Felix H Fischer

Charité Universitätsmedizin Berlin | Charité · Medical Department, Division of Psychosomatic Medicine

Background Recently, a growing number of Item-Response Theory (IRT) models has been published, which allow estimation of a common latent variable from data derived by different Patient Reported Outcomes (PROs). When using data from different PROs, direct estimation of the latent variable has some advantages over the use of sum score conversion tabl...

To investigate differential item functioning (DIF) of PROMIS Depression items between US and German samples we compared data from the US PROMIS calibration sample (n = 780), a German general population survey (n = 2,500) and a German clinical sample (n = 621). DIF was assessed in an ordinal logistic regression framework, with 0.02 as criterion for...

Background Numerous drugs used in the treatment of psychiatric disorders are substrates of cytochrome P450 enzymes and are potential candidates for drug-drug interactions (DDIs). Methods Claims data of a German statutory health insurance company from severely mentally ill patients who registered in an integrated care contract from August 2004 to De...

Background: The interpretation of patient-reported outcomes requires appropriate comparison data. Currently, no patient-specific reference data exist for the Patient-Reported Outcome Measurement Information System (PROMIS) Physical Function (PF), Upper Extremity (UE), and Pain Interference (PI) scales for individuals 50 years and older. Questions...

Purpose To calibrate the item parameters of the German PROMIS® Pain interference (PROMIS PI) items using an item-response theory (IRT) model and investigate psychometric properties of the item bank. Methods Forty items of the PROMIS PI item bank were collected in a convenience sample of 660 patients, which were recruited during inpatient rheumatol...

Background Cut-offs on self-report depression screening tools are designed to identify many more people than those who meet criteria for major depressive disorder. In a recent analysis of the European Health Interview Survey (EHIS), the percentage of participants with Patient Health Questionnaire-8 (PHQ-8) scores ≥10 was reported as major depressio...

Objectives: To develop item response theory (IRT) models for the Oxford Hip and Knee Scores (OHS/OKS) which convert patient responses into continuous scores with quantifiable precision, and provide these as web applications for efficient score conversion. Study design and setting: Data from the NHS PROMs programme were used to test the assumptio...

Objective: To investigate whether a multi-item performance outcome (PerfO) measure, the physical performance test (PPT), can be calibrated to a common scale with patient-reported outcome (PRO) measures, using the PROMIS physical function (PF) metric. Study design and setting: We analyzed baseline data (N=1,113) from an international trial in end...

Background There are concerns that the measurement of depression by the Patient Health Questionnaire-9 (PHQ-9), a self-report screening questionnaire, is biased by comorbid stroke sequelae. We, therefore, aimed to investigate these concerns in stroke, benchmarked against a non-stroke comparison sample, using factor analysis. Methods The secondary...

Background: In the past, the IIEF‑5 (International Index of Erectile Function 5 ) was predominantly used to measure erectile function in prostate cancer patients. Following international developments, the domain "sexuality" of the EPIC-26 (Expanded Prostate Cancer Index Composite 26) is increasingly used in Germany. Objective: The aim of this wo...

Objectives: To apply item response theory as a framework for studying measurement error in superiority trials which use patient-reported outcome measures (PROMs). Study design and setting: We reanalyzed data from the TOPKAT trial, which compared the Oxford Knee Score (OKS) responses of patients undergoing partial or total knee replacement, using...

The seven-item Hospital Anxiety and Depression Scale Depression subscale (HADS-D) and the total score of the 14-item HADS (HADS-T) are both used for major depression screening. Compared to the HADS-D, the HADS-T includes anxiety items and requires more time to complete. We compared the screening accuracy of the HADS-D and HADS-T for major depressio...

Purpose The assessment of health-related quality of life (HRQOL) measured via patient-reported outcomes (PROs) is a key component in clinical trials and increasingly used in clinical routine worldwide. Two PRO measures (PROMs) that share the same definition of health and report outcomes on a comparable T-metric anchored to general population sample...

Background and Objectives The EORTC Quality of Life Utility Core 10 Dimensions (QLU-C10D) and the Patient-Reported Outcome Measurement Information System Preference Score (PROPr) are new health state utility (HSU) scores for quality-adjusted life years in cost-effectiveness analyses. Both are expected to measure HSU more comprehensively than existi...

The International Classification of Diseases (ICD-11) features a new classification of personality disorders (PD), focusing on the severity of PD. Although there are numerous self-report measures that assess PD severity, to date only the Personality Disorder Severity-ICD-11 (PDS-ICD-11) is based on ICD-11's operationalization of PD. Initial results...

Objective: Researchers and clinicians assessing the health status of patients treated in rehabilitation facilities use different outcome measures. Translating scores from one measure into another would be useful for both clinical and research purposes. The aim of the Reha Toolbox study was to link three key rehabilitation measures including the Wor...

Aims: Physical function (PF) is an important outcome in many medical fields, including nephrology. The most frequently used assessment types for measuring PF are patient-reported outcome (PRO) and performance outcome (PerfO) measures. While single-item PerfO measures have been shown to correlate poorly with PRO measures, recent studies found high c...

Purpose: Patient-Reported Outcomes (PROs) and its measures (PROMs) are key to outcome assessment in Fibromyalgia (FM) trials. The aim of this review was to investigate which domains and instruments were assessed in recent FM trials and to compare them to recommendations by the Outcome Measures in Rheumatology (OMERACT) initiative. In addition, we i...

Early career researchers (ECRs) are important stakeholders leading efforts to catalyze systemic change in research culture and practice. Here, we summarize the outputs from a virtual unconventional conference (unconference), which brought together 54 invited experts from 20 countries with extensive experience in ECR initiatives designed to improve...

Hintergrund: Patient-Reported Outcomes (PROs; z.B. Schmerz, Körperliche Funktionsfähigkeit) stellen einen Kernaspekt der Diagnosefindung und Erfolgsmessung in klinischen Studien bei Fibromyalgie-Patient*innen dar. Die Outcome Measures in Rheumatology (OMERACT) Initiative hat Empfehlungen zur Erfassung des Therapieerfolgs bei Fibromyalgie herausgege...

The ICD-11 features a new classification of personality disorders (PD), focusing on the severity of PD. Although there are numerous self-report measures that assess PD severity, to date only the Personality Disorder Severity ICD-11 (PDS-ICD-11) is based on ICD-11’s operationalization of PD. Initial results indicated that the PDS-ICD-11 measures a u...

Background The PROMIS Preference score (PROPr) is a new generic preference-based health-related quality of life (HRQoL) score that can be used as a health state utility (HSU) score for quality-adjusted life years (QALYs) in cost-utility analyses (CUAs). It is the first HSU score based on item response theory (IRT) and has demonstrated favorable psy...

Purpose To deliver patient-reported outcome (PRO) reference data for breast cancer and various other breast diseases to facilitate the interpretation of PRO scores during routine breast cancer treatment. Methods To determine reference baseline values for the PRO measures EORTC QLQ-C30 and EORTC QLQ-BR23, PRO data captured in the breast cancer cent...

Thermometers and baumanometers frequently contain mercury, a toxic heavy metal. Inadequate management of this substance can constitute an occupational hazard by exposing health care professionals to health risks including memory loss, psychosomatic symptoms, fatigue, and other signs of cognitive dysfunction as reported in several studies. Purpose:...

Zusammenfassung Auskünfte von Patient*innen über die eigene Lebensqualität, Erfahrungen in der Versorgung sowie individuelle Einschätzungen zu Therapieverläufen und -ergebnissen gewinnen zunehmend an Bedeutung. Patient*innenberichtete Merkmale können sich auf subjektive Informationen zur eigenen Gesundheit (Patient-reported Outcome Measures [PROMs]...

Purpose In developing item banks for patient reported outcomes (PROs), nonparametric techniques are often used for investigating empirical item response curves, whereas final banks usually use parsimonious parametric models. A flexible approach based on monotonic polynomials (MP) provides a compromise by modeling items with both complex and simpler...

Multiple neurobiological pathways have been implicated in the pathobiology of major depressive disorder (MDD). The identification of reliable biological substrates across the entire MDD spectrum, however, is hampered by a vast heterogeneity in the clinical presentation, presumably as a consequence of heterogeneous pathobiology. One way to overcome...

Objectives The Patient-Reported Outcome Measurement Information System (PROMIS) Preference score (PROPr) can be used to assess health state utility (HSU) and estimate quality-adjusted life-years in cost-effectiveness analyses. It is based on item response theory and promises to overcome limitations of existing HSU scores such as ceiling effects. Th...

Shortened versions of self-reported questionnaires may be used to reduce respondent burden. When shortened screening tools are used, it is desirable to maintain equivalent diagnostic accuracy to full-length forms. This manuscript presents a case study that illustrates how external data and individual participant data meta-analysis can be used to as...

Thirty-five new items were introduced to the Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Functioning item bank to extend the range of measurement. Differential item functioning (DIF) can introduce biases to inter-country comparisons, potentially leading to systematically different physical function scores. Individuals...

Background Despite the progress of research and treatment for breast cancer, still up to 30% of the patients afflicted will develop distant disease. Elongation of survival and maintaining the quality of life (QoL) become pivotal issues guiding the treatment decisions. One possible approach to optimise survival and QoL is the use of patient-reported...

Early career researchers (ECRs) are important stakeholders leading efforts to catalyze systemic change in the conduct and communication of science. Here, we summarize the outputs from a virtual unconventional conference (unconference), which brought together 54 invited experts from 20 countries with extensive experience in ECR initiatives designed...

Background: The PROMIS Preference score (PROPr) is a new generic preference-based health-related quality of life (HRQoL) score that can be used as a health state utility (HSU) score for quality-adjusted life years (QALYs) in cost-utility analyses (CUAs). It is the first HSU score based on item response theory (IRT) and has favorable psychometric pr...

Objectives: Positive predictive values (PPVs) and negative predictive values (NPVs) are frequently reported to put estimates of accuracy of a diagnostic test in clinical context and to obtain risk estimates for a given patient taking into account baseline prevalence in the population. In order to calculate PPV and NPV, tests with ordinally or cont...

Background: Stress is a major risk factor for the impairment of psychological well-being. The present study aimed to evaluate the empirical evidence of the Transactional Stress Model proposed by Lazarus and Folkman in patients with psychosomatic health conditions. Methods: A structural equation model was applied in two separate subsamples of inp...

Background Previous research on the depression scale of the Patient Health Questionnaire (PHQ-9) has found that different latent factor models have maximized empirical measures of goodness-of-fit. The clinical relevance of these differences is unclear. We aimed to investigate whether depression screening accuracy may be improved by employing latent...

Background EQ-5D health state utilities (HSU) are commonly used in health economics to compute quality-adjusted life years (QALYs). The EQ-5D, which is country-specific, can be derived directly or by mapping from self-reported health-related quality of life (HRQoL) scales such as the PROMIS-29 profile. The PROMIS-29 from the Patient Reported Outcom...

Objective: The PROMIS® physical function (PF) item bank has been developed to standardize patient-reported PF across medical fields. However, evidence of scoring equivalence across cardiology and rheumatology patients is still missing. Therefore, this study aims to investigate both 1) the extent of disease-related differential item functioning (DI...

Objectives Validated diagnostic interviews are required to classify depression status and estimate prevalence of disorder, but screening tools are often used instead. We used individual participant data meta-analysis to compare prevalence based on standard Hospital Anxiety and Depression Scale – depression subscale (HADS-D) cutoffs of ≥8 and ≥11 v...

Recent developments in the dimensional assessment of personality functioning have made the implementation of latent measurement models increasingly attractive. In this study, we applied item response theory (IRT) to a well-established personality functioning instrument (the OPD Structure Questionnaire) to identify a unidimensional latent trait and...

Background: EQ-5D health utility (HU) scores are commonly used in health economics to compute quality-adjusted life years (QALYs). EQ-5D scores, which are country-specific, can be derived directly or by mapping from self-reported health-related quality of life (HRQoL) scales such as the PROMIS-29 profile. The PROMIS-29 from the Patient Reported Out...

Background: EQ-5D health state utilities (HSU) are commonly used in health economics to compute quality-adjusted life years (QALYs). The EQ-5D, which is country-specific, can be derived directly or by mapping from self-reported health-related quality of life (HRQoL) scales such as the PROMIS-29 profile. The PROMIS-29 from the Patient Reported Outco...

Background: EQ-5D health state utilities (HSU) are commonly used in health economics to compute quality-adjusted life years (QALYs). The EQ-5D, which is country-specific, can be derived directly or by mapping from self-reported health-related quality of life (HRQoL) scales such as the PROMIS-29 profile. The PROMIS-29 from the Patient Reported Outco...

Importance The Patient Health Questionnaire depression module (PHQ-9) is a 9-item self-administered instrument used for detecting depression and assessing severity of depression. The Patient Health Questionnaire–2 (PHQ-2) consists of the first 2 items of the PHQ-9 (which assess the frequency of depressed mood and anhedonia) and can be used as a fir...

Importance: The Patient Health Questionnaire depression module (PHQ-9) is a 9-item self-administered instrument used for detecting depression and assessing severity of depression. The Patient Health Questionnaire–2 (PHQ-2) consists of the first 2 items of the PHQ-9 (which assess the frequency of depressed mood and anhedonia) and can be used as a fi...

Purpose: The number of non-responders to treatment among patients with chronic pain (CP) is high, although intensive multimodal treatment is broadly accessible. One reason is the large variability in manifestations of CP. To facilitate the development of tailored treatment approaches, phenotypes of CP must be identified. In this study, we aim to i...

Introduction: Dimensional models of personality disorders (PD) in the DSM-5 and ICD-11 share a focus on impairments in self and interpersonal functioning to represent the general features and severity of PD. This new perspective has led to the development of numerous measures for assessing individual differences in PD severity. While this improves...

Objective: Depression symptom questionnaires are not for diagnostic classification. Patient Health Questionnaire-9 (PHQ-9) scores ≥ 10 are nonetheless often used to estimate depression prevalence. We compared PHQ-9 ≥ 10 prevalence to Structured Clinical Interview for DSM (SCID) major depression prevalence and assessed whether an alternative PHQ-9...

Researchers increasingly use meta-analysis to synthesize the results of several studies in order to estimate a common effect. When the outcome variable is continuous, standard meta-analytic approaches assume that the primary studies report the sample mean and standard deviation of the outcome. However, when the outcome is skewed, authors sometimes...

Introduction: To achieve optimized blood glucose concentrations (assessed by HbA1c) and high health-related quality of life (HRQL), children and adolescents with diabetes mellitus type 1 (T1DM) must follow strict disease management strategies. This study aims to investigate HRQL of children and adolescents with T1DM and its association with HbA1c v...

Objective: Two previous individual participant data meta-analyses (IPDMAs) found that different diagnostic interviews classify different proportions of people as having major depression overall or by symptom levels. We compared the odds of major depression classification across diagnostic interviews among studies that administered the Depression s...

Background: Screening for major depression with the Patient Health Questionnaire-9 (PHQ-9) can be done using a cutoff or the PHQ-9 diagnostic algorithm. Many primary studies publish results for only one approach, and previous meta-analyses of the algorithm approach included only a subset of primary studies that collected data and could have publish...

Equivalency of the diagnostic accuracy of the PHQ-8 and PHQ-9: a systematic review and individual participant data meta-analysis – ERRATUM - Yin Wu, Brooke Levis, Kira E. Riehm, Nazanin Saadat, Alexander W. Levis, Marleine Azar, Danielle B. Rice, Jill Boruff, Pim Cuijpers, Simon Gilbody, John P.A. Ioannidis, Lorie A. Kloda, Dean McMillan, Scott B....

Background: Communication between health care provider and patients in oncology presents challenges. Communication skills training have been frequently developed to address those. Given the complexity of communication training, the choice of outcomes and outcome measures to assess its effectiveness is important. The aim of this paper is to 1) perf...

Background: Screening for major depression with the Patient Health Questionnaire-9 (PHQ-9) can be done using a cutoff or the PHQ-9 diagnostic algorithm. Many primary studies publish results for only one approach, and previous meta-analyses of the algorithm approach included only a subset of primary studies that collected data and could have publis...

Background Item 9 of the Patient Health Questionnaire-9 (PHQ-9) queries about thoughts of death and self-harm, but not suicidality. Although it is sometimes used to assess suicide risk, most positive responses are not associated with suicidality. The PHQ-8, which omits Item 9, is thus increasingly used in research. We assessed equivalency of total...

Purpose Fatigue is one of the most disabling symptoms in cancer patients. Many instruments exist to measure fatigue. This variety impedes the comparison of data across studies or to the general population. We aimed to estimate a common metric based on six different fatigue instruments (EORTC QLQ-C30 subscale fatigue, EORTC QLQ-FA12, MFI subscale Ge...

Objective: Some nursing homes for the elderly in Germany integrate complex complementary and integrative medicine interventions in the form of hydrotherapy, herbal and mind-body therapies, physical activities, and healthy eating, known as Kneipp therapy (KT), in care. This pilot study explored health- and work-related characteristics and acceptanc...

The need for replication of initial results has been rediscovered only recently in many fields of research. In preclinical biomedical research, it is common practice to conduct exact replications with the same sample sizes as those used in the initial experiments. Such replication attempts, however, have lower probability of replication than is gen...

Background Many cancer patients are interested in complementary and integrative medicine during and after regular cancer treatment. Given the high number of users it is important that physicians and patients engage in a dialog about useful complementary and integrative medicine therapies during cancer treatment. In a prospective, multi-center, clus...