Cristina Bostan
Ludwig Maximilian University of Munich
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Featured researches published by Cristina Bostan.
Developmental Medicine & Child Neurology | 2012
Nora Fayed; Olaf Kraus de Camargo; Elizabeth Kerr; Peter Rosenbaum; Ankita Dubey; Cristina Bostan; Markus Faulhaber; Parminder Raina; Alarcos Cieza
Aim Our aims were to (1) describe the conceptual basis of popular generic instruments according to World Health Organization (WHO) definitions of functioning, disability, and health (FDH), and quality of life (QOL) with health‐related quality of life (HRQOL) as a subcomponent of QOL; (2) map the instruments to the International Classification of Functioning, Disability and Health (ICF); and (3) provide information on how the analyzed instruments were used in the literature. This should enable users to make valid choices about which instruments have the desired content for a specific context or purpose.
Annals of the Rheumatic Diseases | 2013
U. Kiltz; D. van der Heijde; Annelies Boonen; Alarcos Cieza; Gerold Stucki; Muhammad Asim Khan; Walter P. Maksymowych; Helena Marzo-Ortega; John D. Reveille; Simon Stebbings; Cristina Bostan; J. Braun
Objectives The burden of disease in patients with ankylosing spondylitis (AS) can be considerable. However, no agreement has been reached among expert members of Assessment of SpondyloArthritis International Society (ASAS) to define severity of AS. Based on the International Classification of Functioning, Disability and Health (ICF), a core set of items for AS has been selected to represent the entire spectrum of possible problems in functioning. Based on this, the objective of this study was to develop a tool to quantify health in AS, the ASAS Health Index. Methods First, based on a literature search, experts’ and patients’ opinion, a large item pool covering the categories of the ICF core set was generated. In several steps this item pool was reduced based on reliability, Rasch analysis and consensus building after two cross-sectional surveys to come up with the best fitting items representing most categories of the ICF core set for AS. Results After the first survey with 1754 patients, the item pool of 251 items was reduced to 82. After selection by an expert committee, 50 items remained which were tested in a second cross-sectional survey. The results were used to reduce the number of items to a final set of 17 items. This selection showed the best reliability and fit to the Rasch model, no residual correlation, and absence of consistent differential item function and a Person Separation Index of 0.82. Conclusions In this long sequential study, 17 items which cover most of the ICF core set were identified that showed the best representation of the health status of patients with AS. The ASAS Health Index is a linear composite measure which differs from other measures in the public domain.
Quality of Life Research | 2011
Nora Fayed; Vero Schiariti; Cristina Bostan; Alarcos Cieza; Anne F. Klassen
PurposeThe impact of cancer on children can be assessed through various concepts including mental and physical health status and most significantly quality of life (QOL). It has been difficult to compare data collected through these instruments due to a lack of continuity or understanding of overlaps and gaps between them. To delineate the content of the most commonly used instruments in childhood cancer on an item-by-item basis, this study used standardized methods to link health information to the International Classification of Functioning, Disability, and Health (ICF) as well as World Health Organization (WHO) standard definitions of health and quality of life.MethodMEDLINE, CINAHL, EMBASE, PsycINFO, Cancerlit, and Sociological Abstracts were searched from the inception of each database to June 15th, 2009 for health status and quality of life instruments. The six most common cancer-specific and generic instruments employed in primary research in childhood cancer were analyzed on an item-by-item basis by two content assessors specializing in ICF linking and WHO definitions of health and QOL, using a standardized iterative technique developed at the ICF Research Branch.ResultsWe report the extent to which health status and QOL are represented in each instrument. Most measures emphasize a majority health status perspective according to WHO definitions of health. The generic instruments stress activities and participation domains over body functions or environment factors according to the ICF while cancer-specific instruments vary in their emphasis. Initial phase of coding agreement between assessors was in the substantial range (0.6–0.8 using Cohen’s kappa).ConclusionA comprehensive and systematic content analysis of the most commonly employed health status and QOL instruments was conducted for this review. Two criteria were described as follows: the perspectives of the instruments (i.e., health vs. QOL) and the health content (according to ICF components). No single instrument demonstrated an ideal balance of content characteristics according to these criteria, and thus, each must be considered carefully relative to one’s particular research or clinical evaluative purpose.
Topics in Stroke Rehabilitation | 2011
Beatrix Algurén; Cristina Bostan; Lennart Christensson; Bengt Fridlund; Alarcos Cieza
Abstract Purpose: To investigate the possibility of constructing a multiprofessional cross-cultural measure of functioning after stroke across categories of the International Classification of Functioning, Disability and Health (ICF). Method: Data on 757 stroke survivors from China, Germany, Italy, and Sweden, including ratings of 15 categories from the Brief ICF Core Set for stroke, were analyzed using the Rasch model. Unidimensionality, reliability, fit of the ICF categories to the model, ordering of response options of the ICF qualifier, and presence of differential item functioning (DIF) were studied. Results: Of the 15 ICF categories, response options for 7 categories were collapsed, 5 categories were deleted due to misfit, and 4 ICF categories showed DIF for country and were accordingly split into country-specific categories. The proposed final clinical measure consists of 20 ICF categories (6 categories were country-common) with an overall fit statistic of χ2180 = 184.87, P = .386, and a person separation index of r = 0.72, which indicates good reliability. Based on an individual’s functioning after stroke, the ratings across the different ICF categories can be summed on an interval scale ranging from 0 to 100. Conclusion: A construction of a cross-cultural clinical measure after stroke based on ICF categories across body functions, structures, and activities and participation was possible. With this kind of clinical measure, stroke survivors’ functional levels can be compared even across countries. Despite the promising results, further studies are necessary to develop definitive measures based on ICF categories.
American Journal of Physical Medicine & Rehabilitation | 2012
Cristina Bostan; Cornelia Oberhauser; Alarcos Cieza
ObjectiveThis study aimed to explore to what extent the data collected for patients with low back pain, breast cancer, and stroke, based on the International Classification of Functioning, Disability and Health (ICF) Checklist, reflect the hypothesized single latent dimension functioning and whether the ICF qualifier scale expresses a clearly defined ordered sequence of response options. DesignData including ratings of 56 ICF categories for low back pain, 54 for breast cancer, and 84 for stroke were analyzed using the Rasch model. ResultsFor each health condition, most of the ICF categories fit the Rasch model. In most of them, one or two of the four threshold estimates were reversed before collapsing the response options. The collapsing strategy 01122 was proposed. ConclusionsThe fit residual statistics showed that most of the ICF categories selected for each of the health conditions reflect the single latent variable functioning. The ordering of the ICF qualifier scale was not consistent with the intended order.
BMC Public Health | 2015
Cristina Bostan; Cornelia Oberhauser; Gerold Stucki; Jerome Bickenbach; Alarcos Cieza
BackgroundLived health and biological health are two different perspectives of health introduced by the International Classification of Functioning, Disability and Health (ICF). Since in the concept of lived health the impact of the environment on biological health is inherently included, it seems intuitive that when identifying the environmental determinants of health, lived health is the appropriate outcome. The Multilevel Item Response Theory (MLIRT) model has proven to be a successful method when dealing with the relation between a latent variable and observed variables. The objective of this study was to identify environmental factors associated with lived health when controlling for biological health by using the MLIRT framework.MethodsWe performed a psychometric study using cross-sectional data from the Spanish Survey on Disability, Independence and Dependency Situation. Data were collected from 17,303 adults living in 15,263 dwellings. The MLIRT model was used for each of the two steps of the analysis to: (1) calculate people’s biological health abilities and (2) estimate the association between lived health and environmental factors when controlling for biological health. The hierarchical structure of individuals in dwellings was considered in both models.ResultsSocial support, being able to maintain one’s job, the extent to which one’s health needs are addressed and being discriminated against due to one’s health problems were the environmental factors identified as associated with lived health. Biological health also had a strong positive association with lived health.ConclusionsThis study identified environmental factors associated with people’s lived health differences within and between dwellings according to the MLIRT-model approach. This study paves the way for the future implementation of the MLIRT model when analysing ICF-based data.
Journal of Rehabilitation Medicine | 2014
Cristina Bostan; Cornelia Oberhauser; Gerold Stucki; Jerome Bickenbach; Alarcos Cieza
OBJECTIVE To determine which environmental factors are associated with performance when controlling for capacity, using the International Classification of Functioning, Disability and Health (ICF). METHODS A psychometric study using a sample of 296 persons with musculoskeletal health conditions as a case in point. The following steps were carried out: (i) Rasch analyses created 2 interval measurement scales, capacity and performance, based on 22 Activities and Participation ICF categories that had been rated as capacity and performance. Capacity and performance scores, ranging from 0 (low level) to 100 (high level) were calculated; (ii) group lasso regression was used to identify the environmental factors associated with a persons performance when controlling for capacity. Gender, age and health condition were forced to remain in the model. RESULTS A capacity scale based on 16 ICF categories (rated as capacity) and a performance scale based on 18 categories (rated as performance) were created. Thirteen environmental factors ICF categories covering the physical, social, attitudinal and political environment were identified as highly associated with patients performance. CONCLUSION Using an exclusively statistical approach this study identified environmental factors associated with a persons performance.
BMC Public Health | 2014
Cristina Bostan; Cornelia Oberhauser; Gerold Stucki; Jerome Bickenbach; Alarcos Cieza
BackgroundLived health is a person’s level of functioning in his or her current environment and depends both on the person’s environment and biological health. Our study addresses the question whether biological health or lived health is more predictive of self-reported general health (SRGH).MethodsThis is a psychometric study using cross-sectional data from the Spanish Survey on Disability, Independence and Dependency Situation. Data was collected from 17,739 people in the community and 9,707 from an institutionalized population. The following analysis steps were performed: (1) a biological health and a lived health score were calculated for each person by constructing a biological health scale and a lived health scale using Samejima’s Graded Response Model; and (2) variable importance measures were calculated for each study population using Random Forest, with SRGH as the dependent variable and the biological health and the lived health scores as independent variables.ResultsThe levels of biological health were higher for the community-dwelling population than for the institutionalized population. When technical assistance, personal assistance or both were received, the difference in lived health between the community-dwelling population and institutionalized population was smaller. According to Random Forest’s variable importance measures, for both study populations, lived health is a more important predictor of SRGH than biological health.ConclusionsIn general, people base their evaluation of their own health on their lived health experience rather than their experience of biological health. This study also sheds light on the challenges of assessing biological health and lived health at the general population level.
Disability and Rehabilitation | 2010
Alarcos Cieza; Cristina Bostan; Cornelia Oberhauser; Jerome Bickenbach
Purpose. To determine whether changes in health outcomes result from changes in domains of functioning and relevant environmental factors in musculoskeletal conditions. Method. Longitudinal observational study on a convenience sample of 291 patients with low back pain, osteoarthritis, osteoporosis, rheumatoid arthritis and chronic widespread pain. The study was part of the MHADIE project. Data collection was performed at baseline, after 4 and 8 weeks using the ICF Core Sets for the corresponding musculoskeletal conditions. Multilevel models for change were used to determine which ICF categories explain the variability and change over time of the general, physical and mental health according to the SF-36. Results. There are only small fluctuations in the health outcomes. These are related to functions of the locomotor apparatus, such as muscle power, and to activities and participation domains related to them, such as lifting and carrying objects. A large amount of baseline variance is explained with a relatively small number of ICF categories of functioning. Conclusions. This study presents a list of functioning problems and environmental factors relevant to map out both the patterns and the variations in the experience of living with a chronic and painful condition. These are intervention targets common across MSC conditions.
Annals of the Rheumatic Diseases | 2013
U. Kiltz; D. van der Heijde; A. Boonen; Alarcos Cieza; Gerold Stucki; M A Khan; Walter P. Maksymowych; Helena Marzo-Ortega; John D. Reveille; William J. Taylor; Cristina Bostan; J. Braun
Background The burden of ankylosing spondylitis (AS) can be considerable. The patients suffer from pain, stiffness and fatigue, and they are limited in their activities and restricted in social participation. The International Classification of Functioning, Disability and Health (ICF), a model to systematically classify and describe functioning, disability and health in human beings, has been used by the Assessments of SpondyloArthritis international Society (ASAS) as a basis to define a core set of items that are typical and relevant for patients with AS. However, no ICF-based patient-reported outcome measure has been developed for AS patients. Objectives To develop a measure to assess the burden of AS, the AS Health Index, based on the Comprehensive ICF Core Set for AS. Methods Development of this health index is being performed in five phases. I. Preparatory: Development of a pool of items representing the categories of the Comprehensive ICF Core Set, Linkage of various assessment tools for functioning and health to ICF categories II. 1st postal patient survey: Item reduction with Factor Analysis, Rasch Analysis, Spearman rank correlation coefficient III. Expert consultation: Agreement on item reduction with Nominal Consensus Process IV. 2nd postal patient survey: Validation of the draft version and further item reduction, Testing psychometric properties, Rasch Analysis V. Consensus Meeting: Agreement on a final version with Nominal Consensus Process Results The first three phases have been completed. During the preparatory phase (Phase 1): a pool of 251 items in 44 categories was collected from various instruments (identified through literature search) which focus on symptoms and functioning in patients with AS. Phase 2: An international cross sectional study with 1915 AS patients (mean age 51.2±3.6, 53% male, BASDAI 5.5±2.4) was conducted in 4 continents. In 82 items of the functioning part a unidimensional scale, fit to the Rasch model and absence of Differential Item Function could be confirmed. 32 items of the environmental factors part showed a significant correlation between person score and ICF category (correlation coefficient between 0.04 - 0.45). Phase 3: Based on results of the analyses in step 2, an expert committee selected 50 functioning items and 16 environmental factor items using predefined selection criteria (clinimetric properties, ease of wording, coverage of the whole range of ability). Conclusions The item pool has been successfully reduced from 251 down to 66 items. In covering much of the ICF Core Set for AS, these items represent a whole range of abilities of patients with AS. This draft version will be tested in a second survey to create a first version of the ASAS Health Index. The final measure can be used in clinical trials and cohort studies as a new composite index that captures relevant information on the health status of the patients. Disclosure of Interest None Declared