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Featured researches published by Felix Fischer.


BMC Complementary and Alternative Medicine | 2014

High prevalence but limited evidence in complementary and alternative medicine: guidelines for future research

Felix Fischer; George Lewith; Claudia M. Witt; Klaus Linde; Klaus von Ammon; Francesco Cardini; Torkel Falkenberg; Vinjar Fønnebø; Helle Johannessen; Bettina Reiter; Bernhard Uehleke; Wolfgang Weidenhammer; Benno Brinkhaus

The use of complementary and alternative Medicine (CAM) has increased over the past two decades in Europe. Nonetheless, research investigating the evidence to support its use remains limited. The CAMbrella project funded by the European Commission aimed to develop a strategic research agenda starting by systematically evaluating the state of CAM in the EU. CAMbrella involved 9 work packages covering issues such as the definition of CAM; its legal status, provision and use in the EU; and a synthesis of international research perspectives. Based on the work package reports, we developed a strategic and methodologically robust research roadmap based on expert workshops, a systematic Delphi-based process and a final consensus conference. The CAMbrella project suggests six core areas for research to examine the potential contribution of CAM to the health care challenges faced by the EU. These areas include evaluating the prevalence of CAM use in Europe; the EU cititzens’ needs and attitudes regarding CAM; the safety of CAM; the comparative effectiveness of CAM; the effects of meaning and context on CAM outcomes; and different models for integrating CAM into existing health care systems. CAM research should use methods generally accepted in the evaluation of health services, including comparative effectiveness studies and mixed-methods designs. A research strategy is urgently needed, ideally led by a European CAM coordinating research office dedicated to fostering systematic communication between EU governments, the public, charitable and industry funders, researchers and other stakeholders. A European Centre for CAM should also be established to monitor and further a coordinated research strategy with sufficient funds to commission and promote high quality, independent research focusing on the public’s health needs and pan-European collaboration. There is a disparity between highly prevalent use of CAM in Europe and solid knowledge about it. A strategic approach on CAM research should be established to investigate the identified gaps of knowledge and to address upcoming health care challenges.


Journal of Affective Disorders | 2015

Validation of patient health questionnaire (PHQ) for major depression in Chinese outpatients with multiple somatic symptoms: A multicenter cross-sectional study

Nana Xiong; Kurt Fritzsche; Jing Wei; Xia Hong; Rainer Leonhart; Xudong Zhao; Lan Zhang; Liming Zhu; Guoqing Tian; Sandra Nolte; Felix Fischer

BACKGROUND Despite the high co-morbidity of depressive symptoms in patients with multiple somatic symptoms, the validity of the 9-item Patient Health Questionnaire (PHQ-9) has not yet been investigated in Chinese patients with multiple somatic symptoms. METHODS The multicenter cross-sectional study was conducted in ten outpatient departments located in four cities in China. The psychometric properties of the PHQ-9 were examined by confirmative factor analysis (CFA). Criterion validation was undertaken by comparing results with depression diagnoses obtained from the Mini International Neuropsychiatric Interview (MINI) as the gold standard. RESULTS Overall, 491 patients were recruited of whom 237 had multiple somatic symptoms (SOM+ group, PHQ-15≥10). Cronbach׳s α of the PHQ-9 was 0.87, 0.87, and 0.90 for SOM+ patients, SOM- patients, and total sample respectively. All items and the total score were moderately correlated. The factor models of PHQ-9 tested by CFA yielded similar diagnostic performance when compared to sum score estimation. Multi-group confirmatory factor analysis based on unidimensional model showed similar psychometric properties over the groups with low and high somatic symptom burden. The optimal cut-off point to detect depression in Chinese outpatients was 10 for PHQ-9 (sensitivity=0.77, specificity=0.76) and 3 for PHQ-2 (sensitivity=0.77, specificity=0.74). LIMITATIONS Potential selection bias and nonresponse bias with applied sampling method. CONCLUSIONS PHQ-9 (cut-off point=10) and PHQ-2 (cut-off point=3) were reliable and valid to detect major depression in Chinese patients with multiple somatic symptoms.


Forschende Komplementarmedizin | 2014

A Research Roadmap for Complementary and Alternative Medicine - What We Need to Know by 2020

Felix Fischer; George Lewith; Claudia M. Witt; Francesco Cardini; Helle Johannessen; Bernhard Uehleke

BACKGROUND The CAMbrella coordination action was funded within the Framework Programme 7. Its aim is to provide a research roadmap for clinical and epidemiological research for complementary and alternative medicine (CAM) that is appropriate for the health needs of European citizens and acceptable to their national research institutes and healthcare providers in both public and private sectors. One major issue in the European research agenda is the demographic change and its impact on health care. Our vision for 2020 is that there is an evidence base that enables European citizens to make informed decisions about CAM, both positive and negative. This roadmap proposes a strategic research agenda for the field of CAM designed to address future European health care challenges. This roadmap is based on the results of CAMbrella’s several work packages, literature reviews and expert discussions including a consensus meeting. METHODS We first conducted a systematic literature review on key issues in clinical and epidemiological research in CAM to identify the general concepts, methods and the strengths and weaknesses of current CAM research. These findings were discussed in a workshop (Castellaro, Italy, September 7–9th 2011) with international CAM experts and strategic and methodological recommendations were defined in order to improve the rigor and relevance of CAM research. These recommendations provide the basis for the research roadmap, which was subsequently discussed in a consensus conference (Järna, Sweden, May 9–11th 2012) with all CAMbrella members and the CAMbrella advisory board. The roadmap was revised after this discussion in CAMbrella Work Package (WP) 7 and finally approved by CAMbrella’s scientific steering committee on September 26th 2012. RESULTS Our main findings show that CAM is very heterogenous in terms of definitions and legal regulations between the European countries. In addition, citizens’ needs and attitudes towards CAM as well as the use and provision of CAM differ significantly between countries. In terms of research methodology, there was consensus that CAM researchers should make use of all the commonly accepted scientific research methods and employ those with utmost diligence combined in a mixed methods framework. CONCLUSIONS We propose 6 core areas of research that should be investigated to achieve a robust knowledge base and to allow stakeholders to make informed decisions. These are: Research into the prevalence of CAM in Europe: Reviews show that we do not know enough about the circumstances in which CAM is used by Europeans. To enable a common European strategic approach, a clear picture of current use is of the utmost importance. Research into differences regarding citizens’ attitudes and needs towards CAM: Citizens are the driver for CAM utilization. Their needs and views on CAM are a key priority, and their interests must be investigated and addressed in future CAM research. Research into safety of CAM: Safety is a key issue for European citizens. CAM is considered safe, but reliable data is scarce although urgently needed in order to assess the risk and cost-benefit ratio of CAM. Research into the comparative effectiveness of CAM: Everybody needs to know in what situation CAM is a reasonable choice. Therefore, we recommend a clear emphasis on concurrent evaluation of the overall effectiveness of CAM as an additional or alternative treatment strategy in real-world settings. Research into effects of context and meaning: The impact of effects of context and meaning on the outcome of CAM treatments must be investigated; it is likely that they are significant. Research into different models of CAM health care integration: There are different models of CAM being integrated into conventional medicine throughout Europe, each with their respective strengths and limitations. These models should be described and concurrently evaluated; innovative models of CAM provision in health care systems should be one focus for CAM research. We also propose a methodological framework for CAM research. We consider that a framework of mixed methodological approaches is likely to yield the most useful information. In this model, all available research strategies including comparative effectiveness research utilising quantitative and qualitative methods should be considered to enable us to secure the greatest density of knowledge possible. Stakeholders, such as citizens, patients and providers, should be involved in every stage of developing the specific and relevant research questions, study design and the assurance of real-world relevance for the research. Furthermore, structural and sufficient financial support for research into CAM is needed to strengthen CAM research capacity if we wish to understand why it remains so popular within the EU. In order to consider employing CAM as part of the solution to the health care, health creation and self-care challenges we face by 2020, it is vital to obtain a robust picture of CAM use and reliable information about its cost, safety and effectiveness in real-world settings. We need to consider the availability, accessibility and affordability of CAM. We need to engage in research excellence and utilise comparative effectiveness approaches and mixed methods to obtain this data. Our recommendations are both strategic and methodological. They are presented for the consideration of researchers and funders while being designed to answer the important and implicit questions posed by EU citizens currently using CAM in apparently increasing numbers. We propose that the EU actively supports an EU-wide strategic approach that facilitates the development of CAM research. This could be achieved in the first instance through funding a European CAM coordinating research office dedicated to foster systematic communication between EU governments, public, charitable and industry funders as well as researchers, citizens and other stakeholders. The aim of this office would be to coordinate research strategy developments and research funding opportunities, as well as to document and disseminate international research activities in this field. With the aim to develop sustainability as second step, a European Centre for CAM should be established that takes over the monitoring and further development of a coordinated research strategy for CAM, as well as it should have funds that can be awarded to foster high quality and robust independent research with a focus on citizens health needs and pan-European collaboration. We wish to establish a solid funding for CAM research to adequately inform health care and health creation decision-making throughout the EU. This centre would ensure that our vision of a common, strategic and scientifically rigorous approach to CAM research becomes our legacy and Europe’s reality. We are confident that our recommendations will serve these essential goals for EU citizens.


Psychosomatic Medicine | 2012

Computerized adaptive testing--ready for ambulatory monitoring

Matthias Rose; Jakob B. Bjorner; Felix Fischer; Milena D. Anatchkova; Barbara Gandek; Burghard F. Klapp; John E. Ware

Background Computerized adaptive tests (CATs) have abundant theoretical advantages over established static instruments, which could improve ambulatory monitoring of patient-reported outcomes (PROs). However, an empirical demonstration of their practical benefits is warranted. Methods We reviewed the literature and evaluated existing data to discuss the potential of CATs for use in ambulatory monitoring outside clinical facilities. Results Computerized adaptive tests are not being used for ambulatory monitoring, but initial results from their use in health care research allow for discussion of some issues relevant to ambulatory care. Evidence shows that CATs can capture the most relevant health outcomes as well as established static tools, with substantially decreased respondent burden. They can be more precise than static tools of similar length and can reduce floor and ceiling effects. Computerized adaptive tests can reliably measure a construct over time with different items, which yields the potential of introducing item exposure control in ambulatory monitoring. Studies have shown that CATs can be at least as valid as well-designed static tools in group comparisons, but further investigation is needed to determine whether psychometric advantages lead to increased responsiveness of CATs. Conclusions Ambulatory monitoring of PROs demands short, yet very precise measurements, which can be repeated up to many times a day. Computerized adaptive tests may address several present shortcomings in ambulatory monitoring of PROs efficiently. However, most CAT developments have primarily focused on psychometric improvements. To use the full potential of CATs for ambulatory monitoring purposes, content must also be carefully considered. Abbreviations A-CAT = anxiety CAT ADL = activities of daily living CAT = computerized adaptive test D-CAT = depression CAT GAD-7 = Generalized Anxiety Disorder scale ICD-10 = International Classification of Diseases 10th Edition IRT = item response theory ISR = ICD-10 Symptom Rating PDA = personal digital assistant PHQ-9 = Patient Health Questionnaire – Depression scale PRO = patient-reported outcome PROMIS = Patient-Reported Outcomes Measurement Information System SF-36 = 36-Item Short Form Health Survey


Journal of Clinical Epidemiology | 2016

Using Patient Health Questionnaire-9 item parameters of a common metric resulted in similar depression scores compared to independent item response theory model reestimation

Gregor Liegl; Inka Wahl; Anne Berghöfer; Sandra Nolte; Christoph Pieh; Matthias Rose; Felix Fischer

OBJECTIVES To investigate the validity of a common depression metric in independent samples. STUDY DESIGN AND SETTING We applied a common metrics approach based on item-response theory for measuring depression to four German-speaking samples that completed the Patient Health Questionnaire (PHQ-9). We compared the PHQ item parameters reported for this common metric to reestimated item parameters that derived from fitting a generalized partial credit model solely to the PHQ-9 items. We calibrated the new model on the same scale as the common metric using two approaches (estimation with shifted prior and Stocking-Lord linking). By fitting a mixed-effects model and using Bland-Altman plots, we investigated the agreement between latent depression scores resulting from the different estimation models. RESULTS We found different item parameters across samples and estimation methods. Although differences in latent depression scores between different estimation methods were statistically significant, these were clinically irrelevant. CONCLUSION Our findings provide evidence that it is possible to estimate latent depression scores by using the item parameters from a common metric instead of reestimating and linking a model. The use of common metric parameters is simple, for example, using a Web application (http://www.common-metrics.org) and offers a long-term perspective to improve the comparability of patient-reported outcome measures.


Nordic Journal of Psychiatry | 2015

Effect of time and duration of untreated psychosis on cognitive and social functioning in Chinese patients with first-episode schizophrenia: A 1-year study

Anisha Heeramun-Aubeeluck; Na Liu; Felix Fischer; Nan Huang; Fazhan Chen; Leiying He; Chengqing Yang; Yanli Luo; Zheng Lu

Abstract Background: Duration of untreated psychosis (DUP) is believed to exert a deleterious effect on cognitive and social function. However, to date, results remain inconclusive. Aims: To investigate the effect of time and DUP on cognitive and social functioning in first-episode schizophrenia (FES) subjects in Shanghai, China. Methods: FES patients were subjected to a comprehensive neuropsychological battery, the Personal and Social Performance scale (PSP) and the Positive and Negative Symptoms Scale (PANSS) at baseline, 6 month and 1 year. DUP was defined as the time from onset of first psychotic symptoms to first contact made with psychiatric services. Results: Though the rate of non-completers in our observational study was relatively high (40%), we did not find any significant differences between the completers and non-completers (P-values > 0.05). Significant impairments in verbal learning and memory and executive function were noted over the course of 1 year. Meanwhile, social function improved significantly over the course of 1 year. Although, DUP did not share any significant relationship with cognitive or social function the effect estimate (range: − 0.03 to 0.02) of an increase of 1 month in DUP was clinically non-negligible in this study. Conclusions: In Chinese FES patients, the longitudinal course of cognitive function tends to worsen in verbal learning and memory, executive function and motor speed, while that of social function tends to improve. DUP was not found to be associated with cognitive or social deterioration in Chinese FES.


Quality of Life Research | 2015

A new computerized adaptive test advancing the measurement of health-related quality of life (HRQoL) in children: the Kids-CAT

Janine Devine; Christiane Otto; Matthias Rose; Dana Barthel; Felix Fischer; Holger Mühlan; Sandra Nolte; Silke Schmidt; V. Ottova-Jordan; Ulrike Ravens-Sieberer

Purpose Assessing health-related quality of life (HRQoL) via Computerized Adaptive Tests (CAT) provides greater measurement precision coupled with a lower test burden compared to conventional tests. Currently, there are no European pediatric HRQoL CATs available. This manuscript aims at describing the development of a HRQoL CAT for children and adolescents: the Kids-CAT, which was developed based on the established KIDSCREEN-27 HRQoL domain structure.


Quality of Life Research | 2018

Measurement invariance and general population reference values of the PROMIS Profile 29 in the UK, France, and Germany

Felix Fischer; Chris Gibbons; Joël Coste; Jose M. Valderas; Matthias Rose; Alain Leplège

PurposeComparability of patient-reported outcome measures over different languages is essential to allow cross-national research. We investigate the comparability of the PROMIS Profile 29, a generic health-related quality of life measure, in general population samples in the UK, France, and Germany and present general population reference values.MethodsA web-based survey was simultaneously conducted in the UK (n = 1509), France (1501), and Germany (1502). Along with the PROMIS Profile 29, we collected sociodemographic information as well as the EQ-5D. We tested measurement invariance by means of multigroup confirmatory factor analysis (CFA). Differences in the health-related quality of life between countries were modeled by linear regression analysis. We present general population reference data for the included PROMIS domains utilizing plausible value imputation and quantile regression.ResultsMultigroup CFA of the PROMIS Profile 29 showed that factor means are insensitive to potential measurement bias except in one item. We observed significant differences in patient-reported health between countries, which could be partially explained by the differences in overall ratings of health. The physical function and pain interference scales showed considerable floor effects in the normal population in all countries.ConclusionsScores derived from the PROMIS Profile 29 are largely comparable across the UK, France, and Germany. Due to the use of plausible value imputation, the presented general population reference values can be compared to data collected with other PROMIS short forms or computer-adaptive tests.


PLOS ONE | 2014

Pregnancy in Multiple Sclerosis: A Questionnaire Study

Nadja Borisow; Friedemann Paul; Stephanie Ohlraun; Daniel Pach; Felix Fischer; Jan Dörr

Background Multiple sclerosis (MS) preferentially affects females at childbearing age. For this reason patients and treating physicians were frequently confronted with questions concerning family planning, pregnancy and birth. Objective The aim of this study was to evaluate the expertise about pregnancy related topics in multiple sclerosis of neurologists in private practice. Methods We developed a survey with 16 multiple choice questions about pregnancy related topics and sent it to neurologists in private practice in Berlin, Germany. Results 56 completed questionnaires were sent back. 54% of all questions were answered correctly, 21% of the questions were answered with “I don’t know”. Correct answers were more often given by physicians who treat more than 400 MS patients per year (p = 0.001). Further positive associations were found for assumed relevance of the topic (p = 0.002) and the degree of counseling (p<0.001). Conclusion To provide a comprehensive counseling, MS patients with desire for children should be counseled by physicians with a lot of experience in MS treatment.


International Journal of Integrated Care | 2016

Evaluation of Quality Indicators of Integrated Care in a Regional Psychiatry Budget – A Pre-Post Comparison by Secondary Data Analysis

Anne Berghöfer; Svenja Hubmann; Thomas Birker; Torsten Hejnal; Felix Fischer

The Regional Psychiatry Budget (RPB), as a special arrangement within the German Federal Hospital Refund Regulation, is based on the capitation principle. A lump sum is allocated to a major inpatient care provider in a large region on a yearly basis. Under this model, the provider is free to offer all forms of treatment and to construct individual models of integrated care that specifically suit the region and the needs of community members. The present study aimed to evaluate selected aspects that represent a change in the psychiatric health status of patients in the covered region under the conditions of the RPB. We performed a secondary data analysis of administrative data of 19,913 cases generated by the hospital in a pre-post comparison of the periods before and under RPB conditions. The average length of an inpatient stay was reduced by approximately 22 % and could be partially replaced by day care. Selected indicators suggest equal or higher quality of care with stable cost in the population in need of psychiatric care in the district.

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Gregor Liegl

Humboldt University of Berlin

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Inka Wahl

University of Hamburg

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Kurt Fritzsche

University Medical Center Freiburg

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