Ludwig-Maximilians-Universität München
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Characteristics of patients with very high fracture risk in a community-dwelling geriatric cohort
Full text linkObjective
Bone anabolic treatment has been shown to be superior to oral bisphosphonates, especially in osteoporosis patients with a very high fracture-risk. The current German osteoporosis guideline classifies the very high 3-year fracture-risk based upon a novel fracture-risk model. As age is a severe risk-factor, we examined the distribution and associations to geriatric assessment parameters of the very high-risk group in a well-characterized cohort of community-dwelling geriatric patients.
Methods
Analyses were based on 166 patients (mean age 82 ± 6 years) taken from MUSAR (MUnich SArcopenia Registry). Fracture-risk was calculated as described in the current German guideline. Thereupon, patients were allocated to the low−/moderate (10 %). Associations of geriatric assessment parameters with the group allocation to the fracture-risk group were evaluated by covariate-adjusted linear regression analysis.
Results
>80 % of the study population were at an increased fracture-risk. Besides, >50 % were allocated to the very high-risk group. Patients in the very high-risk group showed limitations in all physical performance tests (short physical performance battery (SPPB), gaitspeed, handgrip strength and chair rise test). Also, polypharmacy and a risk for malnutrition (from mini nutritional assessment short form (MNA-SF)), were present. All parameters showed significant associations with group allocation to very high-risk group.
Conclusion
Most of the geriatric patients are at a very high-risk for osteoporotic fractures. Also, this group presented several limitations in the comprehensive geriatric assessment highlighting the vulnerability of this group. Clinicians need to reinforce fracture-risk assessment and familiarize with treatment options
Personalization through adaptivity or adaptability? A meta-analysis on simulation-based learning in higher education
Full text linkThis meta-analysis builds on 217 empirical studies in higher education and investigates the role of the different forms of adaptivity and adaptability as personalization strategies in simulation-based learning environments for complex skills in higher education. The strategies used to personalize scaffolding and task progression were the central point in this meta-analysis. We identified conditions under which personalization advances complex skills in higher education. The results indicate that whereas adaptivity (i.e., computer makes decisions) is more effective for scaffolding, adaptability (the decisions made by individual learners) seem more beneficial for task progression. We conclude that adaptivity and adaptability can be effectively used to personalize simulation-based learning environments in higher education to better address needs of learners with different learning needs. We also discuss the potential of artificial intelligence for empowering personalization in simulation-based learning
Inverse Constitutional AI: Compressing Preferences into Principles
Full text linkFeedback data is widely used for fine-tuning and evaluating state-of-the-art AI models. Pairwise text preferences, where human or AI annotators select the “better” of two options, are particularly common. Such preferences are used to train (reward) models or to rank models with aggregate statistics. For many applications it is desirable to understand annotator preferences in addition to modelling them – not least because extensive prior work has shown various unintended biases in preference datasets. Yet, preference datasets remain challenging to interpret. Neither black-box reward models nor statistics can answer why one text is preferred over another. Manual interpretation of the numerous (long) response pairs is usually equally infeasible. In this paper, we introduce the Inverse Constitutional AI (ICAI) problem, formulating the interpretation of pairwise text preference data as a compression task. In constitutional AI, a set of principles (a constitution) is used to provide feedback and fine-tune AI models. ICAI inverts this process: given a feedback dataset, we aim to extract a constitution that best enables a large language model (LLM) to reconstruct the original annotations. We propose a corresponding ICAI algorithm and validate its generated constitutions quantitatively based on annotation reconstruction accuracy on several datasets: (a) synthetic feedback data with known principles; (b) AlpacaEval cross-annotated human feedback data; (c) crowdsourced Chatbot Arena data; and (d) PRISM data from diverse demographic groups. As an example application, we further demonstrate the detection of biases in human feedback data. As a short and interpretable representation of the original dataset, generated constitutions have many potential use cases: they may help identify undesirable annotator biases, better understand model performance, scale feedback to unseen data, or assist with adapting AI models to individual user or group preferences. We release the source code for our algorithm and experiments at https://github.com/rdnfn/icai
A survey of welfare problems associated with transporting horses by road in Germany (2022–2024)
Full text linkEquine road transport is stressful and associated with an increased risk of behavioral problems, injuries, respiratory and gastrointestinal diseases. This cross-sectional survey-based study aimed to describe transport-related practices and the perception of behavioral and health issues in Germany. The survey targeted horse owners (amateurs and professionals) and obtained demographic details, the participant's experience, frequency and duration of transportation, and behavioral and health problems related to equine transportation. Associations among behavioral and health problems and transport parameters were examined with logistic regression analysis. In total, 432 horse owners participated, but only 59.7 % (258 respondents) completed the questionnaire. Most journeys (72.5 %) were < 2 h in duration and 45.8 % fed hay in transit. One-third of respondents observed behavioral and 42.6 % reported health problems. Diarrhea was most common (33.9 %), followed by injuries (19.3 %), muscle disorders (4 %), respiratory problems, and colic (each 2.4 %). Professionals were less likely to observe diarrhea in transported horses than amateurs (OR 1.04). In single transportation, horses were significantly more likely to show behavioral problems than when transported together (OR 0.53, CI 0.35–0.76, P = 0.001). In conclusion, most of the journeys in Germany were short (<2 h). A high rate of behavioral problems was reported, whereas health issues were considerably less frequently observed. This may be associated with management practices, implementation of safety equipment, shorter travel distances, and favorable climatic conditions in comparison to other studies
Sequential and parallel testing for microbiological confirmation of tuberculosis disease in children in five low-income and middle-income countries
Full text linkBackground: Despite causing high mortality worldwide, paediatric tuberculosis is often undiagnosed. We aimed to investigate optimal testing strategies for microbiological confirmation of tuberculosis in children younger than 15 years, including the yield in high-risk subgroups (eg, children younger than 5 years, with HIV, or with severe acute malnutrition [SAM]).
Methods: For this secondary analysis, we used data from RaPaed-TB, a multicentre diagnostic accuracy study evaluating novel diagnostic assays and testing approaches for tuberculosis in children recruited from five health-care centres in Malawi, Mozambique, South Africa, Tanzania, and India conducted between Jan 21, 2019, and June 30, 2021. Children were included if they were younger than 15 years and had signs or symptoms of pulmonary or extrapulmonary tuberculosis; they were excluded if they weighed less than 2 kg, had received three or more doses of anti-tuberculosis medication at time of enrolment, were in a condition deemed critical by the local investigator, or if they did not have at least one valid microbiological result. We collected tuberculosis-reference specimens via spontaneous sputum, induced sputum, gastric aspirate, and nasopharyngeal aspirates. Microbiological tests were Xpert MTB/RIF Ultra (hereafter referred to as Ultra), liquid culture, and Löwenstein-Jensen solid culture, which were followed by confirmatory testing for positive cultures. The main outcome of this secondary analysis was categorising children as having confirmed tuberculosis if culture or Ultra positive on any sample, unconfirmed tuberculosis if clinically diagnosed, and unlikely tuberculosis if neither of these applied.
Findings: Of 5313 children screened, 975 were enrolled, of whom 965 (99%) had at least one valid microbiological result. 444 (46%) of 965 had unlikely tuberculosis, 282 (29%) had unconfirmed tuberculosis, and 239 (25%) had confirmed tuberculosis. Median age was 5·0 years (IQR 1·8-9·0); 467 (48%) of 965 children were female and 498 (52%) were male. 155 (16%) of 965 children had HIV and 110 (11%) children had SAM. 196 (82%) of 239 children with microbiological detection tested positive on Ultra. 110 (46%) of 239 were confirmed by both Ultra and culture, 86 (36%) by Ultra alone, and 43 (18%) by culture alone. 'Trace' was the most common semiquantitative result (93 [40%] of 234). 481 (50%) of 965 children had only one specimen type collected, 99 (21%) of whom had M tuberculosis detected. 484 (50%) of 965 children had multiple specimens collected, 141 (29%) of whom were positive on at least one specimen type. Of the 102 children younger than 5 years with M tuberculosis detected, 80 (78%) tested positive on sputum. 64 (80%) of 80 children who tested positive on sputum were positive on sputum alone; 61 (95%) of 64 were positive on induced sputum, two (3%) of 64 were positive on spontaneous sputum, and one (2%) was positive on both.
Interpretation: High rates of microbiological confirmation of tuberculosis in children can be achieved via parallel sampling and concurrent testing procedures. Sample types and choice of test to be used sequentially should be considered when applying to groups such as children younger than 5 years, living with HIV, or with SAM
Predictors of early disability accumulation in newly diagnosed multiple sclerosis: clinical, imaging and cerebrospinal fluid measures
No full textBackground: A growing arsenal of treatment options for relapsing multiple sclerosis (RMS) emphasises the need for early prognostic biomarkers. While evidence for individual markers exists, comprehensive analyses at the time of diagnosis are sparse.
Methods: Brain and spinal cord lesion numbers, cerebrospinal fluid parameters, initial symptoms, and Expanded Disability Status Scale (EDSS) score were determined at the time of diagnosis. Confirmed disability accumulation (CDA), defined as a sustained EDSS increase over 6 months, was determined during a 5-year follow-up. All-subsets multivariable logistic regression was performed to identify predictors of CDA. Model performance was assessed via receiver operating characteristic analysis, and individual risks were calculated. Analyses were repeated with progression independent of relapse activity (PIRA) as an outcome.
Results: 113/417 (27.1%) people with RMS experienced CDA on follow-up. Intrathecal IgG synthesis, a higher number of spinal cord lesions, age and polysymptomatic manifestation were identified as independent predictors of CDA. The resulting prediction model yielded an area under the curve (AUC) of 0.75 with a 95% CI of 0.70 to 0.80. Individuals exceeding the optimal thresholds for the three most significant predictors had a 61.8% likelihood of experiencing CDA, whereas those below all three thresholds had a CDA rate of 4.5%. The only significant baseline predictor differentiating PIRA from relapse-associated worsening was a higher number of spinal cord lesions (AUC=0.64, 95% CI 0.54 to 0.74).
Conclusions: Intrathecal IgG synthesis, spinal cord lesion number, age and polysymptomatic manifestation are independent predictors of early CDA in newly diagnosed RMS
Perfectionism as a risk factor for psychopathology in a community sample of young women: disorder-specific pathways to disordered eating or obsessive-compulsive symptoms
No full textPerfectionism has been suggested as a risk factor relevant to multiple psychological disorders, including obsessive-compulsive disorder (OCD) and eating disorders (ED). However, it remains unclear how perfectionism contributes to general and specific psychopathology. Disorder-specific processes (e.g. body dissatisfaction, responsibility) between perfectionism and subsequent symptoms may offer an explanation. The current study examined longitudinal associations between perfectionism, body dissatisfaction or responsibility, and symptoms of ED or OCD. A community sample of 499 women (18–30) completed a three-wave online study, assessing perfectionism, ED and OCD symptoms, body dissatisfaction, and responsibility/threat overestimation. Temporal relations between perfectionism and symptoms were analyzed using a structural equation model. Effects of body dissatisfaction and responsibility/threat overestimation were analyzed using multiple hierarchical regressions. Results showed that perfectionism predicted subsequent OCD symptoms, but not ED symptoms. ED symptoms, but not OCD symptoms, predicted subsequent perfectionism. No interaction effects between perfectionism and the disorder-specific processes were found. Instead, body dissatisfaction independently contributed to both ED and OCD symptoms, whereas inflated responsibility/threat overestimation predicted specifically OCD symptoms. To conclude, perfectionism appears to increase the risk of psychological symptoms. However, in this sample this was specific to OCD symptoms. Given ED symptoms predicted later perfectionism, bidirectional effects need to be considered
Contrast Agent Uptake in Endolymphatic Sac and Duct: Inverse Relation to Endolymphatic Hydrops
No full textObjectives: Ménière's disease (MD) and vestibular migraine (VM) can be associated with endolymphatic hydrops (ELH). The differential role of the endolymphatic sac and duct (ES/ED) system for the development of ELH is poorly understood.
Methods: On 251 delayed, contrast-enhanced inner ear MRI (iMRI) datasets from neurotological patients and healthy control participants, we evaluated (1) the visibility of the ES/ED system using a novel semi-quantitative scale, and (2) the dimensions of ELH, calculated using volumetric local thresholding (VOLT). Afterwards, statistical analysis of ES/ED radiologic visibility in relation to the grade of ELH, the degree of clinical symptoms, and audiometric findings was performed.
Results: Patients were divided into an MD cohort (n = 68, 34 females, mean age 54.5 ± 14.8 years) and a VM cohort (n = 67, 42 females, 45.9 ± 15.5 years). The remaining datasets did not fulfill diagnostic criteria for definite diagnoses (n = 64, 27 females, mean age 51.3 ± 16.6) or were from healthy controls (HC; n = 52, 27 females, 49.0 ± 18.1 years). MD patients showed the lowest ES/ED-visibility scores on the affected side (ANOVA F(172,2): 20.60, p < 0.001), while the ES/ED-visibility on the non-affected side in MD patients was still significantly lower than in VM and HC (ANOVA F(172,2): 6.80, p 1.44 × 10−3). The ES/ED-visibility score and ELH volume (determined by VOLT, in mm3) correlated inversely (Spearman's rho: −0.32, Fisher's z −0.34, p < 0.001).
Conclusion: ES/ED radiologic visibility in iMRI is inversely associated with ELH volumes. Patients with MD show substantially decreased ES/ED visibility on the affected ear and (less pronounced) on the unaffected ear, while VM and HC exhibit normal ES/ED visibility