported more attitudinal barriers. Approximately one-third of participants with complete tetraplegia reported obstacles related to assistance with personal care. A higher level of physical independence was associated with fewer perceived barriers. CONCLUSION Despite living in a rich country with a well-developed social security system, many people with spinal cord injury in Switzerland experience participation restrictions due to environmental barriers; in particular women, people with non-traumatic spinal cord injury and limited physical independence.

Explanatory power does not equal clinical importance: study of the use of the Brief ICF Core Sets for Spinal Cord Injury with a purely statistical approach

Study design:Psychometric study analyzing the data of a cross-sectional, multicentric study with 1048 persons with spinal cord injury (SCI).Objective:To shed light on how to apply the Brief Core Sets for SCI of the International Classification of Functioning, Disability and Health (ICF) by determining whether the ICF categories contained in the Core Sets capture differences in overall health.Methods:Lasso regression was applied using overall health, rated by the patients and health professionals, as dependent variables and the ICF categories of the Comprehensive ICF Core Sets for SCI as independent variables.Results:The ICF categories that best capture differences in overall health refer to areas of life such as self-care, relationships, economic self-sufficiency and community life. Only about 25% of the ICF categories of the Brief ICF Core Sets for the early post-acute and for long-term contexts were selected in the Lasso regression and differentiate, therefore, among levels of overall health.Conclusion:ICF categories such as d570 Looking after one’s health, d870 Economic self-sufficiency, d620 Acquisition of goods and services and d910 Community life, which capture changes in overall health in patients with SCI, should be considered in addition to those of the Brief ICF Core Sets in clinical and epidemiological studies in persons with SCI.

Metric properties of the Utrecht Scale for Evaluation of Rehabilitation-Participation (USER-Participation) in persons with spinal cord injury living in Switzerland

OBJECTIVE To examine the metric properties of the Utrecht Scale for Evaluation of Rehabilitation-Participation (USER-Participation) in persons with spinal cord injury in Switzerland from a classical and item response theory perspective. DESIGN Cross-sectional survey. SUBJECTS Persons with spinal cord injury living in the Swiss community (n = 1,549). METHODS Score distributions and internal consistency were evaluated using Classical Test Theory. The Restrictions and Satisfaction scales were subjected to Rasch analysis. Anchored analyses were performed to account appropriately for items with structural missing. RESULTS Internal consistency was good for the Restrictions (α = 0.90) and Satisfaction scales (α = 0.90), but not for the Frequency scale (α = 0.65). Rasch analyses showed acceptable model fit for the Restrictions and Satisfaction scales after collapsing response categories of some items and merging some items into testlets. Differential item functioning was small. Anchoring allowed inclusion of the item work/education in the Restrictions scale and work/education and/or partner relationship in the Satisfaction scale. CONCLUSION The Restrictions and Satisfaction scales of the USER-Participation showed satisfactory metric properties. The Frequency scale showed fewer optimal properties, but nonetheless provides important additional information regarding participation. Conversion tables were performed to transform USER-Participation raw scores into a 0-100 interval scale using Rasch-based ability estimates for use in epidemiological studies.

Determinants of Psychosocial Difficulties Experienced by Persons with Brain Disorders: Towards a ‘Horizontal Epidemiology’ Approach

Background Persons with brain disorders experience significant psychosocial difficulties (PSD) in daily life, e.g. problems with managing daily routine or emotional lability, and the level of the PSD depends on social, physical and political environments, and psychologic-personal determinants. Our objective is to determine a brief set of environmental and psychologic-personal factors that are shared determinants of PSD among persons with different brain disorders. Methods Cross-sectional study, convenience sample of persons with either dementia, stroke, multiple sclerosis, epilepsy, migraine, depression, schizophrenia, substance dependence or Parkinson’s disease. Random forest regression and classical linear regression were used in the analyses. Results 722 subjects were interviewed in four European countries. The brief set of determinants encompasses presence of comorbidities, health status appraisal, stressful life events, personality changes, adaptation, self-esteem, self-worth, built environment, weather, and health problems in the family. Conclusions The identified brief set of common determinants of PSD can be used to support the implementation of cross-cutting interventions, social actions and policy tools to lower PSD experienced by persons with brain disorders. This set complements a recently proposed reliable and valid direct metric of PSD for brain disorders called PARADISE24.

Psychometric properties of the Nottwil Environmental Factors Inventory Short Form

OBJECTIVES To examine the psychometric properties of the Nottwil Environmental Factors Inventory Short Form using Rasch analysis; to determine its construct validity and internal consistency; and to develop a metric for scoring. DESIGN Cross-sectional psychometric study. Construct validity of the Nottwil Environmental Factors Inventory Short Form, including model fit, person and item fit, local item dependence, dimensionality, and differential item functioning (DIF), was investigated with Rasch analysis. Internal consistency was assessed with Cronbach alpha and item-total correlations. SETTING Community. PARTICIPANTS Swiss residents aged >16 years and living with traumatic or nontraumatic spinal cord injury (SCI) (N=1549). INTERVENTIONS Not applicable. MAIN OUTCOME MEASURE The Nottwil Environmental Factors Inventory Short Form, a 14-item questionnaire developed to assess perceived impact of environmental barriers on participation. RESULTS Local dependencies between items addressing a similar content could be solved by creating a testlet. With 1 testlet there was strong evidence for unidimensionality of the Nottwil Environmental Factors Inventory Short Form. Although person-item targeting revealed a floor effect, indicating few perceived environmental barriers to participation in the Swiss SCI population, the item fit was good. Only a few items presented DIF. The Nottwil Environmental Factors Inventory Short Form showed good internal consistency (α=.82). CONCLUSIONS This psychometric analysis supports the use of the Nottwil Environmental Factors Inventory Short Form to evaluate perceived environmental barriers to participation in persons with SCI living in the community.