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Prof. Stephan Mühlig 

TU Chemnitz

Klinische Psychologie

Wilhelm-Raabe-Str. 43

09107 Chemnitz  

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Development of a procedure for assessing evidence by means of systematic weighting of patient-relevant endpoints – BEPE

Project leader: Univ.Prof. Dr. Stephan Mühlig, TU Chemnitz


Project aim

Medical and psychotherapeutic therapy guidelines and recommendations can nowadays be increasingly based on impressive empirical evidence. In the ideal case, this is based on the methodologically stringently provided proof of effectiveness and safety of a treatment procedure in the framework of randomised-controlled efficacy studies, the results of which are in turn summarised and weighted in systematic reviews and meta-analyses in order to ultimately substantiate the treatment recommendations. The evaluation of therapy outcomes and the weighting of individual RCT studies (e.g. in systematic Cochrane reviews) have so far taken place almost exclusively using expert-defined (e.g. medical) endpoints or purely methodological quality criteria. The evaluation of usefulness, of expediency or appropriateness of treatment aims by the experts on the one hand and the affected patients on the other is not necessarily congruent, but can rather clearly diverge in the individual case. In the sense of patient participation, an explicit inclusion of patient-relevant endpoints in the evaluation of usefulness of medical interventions and in the weighting of study results should be called for. This requirement seems to be particularly relevant in the area of psychiatric care and will be examined here using the example of bipolar disorders. Aim: Development of an empirically supported weighting procedure for the assessment of medical interventions under systematic inclusion of patient-relevant endpoints. By means of patient/expert survey, a multi-level prioritisation as well as comparative evaluation of the importance of expert-defined and patient-relevant therapy goals in the therapy of bipolar disorders will be undertaken. This evaluation will take place in a sample of bipolar patients (self-help network of the DGBS; bipolar forum) and in a group of clinical experts (DGBS). Main dependent variable: development of weighting factors for patient-based endpoints (symptoms, hospitalisation, quality of life, functional ability) to assess the general evidence under explicit consideration of the patient perspective and gender-specific evaluation aspects.


Work plan

The outlined project will be realised in a multi-phase research design:

  1. Phase 1: Creation of a catalogue of relevant therapy goals and endpoints on the basis of the evaluation of 111 RCTs which were selected for the S3 guideline development "bipolar disorders".
  2. Phase 2: Examination and extension of the catalogue by means of expert survey of n=10 experienced clinicians.
  3. Phase 3: Determination of patient-relevant endpoints (and attribute levels) by means of group discussions and brainstorming procedures with n=25 patients; comparison of the therapy goal prioritisations between experts and patient representatives.
  4. Phase 4: Online survey (Delphi method) of n=300-500 patients from the self-help network and the bipolar forum (http://www.bipolar‐ with the aim of a frequency-based rating of the catalogued endpoints according to personal importance ("hit list" of patient-relevant endpoints according to points system).
  5. Phase 5: Selection of endpoints and operationalisation of the "scenarios" (attribute levels); determination of comparative general preference judgements (aggregated pair comparisons) through a multi-stage conjoint procedure in the form of a group experiment (Discrete Choice Experiment - DCE) and a group discussion (informal group opinion) with n=50 patients in a composition that is as representative as possible (age, gender, morbidity); determination of gender-specific preference judgements.
  6. Phase 6: Finally, from the conjoint analysis, an empirically and statistically founded weighting procedure for therapy offers will be systematically calculated under explicit inclusion of the determined hierarchy of patient-based endpoints; where relevant, derivation of gender-specific weighting factors. The conjoint analysis is based on model with additive composition rule (association rules between outcome measures and levels). To this aim, two sub-goals need to be realised: a) finding out the relevant importance of the outcomes (= what contribution does each outcome measure provide/how important is an outcome measure compared to other outcome measures?) and b) finding out the relevant importance of the outcome levels (=how does the evaluation of the outcome change when a particular level is changed?).


Planned utilisation of results

The results should be published and presented at relevant congresses. We will endeavour to make the determined weighting factors available to the Institute for Quality and Economic Efficiency in the Health System (IQWiG) for future utility analyses. Moreover, the Cochrane Collaboration will be encouraged to more strongly integrate patient-based endpoints into the GRADE system for the differential general evaluation of the evidence situation in the future.


Current status of the project

Phases 1 to 3 of the research design have been concluded (status: end of May 2012); currently, the BEPE project is in phase 4.


A systematic literature review (relevant textbooks, randomised-controlled studies, guidelines etc.) in terms of relevant therapy aims in the treatment of bipolar disorders was followed by an extension of the composition by expert-defined treatment goals (expert group).


The general catalogue was presented to and put up for discussion by bipolar patients (N=95) on 3rd February 2012 for the "bipolar self-help day" in the Vivantes Humboldt Clinic for Psychiatry, Psychotherapy and Psychosomatics in Berlin (leader: Prof. Dr. med. Peter Bräunig). Within qualitative focus groups, patients were asked to discuss the goals mentioned in the catalogue and to add or modify lacking therapy goals or goals that were not formulated in a patient-based manner.


The outcome of the focus groups (item pool) forms the basis for the paper-and-pencil and online survey of bipolar patients and clinical experts in the treatment of bipolar disorders. In the construction of the questionnaire, n=10 bipolar patients and n=3 clinical experts gave hints and feedback regarding the formulation and arrangement of questions in a feedback system.


Next steps in the project

The final version of the questionnaire will be sent from June 2012 to patients and clinical treatment providers through various cooperation partners (DGBS, bipolaris, Humbolt-Klinikum Berlin). Subsequently, the answers will be evaluated through factor analysis in order to filter out and contrast (patients vs. experts) the most important dimensions in the treatment of bipolar disorders. The patient-related dimensions form the basis for the creation of the "Discrete Choice Experiment" to examine the relative importance of treatment goals (phase 5).


Project homepage:




Cooperation partners:

< DIANA - Brenner   |  SITD - Scherer >