Planning performance in schizophrenia patients: a meta-analysis of the influence of task difficulty and clinical and sociodemographic variables.

BACKGROUND: Despite a large body of research on planning performance in adult schizophrenia patients, results of individual studies are equivocal, suggesting either no, moderate or severe planning deficits. This meta-analysis therefore aimed to quantify planning deficits in schizophrenia and to examine potential sources of the heterogeneity seen in the literature. METHOD: The meta-analysis comprised outcomes of planning accuracy of 1377 schizophrenia patients and 1477 healthy controls from 31 different studies which assessed planning performance using tower tasks such as the Tower of London, the Tower of Hanoi and the Stockings of Cambridge. A meta-regression analysis was applied to assess the influence of potential moderator variables (i.e. sociodemographic and clinical variables as well as task difficulty). RESULTS: The findings indeed demonstrated a planning deficit in schizophrenia patients (mean effect size: ; 95% confidence interval 0.56-0.78) that was moderated by task difficulty in terms of the minimum number of moves required for a solution. The results did not reveal any significant relationship between the extent of planning deficits and sociodemographic or clinical variables. CONCLUSIONS: The current results provide first meta-analytic evidence for the commonly assumed impairments of planning performance in schizophrenia. Deficits are more likely to become manifest in problem items with higher demands on planning ahead, which may at least partly explain the heterogeneity of previous findings. As only a small fraction of studies reported coherent information on sample characteristics, future meta-analyses would benefit from more systematic reports on those variables.

[Communication Test for Foreign Physicians in Germany: The Patient Communication Test]. / Kommunikationsprüfung ausländischer Ärzte in Deutschland: Patientenkommunikationstest.

INTRODUCTION: The number of foreign doctors in Germany has increased steadily in recent years. To obtain the German medical license, sufficient language competence is mandatory. Nevertheless, in practice, foreign doctors have considerable difficulties in their communication with patients, medical colleagues and other health professionals. This can lead to misunderstandings and thus impair patient safety. To overcome this problem, the "patient communication test" was developed and piloted as an additional requirement to be granted license to practice medicine in Germany. The aim of this study is to present our results in the development and piloting of this test. METHODS: 3 OSCE stations (Objective Structured Clinical Examination) were designed, which evaluate communication skills in 3 medical competences: history taking, case presentation and explaining to patients before obtaining informed consent. After extensive instruction of actors as patients and raters on the basis of the evaluation criteria, the communication test was subjected to pilot studies in 6 different cities (Freiburg, Jena, Mainz, Mannheim, Tübingen, and Ulm). RESULTS: In 2013, 639 foreign doctors participated in the test; 461 (72.14%) of these doctors passed the test on their first try, 51 (7.98%) on their second attempt and 6 (0.93%) on their third try. CONCLUSION: The patient communication test evaluates the communication skills of foreign doctors in OSCE-setting using standardized actor-patients. This improves the communication skills and enhances patient safety in the German health care system by smooth inter-professional and patient-centered communication.

[An approach to solving the problem of missing data: identifying and dealing with mechanisms adequately]. / Lösungsansätze für das Problem fehlender Werte: Mechanismen erkennen und adäquat behandeln.

Being confronted with missing data, the most important step is the knowledge of the underlying mechanism. In consequence of this, modern missing data techniques in contrast to past techniques are presented and compared, which can deal with more common situations. Finally, concrete instructions for the correct treatment of missing data are given.

Dementia quality of life instrument--construct and concurrent validity in patients with mild to moderate dementia.

BACKGROUND AND PURPOSE: To translate the Dementia quality of life instrument (DQoL) into German and assess its construct and concurrent validity in community-dwelling people with mild to moderate dementia. METHODS: Dementia quality of life instrument data of two pooled samples (n=287) were analysed regarding ceiling and floor effects, internal consistency, factor reliability and correlations with corresponding scales on quality of life (Quality of Life in Alzheimer's Disease and SF-12), cognition (Mini-Mental State Examination, Alzheimer's Disease Assessment Scale - cognitive), depression (Cornell Scale for Depression in Dementia) and activities of daily living (Interview of Deterioration in Daily Living Activities in Dementia). RESULTS: We found no floor effects (<2%), minor ceiling effects (1-11%), moderate to good internal consistency (Cronbach's α: 0.6-0.8) and factor reliability (0.6-0.8), moderate correlations with self-rated scales of quality of life (Spearman coefficient: 0.3-0.6) and no or minor correlations with scores for cognition, depression or activities of daily living (r<0.3). The original five-factor model could not be confirmed. CONCLUSION: The DQoL can be used in dementia research for assessing positive and negative affect, feelings of belonging and self-esteem. The findings suggest further research to improve the structure of the scales aesthetics, feelings of belonging and self-esteem.

Perceived conflicts and errors in complex problem solving.

In a behavioral experiment on 60 healthy volunteers, the Tower of London was employed as a complex visuo-spatial planning task. After each trial, participants were asked how difficult they found the task and whether they thought their solution was optimal. Results showed that objective problem difficulty affected behavioral performance as well as subjectively experienced difficulty and performance certainty. This pattern was influenced by experimental manipulation of participants' knowledge of objective problem difficulty: For optimally solved problems, performance certainty remained at high levels if such knowledge was provided, and strongly declined in more difficult problems if it was withheld. For nonoptimally solved problems, subjects' ratings indicated awareness of errors when they were informed about objective problem difficulty; otherwise, performance certainty declined from intermediate to low levels in more difficult problems. No such interaction was observed with regard to ratings of subjective problem difficulty. Additional structural equation modeling revealed that subjective awareness of errors and processing conflicts can be considered as independent only for optimally solved trials in which the optimal solution was known to the participants. We conclude that participants' ratings of problem difficulty and performance certainty can be regarded as indicators of at least partly distinct processes of performance monitoring, and that studies of complex problem solving incorporating such subjective measures may enhance the empirical basis of current theories of executive functioning.

[Organization of methodological support and cross-project research activities in multicenter research programmes - experiences of the centers for methodological support within the "rehabilitation science" research network]. / Organisation methodischer Beratung und projektübergreifender Forschungsaktivitäten in multizentrischen Forschungsprogrammen - Erfahrungen der Methodenzentren im Verbundforschungsprogramm Rehabilitationswissenschaften.

On completion of the funding period of six years within the federal programme for research in medical rehabilitation, an evaluative summary is given of the work performed and the experiences made in the cross-sectional projects offering methodological support. While specific research profiles had prevailed in each of the eight regional research networks, two institutions had been implemented with similar task assignments within all networks; i. e., (i) a central office, and (ii) a center for methodological support (CMS) had been available in order to enhance methodological research infrastructure and research quality of the clinical projects. This article outlines the support offered as well as further tasks of the CMS. Further, it is argued that organized, scientifically based methodological support and consultation should be part of any research network. Finally, a number of important aspects are discussed which should be taken into account to enhance research quality in medical rehabilitation in the future.

[Speech therapy assessment: field study on psychometric properties, practicability, acceptance and process quality]. / Das logopädische Assessment: Feldversuch zu psychometrischen Eigenschaften, Praktikabilität, Akzeptanz und Prozessqualität.

OBJECTIVE: to investigate the internal consistency, responsiveness, discriminative validity, practicability, acceptance and process quality of a recently developed Speech Therapy Assessment (STA) under routine work conditions of speech and language therapists in German speaking countries. Since standardised, generic and ICF-oriented assessment tools for documentation and evaluation of speech therapy interventions for adult clients are missing in German speaking countries and existing tests cover only sub-areas, the STA has been developed in the years 1995 to 2002. By means of different domains, speech and language therapists assess client (1) communication, (2) aphasia, (3) speech apraxia, (4) dysarthria and (5) dysphagia as well as (6) her or his dealing with corresponding disabilities. METHODS: 17 therapists from 14 institutions applied the STA to 260 adult clients with language, speaking or swallowing disorders. The clients were included in the study consecutively over a period of 7 month. After this period, the therapists completed a questionnaire regarding the benefit and practicability of the STA. Cronbach alpha was calculated as indicator for internal consistency, effect sizes (standardised response means) for responsiveness and ROC values for discriminative validity. The answers of the questionnaire about the benefit of the STA were evaluated both, quantitatively and qualitatively. RESULTS: The internal consistency and discriminative validity were high (Cronbach alpha: 0.79 to 0.95; ROC-values: 0.84 to 0.98). Effect sizes regarding responsiveness were moderate (standardised response means: 0.46 to 0.78). On a 5-step Likert scale (1 = very good, 5 = inadequate), the therapists rated the average (standard deviation) benefit of the STA with: practicability 2.6 (1.2), acceptance 2.8 (1.3), impact on diagnostics 2.8 (1.3), impact on finding therapeutic goals 3.5 (1.2), impact on communication with other rehabilitation partners 2.7 (1.5) and overall judgement 2.6 (0.9). CONCLUSION: The STA fulfils essential quality criteria of the classical test theory. The involved therapists assessed the benefit of the STA as satisfactory. In addition, they pointed out concrete improvement potential for the implementation in practice. It is planed to investigate a refined version of the STA in a multi centre validation study.

[An empirical structural analysis of the IRES questionnaire version 2, dependent on indication, gender and age]. / Eine empirische Strukturanalyse des IRES-Patientenfragebogens Version 2 in Abhängigkeit von Indikation, Geschlecht und Alter.

The patient questionnaire "Indicators of Reha Status" (IRES, Version 2) is used for assessing the need for rehabilitation and the success of rehabilitation. It is one of the most frequently used questionnaires in measuring subjective health conditions in medical rehabilitation in Germany. Based on the data of 8600 inpatient rehabilitees, the underlying structural model is examined by a confirmatory factor analysis. The model deviates in part from the original model of the questionnaire authors. The modified model was tested within 12 sub-groups. The sub-groups were divided depending on sex, age and indications (orthopaedic, cardiologic and psychosomatic) of the patients. Multi-group comparisons made between those 12 sub-groups showed specific structures within the groups of psychosomatic patients while no differences between female/male and younger/older patients were found. Furthermore, comparable structures of orthopaedic and cardiologic patients were found. Therefore the dimension values of the IRES patient questionnaire are not suited for a comparison between psychosomatic patients and patients from the somatic indications.

Planning abilities and the Tower of London: is this task measuring a discrete cognitive function?

The Tower of London (ToL) test is widely used for measuring planning and aspects of problem solving. The primary focus of this study was to asses the relationship among different measures on the ToL. A secondary purpose was to examine the putative relationship between intelligence and working memory with that of ToL performance. Analyses of the interrelation of several ToL parameters indicated that better ToL performance was associated with longer preplanning time and shorter movement execution time. Good performers showed a stronger increase in preplanning duration with task difficulty then intermediate or poor planners. Stepwise multiple regression analysis yield fluid intelligence as the only significant predictor of ToL performance. These result suggest that the Tower of London assesses predominantly planning and problem solving and could not be explained by other cognitive domains.

[Estimating effect sizes in clinical trials]. / Effektgrössenberechnung bei Interventionsstudien.

Even though reporting of effect sizes is recommended in methodological guidelines such as the CONSORT Statement (Consolidated Standard of Reporting Trials), these quantities are still rarely included in reports on studies in rehabilitation medicine. The aim of this paper is to emphasize the relevance of reporting effect sizes and to illustrate different methods for their calculation. The implications of using different methods for calculating effect sizes are also discussed.

The Tower of London: the impact of instructions, cueing, and learning on planning abilities.

The Tower of London (ToL) is a well-known test of planning ability, and commonly used for the purpose of neuropsychological assessment and cognitive research. Its widespread application has led to numerous versions differing in a number of respects. The present study addressed the question whether differences in instruction, cueing, and learning processes systematically influence ToL performance across five difficulty levels (three to seven moves). A total of 81 normal adults were examined in a mixed design with the between-subject factor instruction (online versus mental preplanning) and the within-subject factors cueing (cue versus non-cue test version) and learning processes (first block and second block). We also assessed general intelligence for further analyses of differences between instruction groups. In general, there was a significant main effect across the difficulty levels indicating that the rate of incorrect solutions increased with problem difficulty. The participants who were instructed to make full mental plans before beginning to execute movements (preplanning) solved significantly more problems than people who started immediately with task-related movements (online). As for the cueing conditions, participants with the minimum number of moves predetermined (cue) could solve more trials than people who were only instructed to solve the problems in as few moves as possible (non-cue). Participants generally increased performance in the second part of the test session. However, an interaction of presentation order of the cueing condition with learning indicated that people who started the tasks with the non-cue version showed significantly better performance in the following cue condition, while participants who started with the cue condition stayed at the same performance level for both versions. These findings suggest that instruction, cueing conditions, and learning processes are important determinants of ToL performance, and they stress the necessity of standardized application in research and clinical practice.

Global analysis of Escherichia coli gene expression during the acetate-induced acid tolerance response.

The ability of Escherichia coli to survive at low pH is strongly affected by environmental factors, such as composition of the growth medium and growth phase. Exposure to short-chain fatty acids, such as acetate, proprionate, and butyrate, at neutral or nearly neutral pH has also been shown to increase acid survival of E. coli and Salmonella enterica serovar Typhimurium. To investigate the basis for acetate-induced acid tolerance in E. coli O157:H7, genes whose expression was altered by exposure to acetate were identified using gene arrays. The expression of 60 genes was reduced by at least twofold; of these, 48 encode components of the transcription-translation machinery. Expression of 26 genes increased twofold or greater following treatment with acetate. This included six genes whose products are known to be important for survival at low pH. Five of these genes, as well as six other acetate-induced genes, are members of the E. coli RpoS regulon. RpoS, the stress sigma factor, is known to be required for acid tolerance induced by growth at nonlethal low pH or by entry into stationary phase. Disruption of the rpoS gene by a transposon insertion mutation also prevented acetate-induced acid tolerance. However, induction of RpoS expression did not appear to be sufficient to activate the acid tolerance response. Treatment with either NaCl or sodium acetate (pH 7.0) increased expression of an rpoS::lacZ fusion protein, but only treatment with acetate increased acid survival.