Nerve cross-sectional area from childhood to old age: A high-resolution nerve ultrasound study.

BACKGROUND AND PURPOSE: Nerve cross-sectional area (CSA) is not constant over the human lifespan. The relationship between an increasing CSA and age has been described as a linear positive correlation, but few studies have found a linear decrease in nerve size with older age. The aim of the present study was to analyze the development of nerve CSA in a healthy population from early childhood to old age using high-resolution ultrasound. METHODS: The median, ulnar, radial and sural nerves were examined bilaterally at 18 nerve sites in 110 healthy children, adolescents and adults aged between 2 and 98 years. The CSA of every nerve site was evaluated separately and in different age groups. The correlation of CSA with age, height and weight was analyzed in a linear, logarithmic and quadratic model and correlation coefficients were compared in a goodness-of-fit analysis. Models were then adjusted for weight and height. RESULTS: Linear CSA-age correlations showed the lowest correlation coefficients for all nerve sites. An inverted parabolic curve suggesting a quadratic correlation of CSA and age was the best-fitting model. Weight and height had a higher predictive value than age in adjusted models. CONCLUSIONS: There is an increase in nerve size during childhood and adolescence and a trend towards a decrease in old age, suggesting an inverted parabolic curve partly explained by age-related changes in weight and height. Enlarged nerves in elderly individuals should not be attributed to age alone.

Career and life planning in the context of the postgraduate medical training - current challenges and opportunities.

Introduction: The possibility of balancing career and family is meanwhile a central concern for most physicians when choosing a job. The aim of this study was to identify current barriers and opportunities for physician education and career planning. Methods: This cross-sectional study was conducted as an online survey between 11/2021 and 02/2022 and targeted physicians at all career levels in Germany who were members of a clinical professional association. Alternative and consent questions were used to assess experiences/attitudes toward various aspects of life and career planning, as well as alternative work and parental leave models, depending on gender, specialty, and hierarchical level. Results: The majority of the 2060 participants were female (69%) and had children (66%). Many childless residents reported that they felt they had to choose between children and a career. The majority of female residents, specialists and attending physicians (Ø 55.5%) stated that they had experienced career losses as a result of taking parental leave, while most men did not share this experience (Ø 53.7%). 92% of all participants agreed with the statement that men and women have different career opportunities. Job-sharing models were considered feasible at all levels of the hierarchy by an average of 55.6% of all medical executives. Conclusion: Parenthood and the use of parental leave and part-time work appear to have a significant impact on the career paths of those surveyed. Although the majority of directors of medical training programs are open to job-sharing models, further measures are needed in order to equalize career opportunities for men and women.

Visualizing the (Causal) Effect of a Continuous Variable on a Time-To-Event Outcome.

Visualization is a key aspect of communicating the results of any study aiming to estimate causal effects. In studies with time-to-event outcomes, the most popular visualization approach is depicting survival curves stratified by the variable of interest. This approach cannot be used when the variable of interest is continuous. Simple workarounds, such as categorizing the continuous covariate and plotting survival curves for each category, can result in misleading depictions of the main effects. Instead, we propose a new graphic, the survival area plot, to directly depict the survival probability over time and as a function of a continuous covariate simultaneously. This plot utilizes g-computation based on a suitable time-to-event model to obtain the relevant estimates. Through the use of g-computation, those estimates can be adjusted for confounding without additional effort, allowing a causal interpretation under the standard causal identifiability assumptions. If those assumptions are not met, the proposed plot may still be used to depict noncausal associations. We illustrate and compare the proposed graphics to simpler alternatives using data from a large German observational study investigating the effect of the Ankle-Brachial Index on survival. To facilitate the usage of these plots, we additionally developed the contsurvplot R-package, which includes all methods discussed in this paper.

Risk factors for the deterioration of pulmonary function in primary ciliary dyskinesia.

BACKGROUND: PCD is a genetic disease leading to a decline in pulmonary function. There is only little knowledge of factors determining the long-term pulmonary outcome. Especially adherence has not been addressed yet although being an independent risk factor for an increased loss of lung capacity in other chronic respiratory diseases. OBJECTIVE: Assessing the impact of bacterial airway colonization and adherence on long-term lung function in patients with PCD. METHODS: Data on colonization and lung function parameters like forced expiratory volume in the first second (FEV1, Z-score) and lung clearance index (LCI2,5% ) were collected for 7.01 ± 2.2 years (893 quarters) in 44 PCD patients. Adherence was classified as good, moderate or poor. The impact of both adherence and colonization was assessed for the long-term course of FEV1, the association of colonization with lung function also quarterly. STATISTICS: Kruskall-Wallis test, T test, ANOVA, linear regression, linear mixed model. RESULTS: Chronic colonization did not show any impact on the for long-term course of FEV1 , but adherence was a significant factor: patients with good adherence showed better FEV1 at the end of the observation period than children with poor adherence (-0.15 ± 0.88 vs. -2.63 ± 1.79, p < 0.01). CONCLUSION: Adherence has not yet been investigated for PCD. However, we found it to be a major significant factor affecting long-term FEV1 in PCD. Thus, it should be taken into consideration in the treatment protocols for PCD.

A comparison of different methods to adjust survival curves for confounders.

Treatment specific survival curves are an important tool to illustrate the treatment effect in studies with time-to-event outcomes. In non-randomized studies, unadjusted estimates can lead to biased depictions due to confounding. Multiple methods to adjust survival curves for confounders exist. However, it is currently unclear which method is the most appropriate in which situation. Our goal is to compare forms of inverse probability of treatment weighting, the G-Formula, propensity score matching, empirical likelihood estimation and augmented estimators as well as their pseudo-values based counterparts in different scenarios with a focus on their bias and goodness-of-fit. We provide a short review of all methods and illustrate their usage by contrasting the survival of smokers and non-smokers, using data from the German Epidemiological Trial on Ankle-Brachial-Index. Subsequently, we compare the methods using a Monte-Carlo simulation. We consider scenarios in which correctly or incorrectly specified models for describing the treatment assignment and the time-to-event outcome are used with varying sample sizes. The bias and goodness-of-fit is determined by taking the entire survival curve into account. When used properly, all methods showed no systematic bias in medium to large samples. Cox regression based methods, however, showed systematic bias in small samples. The goodness-of-fit varied greatly between different methods and scenarios. Methods utilizing an outcome model were more efficient than other techniques, while augmented estimators using an additional treatment assignment model were unbiased when either model was correct with a goodness-of-fit comparable to other methods. These "doubly-robust" methods have important advantages in every considered scenario.

[Positive experiences of specialist assistants and physicians with respect to the delegation research project StaerkeR : Evaluation of the training and experiences within the framework of this project]. / Positive Erfahrungen von Fachassistent:innen und Ärzt:innen hinsichtlich des Delegations-Forschungsprojekts StärkeR : Evaluation der Schulung und Erfahrungen im Rahmen dieses Projekts.

INTRODUCTION: The delegation of medical services to rheumatology assistants (RFA) has proven to be safe and effective in the evaluation of the research project "StaerkeR". Afterwards, the experiences of the participating RFAs and rheumatologists with delegation were surveyed and discussed within the framework of an opinion research project. METHODS: At the end of the project, the participating RFAs and rheumatologists were surveyed via an online questionnaire (quantitative analysis) (21 questions for physicians and 44 questions for RFAs). In addition, focus group meetings were held for the RFAs, which were led by a moderator and a secretary. The results of the focus group sessions (qualitative analyses) were analyzed according to the structured method of Kuckartz. RESULTS: All 31 RFAs and 25 rheumatologists involved in the project participated in the online surveys and 9 RFAs took part in the 2 focus groups. In the online surveys, both the RFAs and the rheumatologists gave predominantly good to very good ratings with respect to RFA training, the implementation of delegation in the practices and outpatient clinics, the role of the RFAs and the overall evaluation of the delegation concept. In the focus group discussions, many possible limitations regarding acceptance and implementation of the delegation concept were mentioned. CONCLUSION: The delegation of medical tasks to RFAs is a concept that is positively assessed and highly accepted by both sides, the rheumatologists and the RFAs. In a comparison between the individual practices and hospital outpatient departments, there is still a clear heterogeneity with respect to the willingness and logistical possibilities in the implementation of the delegation concept.

Complete mesocolic excision for right colonic cancer: prospective multicentre study.

BACKGROUND: Complete mesocolic excision (CME) for right colonic cancer is a more complex operation than standard right hemicolectomy but evidence to support its routine use is still limited. This prospective multicentre study evaluated the effect of CME on long-term survival in colorectal cancer centres in Germany (RESECTAT trial). The primary hypothesis was that 5-year disease-free survival would be higher after CME than non-CME surgery. A secondary hypothesis was that there would be improved survival of patients with a mesenteric area greater than 15 000 mm2. METHODS: Centres were asked to continue their current surgical practices. The surgery was classified as CME if the superior mesenteric vein was dissected; otherwise it was assumed that no CME had been performed. All specimens were shipped to one institution for pathological analysis and documentation. Clinical data were recorded in an established registry for quality assurance. The primary endpoint was 5-year overall survival for stages I-III. Multivariable adjustment for group allocation was planned. Using a primary hypothesis of an increase in disease-free survival from 60 to 70 per cent, a sample size of 662 patients was calculated with a 50 per cent anticipated drop-out rate. RESULTS: A total of 1004 patients from 53 centres were recruited for the final analysis (496 CME, 508 no CME). Most operations (88.4 per cent) were done by an open approach. Anastomotic leak occurred in 3.4 per cent in the CME and 1.8 per cent in the non-CME group. There were slightly more lymph nodes found in CME than non-CME specimens (mean 55.6 and 50.4 respectively). Positive central mesenteric nodes were detected more in non-CME than CME specimens (5.9 versus 4.0 per cent). One-fifth of patients had died at the time of study with recorded recurrences (63, 6.3 per cent), too few to calculate disease-free survival (the original primary outcome), so overall survival (not disease-specific) results are presented. Short-term and overall survival were similar in the CME and non-CME groups. Adjusted Cox regression indicated a possible benefit for overall survival with CME in stage III disease (HR 0.52, 95 per cent c.i. 0.31 to 0.85; P = 0.010) but less so for disease-free survival (HR 0.66; P = 0.068). The secondary outcome (15 000 mm2 mesenteric size) did not influence survival at any stage (removal of more mesentery did not alter survival). CONCLUSION: No general benefit of CME could be established. The observation of better overall survival in stage III on unplanned exploratory analysis is of uncertain significance.

The Structured Delegation of Medical Care Services for Patients With Inflammatory Rheumatic Diseases.

BACKGROUND: In some areas of Germany, there is a shortage of specialist physicians for patients with inflammatory rheumatic diseases. Delegating certain medical care services to qualified, specialized rheumatological assistants (SRAs) might be an effective way to supplement the available capacity for specialized medical care. METHODS: Patients under stable treatment for rheumatoid arthritis (RA) or psoriatic arthritis (PsA) were included in this trial, which was designed to demonstrate, in a first step, the non-inferiority of a form of care involving delegation of physicians' tasks to SRAs (team-based care), in comparison to standard care, with respect to changes in disease activity at one year. "Non-inferiority," in this context, means either superiority or else an irrelevant extent of inferiority. In a second step, in case non-inferiority could be shown, the superiority of team-based care with respect to changes in patients' health-related quality of life would be tested as well. Disease activity was measured with the Disease Activity Score 28, and health-related quality of life with the EQ-5D-5L. This was a randomized, multicenter, rater-blinded trial with two treatment arms (team-based care and standard care). The statistical analysis was performed with mixed linear models (DRKS00015526). RESULTS: From September 2018 to June 2019, 601 patients from 14 rheumatological practices and 3 outpatient rheumatological clinics in the German states of North Rhine-Westphalia and Lower Saxony were randomized to either team-based or standard care. Team-based care was found to be non-inferior to standard care with respect to changes in disease activity (adjusted difference = -0.19; 95% confidence interval [-0.36; -0.02]; p <0.001 for non-inferiority). Superiority with respect to health-related quality of life was not demonstrated (adjusted difference = 0.02 [-0.02; 0.05], p = 0.285). CONCLUSION: Team-based care, with greater integration of SRAs, is just as good as standard care in important respects. Trained SRAs can effectively support rheumatologists in the care of stable patients with RA or PsA.

Causes of mortality in elderly UICC stage III colon cancer (CC) patients--Tumor-related death and competing risks from the German AIO colorectal study group Colopredict Plus (CPP) registry.

BACKGROUND: Colon cancer (CC) is a disease of elderly patients (pts.) with a median age of 73 years (yrs.). Lack of data about the effects of adjuvant chemotherapy (ACT) is caused by underrepresentation of this clinically relevant cohort in interventional trials. We analyzed real-world data from the German CPP registry with regard to a possible benefit of ACT in elderly (70+ yrs.) versus younger pts. (50 to <70 yrs.) taking cause-specific deaths into account. METHODS: We analyzed the effect of age and ACT on overall survival (OS) and cause-specific death of stage III pts. using Cox regression. RESULTS: In total, 1558 pts. were analyzed and follow-up was 24.6 months. 62.6% of the elderly received ACT whereas 91.1% of younger pts. (p < 0.001). Oxaliplatin combinations were significantly less often given to older than younger pts. (38.8% vs. 88.9%; p < 0.001). Mean Charlson comorbidity score was significantly lower in pts. that received ACT (0.61) than in those without ACT (1.16; p < 0.001). ACT was an independent positive prognostic factor for cancer-related death in elderly pts. even in pts. 75+ yrs. No significant difference in the effect of ACT could be observed between age groups (interaction: cancer-specific death HR = 1.7948, p = 0.1079; death of other cause HR = 0.7384, p = 0.6705). CONCLUSION: ACT was an independent positive prognostic factor for OS. There may be a cohort of elderly with less co-morbidities who benefit from ACT.

Amyloid-ß misfolding as a plasma biomarker indicates risk for future clinical Alzheimer's disease in individuals with subjective cognitive decline.

BACKGROUND: We evaluated Aß misfolding in combination with Aß42/40 ratio as a prognostic tool for future clinical progression to mild cognitive impairment (MCI) or dementia due to Alzheimer's disease (AD) in individuals with subjective cognitive decline (SCD). METHODS: Baseline plasma samples (n = 203) from SCD subjects in the SCIENCe project and Amsterdam Dementia Cohort (age 61 ± 9 years; 57% male, mean follow-up time 2.7 years) were analyzed using immuno-infrared-sensor technology. Within 6 years of follow-up, 22 (11%) individuals progressed to MCI or dementia due to AD. Sensor readout values > 1646 cm- 1 reflected normal Aß folding; readouts at ≤ 1646 cm- 1 reflected low and at < 1644 cm- 1 high misfolding. We used Cox proportional hazard models to quantify Aß misfolding as a prognostic biomarker for progression to MCI and dementia due to AD. The accuracy of the predicted development of MCI/AD was determined by time-dependent receiver operating characteristic (t-ROC) curve analyses that take individual follow-up and conversion times into account. Statistical models were adjusted for age, sex, and APOEε4 status. Additionally, plasma Aß42/40 data measured by SIMOA were statistically analyzed and compared. RESULTS: All 22 patients who converted to MCI or AD-dementia within 6 years exhibited Aß misfolding at baseline. Cox analyses revealed a hazard ratio (HR) of 19 (95% confidence interval [CI] 2.2-157.8) for future conversion of SCD subjects with high misfolding and of 11 (95% CI 1.0-110.1) for those with low misfolding. T-ROC curve analyses yielded an area under the curve (AUC) of 0.94 (95% CI 0.86-1.00; 6-year follow-up) for Aß misfolding in an age, sex, and APOEε4 model. A similar model with plasma Aß42/40 ratio yielded an AUC of 0.92 (95% CI, 0.82-1.00). The AUC increased to 0.99 (95% CI, 0.99-1.00) after inclusion of both Aß misfolding and the Aß42/40 ratio. CONCLUSIONS: A panel of structure- and concentration-based plasma amyloid biomarkers may predict conversion to clinical MCI and dementia due to AD in cognitively unimpaired subjects. These plasma biomarkers provide a noninvasive and cost-effective alternative for screening early AD pathological changes. Follow-up studies and external validation in larger cohorts are in progress for further validation of our findings.