Oliver Hirsch

German validation of the Conners Adult ADHD Rating Scales-self-report (CAARS-S) I: factor structure and normative data.

BACKGROUND Attention-deficit/hyperactivity disorder (ADHD) often persists into adulthood. Instruments for diagnosing ADHD in childhood are well validated and reliable, but diagnosis of ADHD in adults remains problematic. Attempts have been made to develop criteria specific for adult ADHD, resulting in the development of self-report and observer-rated questionnaires. To date, the Conners Adult ADHD Rating Scales (CAARS) are the international standard for questionnaire assessment of ADHD. The current study evaluates a German version of the CAARS self-report (CAARS-S). METHODS Eight hundred and fifty healthy German control subjects were recruited to fill out the CAARS-S and to answer questions on sociodemographic variables. Explorative and confirmative factor analyses were conducted to obtain the factor structure for the German model and to replicate the factor structure of the original American model. Analyses on gender, age, and education level were calculated for normative data. RESULTS The explorative factor analysis of the German sample results in a six-factor solution that explained 52% of the variance. A confirmative analysis that was based on the 42 items of the original American model showed a high model-fit. Analyses of normative data showed significant influences of age, gender, and education level on the emerging subscales. CONCLUSION Even though the explorative factor analysis yields a solution different from the American original, the confirmative factor analysis results in such a high model-fit that use of the American version is justified with respect to international multicenter studies, for which this instrument will be highly valuable.

German Validation of the Conners Adult ADHD Rating Scale–Self-Report: Confirmation of Factor Structure in a Large Sample of Participants with ADHD

Objective: The Conners Adult ADHD Rating Scales (CAARS) assess symptoms specific to adults that are frequently used and have been translated into German. The current study tests the factor structure of the CAARS in a large sample of German adults with ADHD and compares the means of the CAARS subscales with those of healthy German controls. Method: CAARS were completed by 466 participants with ADHD and 851 healthy control participants. Confirmatory factor analysis was used to establish model fit with the American original. Comparisons between participants with ADHD and healthy controls and influences of gender, age, and degree of education were analyzed. Results: Confirmatory factor analysis showed a very good fit with the model for the American original. Differences between ADHD participants and healthy controls on all Conners Adult ADHD Rating Scales–Self-Report (CAARS-S) subscales were substantial and significant. Conclusion: The factor structure of the original American model was successfully replicated in this sample of adult German ADHD participants.

Low back pain patient subgroups in primary care: pain characteristics, psychosocial determinants, and health care utilization.

Objectives:In industrialized countries, low back pain (LBP) is one of the leading causes for prolonged sick leave, early retirement, and high health care costs. Providing the same treatments to all patients is neither effective nor feasible, and may impede patients’ recovery. Recent studies have outlined the need for subgroup-specific treatment allocation. Methods:This is a cross-sectional study that used baseline data from consecutively recruited patients participating in a guideline implementation trial regarding LBP in primary care. Classification variables were employment status, age, pain intensity, functional capacity (HFAQ), depression (CES-D), belief that activity causes pain (FABQ subscale), 2 scales of the SF-36 (general health, vitality), and days in pain per year. We performed k-means cluster analyses and split-half cross-validation. Subsequently, we investigated whether the resulting groups incurred different direct and indirect costs during a 6-month period before the index consultation. Results:A 4-cluster solution showed good statistical quality criteria, even after split-half cross-validation. “Elderly patients adapted to pain” (cluster 1) and “younger patients with acute pain” (cluster 4) accounted for 55% of all patients. Cluster validation showed the lowest direct and indirect costs in these groups. About 72% of total costs per patient referred to clusters 2 and 3 (“patients with chronic severe pain with comorbid depression” and “younger patients with subacute pain and emotional distress”). Discussion:Our study adds substantially to the knowledge of LBP-related case-mix in primary care. Information on differential health care needs may be inferred from our study, enabling decision makers to allocate resources more appropriately and to reduce costs.

Reliable classification: Learning classifiers that distinguish aleatoric and epistemic uncertainty

A proper representation of the uncertainty involved in a prediction is an important prerequisite for the acceptance of machine learning and decision support technology in safety-critical application domains such as medical diagnosis. Despite the existence of various probabilistic approaches in these fields, there is arguably no method that is able to distinguish between two very different sources of uncertainty: aleatoric uncertainty, which is due to statistical variability and effects that are inherently random, and epistemic uncertainty which is caused by a lack of knowledge. In this paper, we propose a method for binary classification that does not only produce a prediction of the class of a query instance but also a quantification of the two aforementioned sources of uncertainty. Despite being grounded in probability and statistics, the method is formalized within the framework of fuzzy preference relations. The usefulness and reasonableness of our approach is confirmed on a suitable data set with information about patients suffering from chest pain.

Chronic low back pain patient groups in primary care – A cross sectional cluster analysis

BackgroundDue to the heterogeneous nature of chronic low back pain (CLBP), it is necessary to identify patient groups and evaluate treatments within these groups. We aimed to identify groups of patients with CLBP in the primary care setting.MethodsWe performed a k-means cluster analysis on a large data set (n = 634) of primary care patients with CLBP. Variables of sociodemographic data, pain characteristics, psychological status (i.e., depression, anxiety, somatization), and the patient resources of resilience and coping strategies were included.ResultsWe found three clusters that can be characterized as “pensioners with age-associated pain caused by degenerative diseases”, “middle-aged patients with high mental distress and poor coping resources”, and “middle-aged patients who are less pain-affected and better positioned with regard to their mental health”.ConclusionsOur results supported current knowledge concerning groups of CLBP patients in primary care. In particular, we identified a group that was most disabled and distressed, and which was mainly characterized by psychological variables. As shown in our study, pain-related coping strategies and resilience were low in these patients and might be addressed in differentiating treatment strategies. Future studies should focus on the identification of this group in order to achieve effective treatment allocation.Trial registrationGerman Clinical Trial Register DRKS00003123

Comparison of Web-Based and Paper-Based Administration of ADHD Questionnaires for Adults

Background Satisfactory psychometric properties in offline questionnaires do not guarantee the same outcome in Web-based versions. Any construct that is measured online should be compared to a paper-based assessment so that the appropriateness of online questionnaire data can be tested. Little research has been done in this area regarding Attention-Deficit/Hyperactivity Disorder (ADHD) in adults. Objective The objective was to simultaneously collect paper-based and Web-based ADHD questionnaire data in adults not diagnosed with ADHD in order to compare the two data sources regarding their equivalence in raw scores, in measures of reliability, and in factorial structures. Methods Data from the German versions of the Connors Adult ADHD Rating Scales (CAARS-S), the Wender Utah Rating Scale (WURS-k), and the ADHD Self Rating Scale (ADHS-SB) were collected via online and paper questionnaires in a cross-sectional study with convenience sampling. We performed confirmatory factor analyses to examine the postulated factor structures in both groups separately and multiple group confirmatory factor analyses to test whether the postulated factor structures of the questionnaires were equivalent across groups. With Cronbach alpha, we investigated the internal consistency of the postulated factors in the different questionnaires. Mann-Whitney U tests with the effect size “Probability of Superiority (PS)” were used to compare absolute values in the questionnaires between the two groups. Results In the paper-based sample, there were 311 subjects (73.3% female); in the online sample, we reached 255 subjects (69% female). The paper-based sample had a mean age of 39.2 years (SD 18.6); the Web-based sample had a mean age of 30.4 years (SD 10.5) and had a higher educational background. The original four factor structure of the CAARS-S could be replicated in both samples, but factor loadings were different. The Web-based sample had significantly higher total scores on three scales. The five-factor structure of the German short form of the WURS-k could be replicated only in the Web-based sample. The Web-based sample had substantially higher total scores, and nearly 40% of the Web-based sample scored above the clinically relevant cut-off value. The three-factor structure of the ADHS-SB could be replicated in both samples, but factor loadings were different. Women in the Web-based sample had substantially higher total scores, and 30% of the Web-based sample scored above the clinically relevant cut-off value. Internal consistencies in all questionnaires were acceptable to high in both groups. Conclusions Data from the Web-based administration of ADHD questionnaires for adults should not be used for the extraction of population norms. Separate norms should be established for ADHD online questionnaires. General psychometric properties of ADHD questionnaires (factor structure, internal consistency) were largely unaffected by sampling bias. Extended validity studies of existing ADHD questionnaires should be performed by including subjects with a diagnosis of ADHD and by randomizing them to Web- or paper-based administration.

Satisfaction of Patients and Primary Care Physicians With Shared Decision Making

Satisfaction with treatment is regarded as an important outcome measure, but its suitability has not been thoroughly investigated in the context of shared decision making (SDM). The authors evaluated whether both patients’ and physicians’ satisfaction ratings differ between an intervention group and a control group within a structured tool for cardiovascular prevention (ARRIBA-Herz). In a pragmatic, cluster-randomized, controlled trial, 44 family physicians in the intervention group consecutively recruited 550 patients whereas 47 physicians in the control group included 582 patients. Main findings were high satisfaction ratings independent of group allocation in patients and physicians. Significant differences had only negligible effect sizes. Compared to global satisfaction ratings, the effects of the shared decision-making process are better measured by a more concrete approach representing different steps of this process. Further research should refine behaviorally oriented questionnaires that measure SDM and a version for physicians should also be created.

Faking ADHD? Symptom Validity Testing and Its Relation to Self-Reported, Observer-Reported Symptoms, and Neuropsychological Measures of Attention in Adults With ADHD

Objective: To compare ADHD patients who failed a symptom validity test with those who passed the test to explore whether there are signs of negative response bias on group level. Method: In our outpatient department, 196 adults were diagnosed with ADHD using a comprehensive diagnostic strategy featuring a detailed clinical history, clinical interview, observer rating, several self-rating scales, and neuropsychological attention tests. The Amsterdam Short Term Memory Test (AKGT) was applied as a symptom validity measure. Results: Sixty-three patients (32.1%) scored below the AKGT cutoff level. The two groups did not significantly differ regarding self-report and observer ratings. Those who failed the AKGT had higher reaction time variabilities in selective, auditory and visual divided attention, and higher omission errors in sustained attention. Conclusion: We found no strong indicators for negative response bias in ADHD patients who failed a symptom validity test. New measures and approaches to detect feigned ADHD should be developed.

Reliability and validity of the German version of the OPTION scale.

Objective  To examine the psychometric properties of the German version of the ‘observing patient involvement’ scale (OPTION) by analysing video recordings of primary care consultations dealing with counselling in cardiovascular prevention.

Measurement Equivalence of Four Psychological Questionnaires in Native-Born Germans, Russian-Speaking Immigrants, and Native-Born Russians

Psychological constructs depend on cultural context. It is therefore important to show the equivalence of measurement instruments in cross-cultural research. There is evidence that in Russian-speaking immigrants, cultural and language issues are important in health care. We examined measurement equivalence of the Patient Health Questionnaire-9 (PHQ-9), the Patient Health Questionnaire-15 (PHQ-15), the Hamburg Self-Care Questionnaire (HamSCQ), and the questionnaire on communication preferences of patients with chronic illness (KOPRA) in native-born Germans, Russian-speaking immigrants living in Germany, and native-born Russians living in the former Soviet Union (FSU). All four questionnaires fulfilled requirements of measurement equivalence in confirmatory factor analyses and analyses of differential item functioning. The Russian translations can be used in Russian-speaking immigrants and native-born Russians. This offers further possibilities for cross-cultural research and for an improvement in health care research in Russian-speaking immigrants in Germany. The most pronounced differences occurred in the KOPRA, which point to differences in German and Russian health care systems.