Referring physicians' intention to use hospital report cards for hospital referral purposes in the presence or absence of patient-reported outcomes: a randomized trial

PURPOSE

This study aims to determine the intention to use hospital report cards (HRCs) for hospital referral purposes in the presence or absence of patient-reported outcomes (PROs) as well as to explore the relevance of publicly available hospital performance information from the perspective of referring physicians.

METHODS

We identified the most relevant information for hospital referral purposes based on a literature review and qualitative research. Primary survey data were collected (May-June 2021) on a sample of 591 referring orthopedists in Germany and analyzed using structural equation modeling. Participating orthopedists were recruited using a sequential mixed-mode strategy and randomly allocated to work with HRCs in the presence (intervention) or absence (control) of PROs.

RESULTS

Overall, 420 orthopedists (mean age 53.48, SD 8.04) were included in the analysis. The presence of PROs on HRCs was not associated with an increased intention to use HRCs (p = 0.316). Performance expectancy was shown to be the most important determinant for using HRCs (path coefficient: 0.387, p < .001). However, referring physicians have doubts as to whether HRCs can help them. We identified "complication rate" and "the number of cases treated" as most important for the hospital referral decision making; PROs were rated slightly less important.

CONCLUSIONS

This study underpins the purpose of HRCs, namely to support referring physicians in searching for a hospital. Nevertheless, only a minority would support the use of HRCs for the next hospital search in its current form. We showed that presenting relevant information on HRCs did not increase their use intention.

The elicitation of patient and physician preferences for calculating consumer-based composite measures on hospital report cards: results of two discrete choice experiments

PURPOSE

The calculation of aggregated composite measures is a widely used strategy to reduce the amount of data on hospital report cards. Therefore, this study aims to elicit and compare preferences of both patients as well as referring physicians regarding publicly available hospital quality information METHODS: Based on systematic literature reviews as well as qualitative analysis, two discrete choice experiments (DCEs) were applied to elicit patients' and referring physicians' preferences. The DCEs were conducted using a fractional factorial design. Statistical data analysis was performed using multinomial logit models RESULTS: Apart from five identical attributes, one specific attribute was identified for each study group, respectively. Overall, 322 patients (mean age 68.99) and 187 referring physicians (mean age 53.60) were included. Our models displayed significant coefficients for all attributes (p < 0.001 each). Among patients, "Postoperative complication rate" (20.6%; level range of 1.164) was rated highest, followed by "Mobility at hospital discharge" (19.9%; level range of 1.127), and ''The number of cases treated" (18.5%; level range of 1.045). In contrast, referring physicians valued most the ''One-year revision surgery rate'' (30.4%; level range of 1.989), followed by "The number of cases treated" (21.0%; level range of 1.372), and "Postoperative complication rate" (17.2%; level range of 1.123) CONCLUSION: We determined considerable differences between both study groups when calculating the relative value of publicly available hospital quality information. This may have an impact when calculating aggregated composite measures based on consumer-based weighting.

Suitability and user acceptance of the eResearch system "Prospective Monitoring and Management App (PIA)"-The example of an epidemiological study on infectious diseases

BACKGROUND

The eResearch system "Prospective Monitoring and Management App (PIA)" allows researchers to implement questionnaires on any topic and to manage biosamples. Currently, we use PIA in the longitudinal study ZIFCO (Integrated DZIF Infection Cohort within the German National Cohort) in Hannover (Germany) to investigate e.g. associations of risk factors and infectious diseases. Our aim was to assess user acceptance and compliance to determine suitability of PIA for epidemiological research on transient infectious diseases.

METHODS

ZIFCO participants used PIA to answer weekly questionnaires on health status and report spontaneous onset of symptoms. In case of symptoms of a respiratory infection, the app requested participants to self-sample a nasal swab for viral analysis. To assess user acceptance, we implemented the System Usability Scale (SUS) and fitted a linear regression model on the resulting score. For investigation of compliance with submitting the weekly health questionnaires, we used a logistic regression model with binomial response.

RESULTS

We analyzed data of 313 participants (median age 52.5 years, 52.4% women). An average SUS of 72.0 reveals good acceptance of PIA. Participants with a higher technology readiness score at the beginning of study participation also reported higher user acceptance. Overall compliance with submitting the weekly health questionnaires showed a median of 55.7%. Being female, of younger age and being enrolled for a longer time decreased the odds to respond. However, women over 60 had a higher chance to respond than women under 60, while men under 40 had the highest chance to respond. Compliance with nasal swab self-sampling was 77.2%.

DISCUSSION

Our findings show that PIA is suitable for the use in epidemiologic studies with regular short questionnaires. Still, we will focus on user engagement and gamification for the further development of PIA to help incentivize regular and long-term participation.

A semiparametric approach for meta-analysis of diagnostic accuracy studies with multiple cut-offs

The accuracy of a diagnostic test is often expressed using a pair of measures: sensitivity (proportion of test positives among all individuals with target condition) and specificity (proportion of test negatives among all individuals without target condition). If the outcome of a diagnostic test is binary, results from different studies can easily be summarized in a meta-analysis. However, if the diagnostic test is based on a discrete or continuous measure (e.g., a biomarker), several cut-offs within one study as well as among different studies are published. Instead of taking all information of the cut-offs into account in the meta-analysis, a single cut-off per study is often selected arbitrarily for the analysis, even though there are statistical methods for the incorporation of several cut-offs. For these methods, distributional assumptions have to be met and/or the models may not converge when specific data structures occur. We propose a semiparametric approach to overcome both problems. Our simulation study shows that the diagnostic accuracy is under-estimated, although this underestimation in sensitivity and specificity is relatively small. The comparative approach of Steinhauser et al. is better in terms of coverage probability, but may lead to convergence problems. In addition to the simulation results, we illustrate the application of the semiparametric approach using a published meta-analysis for a diagnostic test differentiating between bacterial and viral meningitis in children.

Meta-analysis of diagnostic accuracy studies with multiple thresholds: Comparison of different approaches

Methods for standard meta-analysis of diagnostic test accuracy studies are well established and understood. For the more complex case in which studies report test accuracy across multiple thresholds, several approaches have recently been proposed. These are based on similar ideas, but make different assumptions. In this article, we apply four different approaches to data from a recent systematic review in the area of nephrology and compare the results. The four approaches use: a linear mixed effects model, a Bayesian multinomial random effects model, a time-to-event model and a nonparametric model, respectively. In the case study data, the accuracy of neutrophil gelatinase-associated lipocalin for the diagnosis of acute kidney injury was assessed in different scenarios, with sensitivity and specificity estimates available for three thresholds in each primary study. All approaches led to plausible and mostly similar summary results. However, we found considerable differences in results for some scenarios, for example, differences in the area under the receiver operating characteristic curve (AUC) of up to 0.13. The Bayesian approach tended to lead to the highest values of the AUC, and the nonparametric approach tended to produce the lowest values across the different scenarios. Though we recommend using these approaches, our findings motivate the need for a simulation study to explore optimal choice of method in various scenarios.

Case-control study on factors associated with a decreased milk yield and a depressed health status of dairy herds in northern Germany

BACKGROUND

In the past years, it became apparent that health status and performance differ considerably within dairy farms in Northern Germany. In order to obtain clues with respect to possible causes of these differences, a case-control study was performed. Case farms, which showed signs of health and performance problems, and control farms, which had none of these signs, were compared. Risk factors from different areas such as health management, housing, hygiene and nutrition were investigated as these are known to be highly influential. The aim of this study was to identify major factors within these areas that have the strongest association with health and performance problems of dairy herds in Northern Germany.

RESULTS

In the final model, a lower energy density in the roughage fraction of the diet, more pens with dirty lying areas and a low ratio of cows per watering spaces were associated with a higher risk for herd health problems. Moreover, case farms were affected by infections with intestinal parasites, lungworms, liver flukes and Johne's Disease numerically more often than control farms. Case farms more often had pens with raised cubicles compared to the deep bedded stalls or straw yards found in control farms. In general, the hygiene of the floors and beddings was worse in case farms. Concerning nutrition, the microbiological and sensory quality of the provided silages was often insufficient, even in control farms. Less roughage was provided to early lactating cows and the feed was pushed to the feeding fence less frequently in case farms than in control farms.

CONCLUSIONS

The results show that milk yield and health status were associated with various factors from different areas stressing the importance of all aspects of management for good animal health and performance. Moreover, this study confirmed well-known risk factors for health problems and performance losses. These should better be taken heed of in herd health management.

Antimicrobial susceptibility testing of Arcobacter butzleri: development and application of a new protocol for broth microdilution

Objectives

To develop a standard reference broth microdilution method for antimicrobial susceptibility testing (AST) of Arcobacter butzleri. The protocol was subsequently applied to a collection of A. butzleri isolates from different sources.

Methods

Broth microdilution susceptibility testing was performed on eight A. butzleri isolates in three media: non-supplemented CAMHB, CAMHB + 2% FBS and CAMHB + 5% FBS. The MIC values were read after 24 and 48 h of incubation at 35 ± 2 °C in ambient air. A logistic regression model was used to determine the combination of medium and incubation time yielding the most homogeneous results. Subsequently, the protocol was applied to 65 A. butzleri isolates to determine their MICs of 31 antimicrobial agents.

Results

The statistical analysis revealed that the most homogeneous MIC values were obtained with CAMHB + 5% FBS and reading of MIC values after 24 h of incubation. The standardized method was successful for AST of all 65 A. butzleri isolates. MIC values were distributed unimodally for most antimicrobial agents. However, one field isolate showed elevated MIC values of gentamicin, streptomycin, tetracycline and trimethoprim/sulfamethoxazole.

Conclusions

This study presents a new protocol for AST of A. butzleri by broth microdilution and shows the distribution of MIC values of 31 antimicrobial agents for a collection of A. butzleri isolates from different origins.

Antibiotic Resistances in Livestock: A Comparative Approach to Identify an Appropriate Regression Model for Count Data

Antimicrobial resistance in livestock is a matter of general concern. To develop hygiene measures and methods for resistance prevention and control, epidemiological studies on a population level are needed to detect factors associated with antimicrobial resistance in livestock holdings. In general, regression models are used to describe these relationships between environmental factors and resistance outcome. Besides the study design, the correlation structures of the different outcomes of antibiotic resistance and structural zero measurements on the resistance outcome as well as on the exposure side are challenges for the epidemiological model building process. The use of appropriate regression models that acknowledge these complexities is essential to assure valid epidemiological interpretations. The aims of this paper are (i) to explain the model building process comparing several competing models for count data (negative binomial model, quasi-Poisson model, zero-inflated model, and hurdle model) and (ii) to compare these models using data from a cross-sectional study on antibiotic resistance in animal husbandry. These goals are essential to evaluate which model is most suitable to identify potential prevention measures. The dataset used as an example in our analyses was generated initially to study the prevalence and associated factors for the appearance of cefotaxime-resistant Escherichia coli in 48 German fattening pig farms. For each farm, the outcome was the count of samples with resistant bacteria. There was almost no overdispersion and only moderate evidence of excess zeros in the data. Our analyses show that it is essential to evaluate regression models in studies analyzing the relationship between environmental factors and antibiotic resistances in livestock. After model comparison based on evaluation of model predictions, Akaike information criterion, and Pearson residuals, here the hurdle model was judged to be the most appropriate model.

The Benefit of Baseline Staging-Risk Assessment of Distant Breast Cancer Metastases by Tumor Stage

BACKGROUND

Despite recommendations of international societies, use of baseline staging in breast cancer varies considerably. We retrospectively analyzed the prevalence of metastases in each pTN stage to estimate the benefit of staging.

PATIENTS AND METHODS

The prevalence of metastases at primary diagnosis (M1) and in the first year after diagnosis (M112) was determined in 2,906 patients.

RESULTS

The prevalence of M1 was 0.95% [95% confidence interval (CI)=0.53-1.70%] in pT1pN0, 2.17% (95% CI=1.00-4.64) in pT1pN1 and 1.53% (95% CI=0.78-2.99%) in pT2pN0. The prevalence of M112 was 2.17% (95% CI=1.47-3.18%) in pT1pN0 and 3.25% in pathological stage IIA (upper confidence bound 5.14%). In pT2pN1 the prevalence of M1 and M112 was 3.49% (95% CI=1.96-6.14%) and 6.35% (95% CI=4.15-9.60%), respectively. Results for stage pT3pN0 and higher were inconclusive.

CONCLUSION

Baseline staging can be safely abandoned in pathological stage I and IIA. Individual decisions should be made for pT2pN1. Staging is recommended in stages of pT3pN0 or higher.

Kinetic therapy in multiple trauma patients with severe blunt chest trauma: an analysis at a level-1 trauma center

BACKGROUND AND OBJECTIVES

Chest trauma is a relevant risk factor for mortality after multiple trauma. Kinetic therapy (KT) represents a potential treatment option in order to restore pulmonary function. Decision criteria for performing kinetic therapy are not fully elucidated. The purpose of this study was to investigate the decision making process to initiate kinetic therapy in a well defined multiple trauma cohort.

METHODS

A retrospective analysis (2000-2009) of polytrauma patients (age > 16 years, ISS ⩾ 16) with severe chest trauma (AIS(Chest) ⩾ 3) was performed. Patients with AIS(Head) ⩾ 3 were excluded. Patients receiving either kinetic (KT+) or lung protective ventilation strategy (KT-) were compared. Chest trauma was classified according to the AIS(Chest), Pulmonary Contusion Score (PCS), Wagner Jamieson Score and Thoracic Trauma Severity Score (TTS). There were multiple outcome parameters investigated included mortality, posttraumatic complications and clinical data. A multivariate regression analysis was performed.

RESULTS

Two hundred and eighty-three patients were included (KT+: n=160; KT-: n=123). AIS(Chest), age and gender were comparable in both groups. There were significant higher values of the ISS, PCS, Wagner Jamieson Score and TTS in group KT+. The incidence of posttraumatic complications and mortality was increased compared to group KT- (p< 0.05). Despite that, kinetic therapy failed to be an independent risk factor for mortality in multivariate logistic regression analysis.

CONCLUSIONS

Kinetic therapy is an option in severely injured patients with severe chest trauma. Decision making is not only based on anatomical aspects such as the AIS(Chest), but on overall injury severity, pulmonary contusions and physiological deterioration. It could be assumed that the increased mortality in patients receiving KT is primarily caused by these factors and does not reflect an independent adverse effect of KT. Furthermore, KT was not shown to be an independent risk factor for mortality.

Recommendation for a Standardised Method of Broth Microdilution Susceptibility Testing for Porcine Bordetella bronchiseptica

The objective was to establish and standardise a broth microdilution susceptibility testing method for porcine Bordetella (B.) bronchiseptica. B. bronchiseptica isolates from different geographical regions and farms were genotyped by macrorestriction analysis and subsequent pulsed-field gel electrophoresis. One reference and one type strain plus two field isolates of B. bronchiseptica were chosen to analyse growth curves in four different media: cation-adjusted Mueller-Hinton broth (CAMHB) with and without 2% lysed horse blood, Brain-Heart-Infusion (BHI), and Caso broth. The growth rate of each test strain in each medium was determined by culture enumeration and the suitability of CAMHB was confirmed by comparative statistical analysis. Thereafter, reference and type strain and eight epidemiologically unrelated field isolates of B. bronchiseptica were used to test the suitability of a broth microdilution susceptibility testing method following CLSI-approved performance standards given in document VET01-A4. Susceptibility tests, using 20 antimicrobial agents, were performed in five replicates, and data were collected after 20 and 24 hours incubation and statistically analysed. Due to the low growth rate of B. bronchiseptica, an incubation time of 24 hours resulted in significantly more homogeneous minimum inhibitory concentrations after five replications compared to a 20-hour incubation. An interlaboratory comparison trial including susceptibility testing of 24 antimicrobial agents revealed a high mean level of reproducibility (97.9%) of the modified method. Hence, in a harmonization for broth microdilution susceptibility testing of B. bronchiseptica, an incubation time of 24 hours in CAMHB medium with an incubation temperature of 35°C and an inoculum concentration of approximately 5 x 10⁵ cfu/ml was proposed.

Effects of ultrafine particles on the allergic inflammation in the lung of asthmatics: results of a double-blinded randomized cross-over clinical pilot study

BACKGROUND

Epidemiological and experimental studies suggest that exposure to ultrafine particles (UFP) might aggravate the allergic inflammation of the lung in asthmatics.

METHODS

We exposed 12 allergic asthmatics in two subgroups in a double-blinded randomized cross-over design, first to freshly generated ultrafine carbon particles (64 μg/m³; 6.1 ± 0.4 × 10⁵ particles/cm³ for 2 h) and then to filtered air or vice versa with a 28-day recovery period in-between. Eighteen hours after each exposure, grass pollen was instilled into a lung lobe via bronchoscopy. Another 24 hours later, inflammatory cells were collected by means of bronchoalveolar lavage (BAL). (

TRIAL REGISTRATION

NCT00527462) RESULTS: For the entire study group, inhalation of UFP by itself had no significant effect on the allergen induced inflammatory response measured with total cell count as compared to exposure with filtered air (p = 0.188). However, the subgroup of subjects, which inhaled UFP during the first exposure, exhibited a significant increase in total BAL cells (p = 0.021), eosinophils (p = 0.031) and monocytes (p = 0.013) after filtered air exposure and subsequent allergen challenge 28 days later. Additionally, the potential of BAL cells to generate oxidant radicals was significantly elevated at that time point. The subgroup that was exposed first to filtered air and 28 days later to UFP did not reveal differences between sessions.

CONCLUSIONS

Our data demonstrate that pre-allergen exposure to UFP had no acute effect on the allergic inflammation. However, the subgroup analysis lead to the speculation that inhaled UFP particles might have a long-term effect on the inflammatory course in asthmatic patients. This should be reconfirmed in further studies with an appropriate study design and sufficient number of subjects.

A multicenter, randomized, open-labeled study to steer immunosuppressive and antiviral therapy by measurement of virus (CMV, ADV, HSV)-specific T cells in addition to determination of trough levels of immunosuppressants in pediatric kidney allograft recipients (IVIST01-trial): study protocol for a randomized controlled trial

BACKGROUND

After kidney transplantation, immunosuppressive therapy causes impaired cellular immune defense leading to an increased risk of viral complications. Trough level monitoring of immunosuppressants is insufficient to estimate the individual intensity of immunosuppression. We have already shown that virus-specific T cells (Tvis) correlate with control of virus replication as well as with the intensity of immunosuppression. The multicentre IVIST01-trial should prove that additional steering of immunosuppressive and antiviral therapy by Tvis levels leads to better graft function by avoidance of over-immunosuppression (for example, viral infections) and drug toxicity (for example, nephrotoxicity).

METHODS/DESIGN

The IVIST-trial starts 4 weeks after transplantation. Sixty-four pediatric kidney recipients are randomized either to a non-intervention group that is only treated conservatively or to an intervention group with additional monitoring by Tvis. The randomization is stratified by centre and cytomegalovirus (CMV) prophylaxis. In both groups the immunosuppressive medication (cyclosporine A and everolimus) is adopted in the same target range of trough levels. In the non-intervention group the immunosuppressive therapy (cyclosporine A and everolimus) is only steered by classical trough level monitoring and the antiviral therapy of a CMV infection is performed according to a standard protocol. In contrast, in the intervention group the dose of immunosuppressants is individually adopted according to Tvis levels as a direct measure of the intensity of immunosuppression in addition to classical trough level monitoring. In case of CMV infection or reactivation the antiviral management is based on the individual CMV-specific immune defense assessed by the CMV-Tvis level. Primary endpoint of the study is the glomerular filtration rate 2 years after transplantation; secondary endpoints are the number and severity of viral infections and the incidence of side effects of immunosuppressive and antiviral drugs.

DISCUSSION

This IVIST01-trial will answer the question whether the new concept of steering immunosuppressive and antiviral therapy by Tvis levels leads to better future graft function. In terms of an effect-related drug monitoring, the study design aims to realize a personalization of immunosuppressive and antiviral management after transplantation. Based on the IVIST01-trial, immunomonitoring by Tvis might be incorporated into routine care after kidney transplantation.

TRIAL REGISTRATION

EudraCT No: 2009-012436-32, ISRCTN89806912 (17 June 2009).

Inflation of the type I error: investigations on regulatory recommendations for bioequivalence of highly variable drugs

PURPOSE

We investigated different evaluation strategies for bioequivalence trials with highly variable drugs on their resulting empirical type I error and empirical power. The classical 'unscaled' crossover design with average bioequivalence evaluation, the Add-on concept of the Japanese guideline, and the current 'scaling' approach of EMA were compared.

METHODS

Simulation studies were performed based on the assumption of a single dose drug administration while changing the underlying intra-individual variability.

RESULTS

Inclusion of Add-on subjects following the Japanese concept led to slight increases of the empirical α-error (≈7.5%). For the approach of EMA we noted an unexpected tremendous increase of the rejection rate at a geometric mean ratio of 1.25. Moreover, we detected error rates slightly above the pre-set limit of 5% even at the proposed 'scaled' bioequivalence limits.

CONCLUSIONS

With the classical 'unscaled' approach and the Japanese guideline concept the goal of reduced subject numbers in bioequivalence trials of HVDs cannot be achieved. On the other hand, widening the acceptance range comes at the price that quite a number of products will be accepted bioequivalent that had not been accepted in the past. A two-stage design with control of the global α therefore seems the better alternative.

Effects of accidental hypothermia on posttraumatic complications and outcome in multiple trauma patients

INTRODUCTION

Accidental hypothermia seems to predispose multiple trauma patients to the development of posttraumatic complications, such as Systemic Inflammatory Response Syndrome (SIRS), sepsis, Multiple Organ Dysfunction Syndrome (MODS), and increased mortality. However, the role of accidental hypothermia as an independent prognostic factor is controversially discussed. The aim of the present study was to evaluate the incidence of accidental hypothermia in multiple trauma patients and its effects on the development of posttraumatic complications and mortality.

PATIENTS AND METHODS

Inclusion criteria for patients in this retrospective study (2005-2009) were an Injury Severity Score (ISS) ≥16, age ≥16 years, admission to our Level I trauma centre within 6h after the accident. Accidental hypothermia was defined as body temperature less than 35°C measured within 2 h after admission, but always before first surgical procedure in the operation theatre. The association between accidental hypothermia and the development of posttraumatic complications as well as mortality was investigated. Statistical analysis was performed with χ(2)-test, Student's t-test, ANOVA and logistic regression. Statistical significance was considered at p<0.05.

RESULTS

310 multiple trauma patients were enrolled in the present study. Patients' mean age was 41.9 (SD 17.5) years, the mean injury severity score was 29.7 (SD 10.2). The overall incidence of accidental hypothermia was 36.8%. The overall incidence of posttraumatic complications was 77.4% (SIRS), 42.9% (sepsis) and 7.4% (MODS), respectively. No association was shown between accidental hypothermia and the development of posttraumatic complications. Overall, 8.7% died during the posttraumatic course. Despite an increased mortality rate in hypothermic patients, hypothermia failed to be an independent risk factor for mortality in multivariate analysis.

CONCLUSIONS

Accidental hypothermia is very common in multiply injured patients. However, it could be assumed that the increase of mortality in hypothermic patients is primarily caused by the injury severity and does not reflect an independent adverse effect of hypothermia. Furthermore, hypothermia was not shown to be an independent risk factor for posttraumatic complications.

Tip apex distance, hip screw placement, and neck shaft angle as potential risk factors for cut-out failure of hip screws after surgical treatment of intertrochanteric fractures

PURPOSE

To describe the quality of osteosynthesis after intertrochanteric fractures evaluation of tip apex distance (TAD) and position of the hip screw have been established. Furthermore, a slightly valgus fracture reduction has been suggested to reduce the risk of cut-out failure. However, uniform recommendations for optimal screw positioning and fracture reduction are still missing. The purpose of our study was to confirm potential risk factors for cut-out of hip screws of intertrochanteric fractures and to provide recommendations for practical clinical use.

METHODS

A retrospective analysis of all patients with intertrochanteric fractures treated with a DHS or a gamma nail between January of 2007 and May of 2010 was performed at a level I trauma center.

RESULTS

Two hundred thirty-five patients with intertrochanteric fractures after intra- and extramedullary stabilization were analyzed. A TAD of more than 25 mm was demonstrated to be the most important factor for cut-out in stable and unstable fractures. Fracture reduction with a valgus NSA of 5-10° was associated with a trend towards a lower rate of screw cut-out while an anterior placement of the screw (Parker's ratio index of <40) significantly increased cut-out incidence.

CONCLUSIONS

According to our results, the TAD should not exceed 25 mm in stable (AO/OTA A1) as well as unstable (AO/OTA A2) fractures. An increased anterior hip screw placement should be avoided while fracture reduction with a slight valgus Neck Shaft seems favorable.

Comparison of different thoracic trauma scoring systems in regards to prediction of post-traumatic complications and outcome in blunt chest trauma

BACKGROUND

As accurate assessment of thoracic injury severity in the early phase after trauma is difficult, we compared different thoracic trauma scores regarding their predictive ability for the development of post-traumatic complications and mortality.

MATERIALS AND METHODS

Two hundred seventy-eight multiple trauma patients (ISS ≥ 16) age > 16 y with severe blunt chest trauma (AIS(chest) ≥ 3) admitted between 2000 and 2009 to Level I Trauma center were included. Exclusion criteria were severe traumatic brain injury (AIS(head) ≥ 3) and penetrating thoracic trauma. The association between AIS(chest), Pulmonary Contusion score (PCS), Wagner-score and Thoracic Trauma Severity score (TTS), and duration of ventilation, length of ICU stay, development of post-traumatic complications, and mortality was investigated. Statistical analysis was performed with χ(2)-test, ANOVA, logistic regression, and receiver operating characteristic (ROC) curve.

RESULTS

Patients' mean age was 42.7 ± 17.0 y, the mean injury severity score was 28.7 ± 9.3 points. Overall, 60 patients (21.6%) developed ARDS, 143 patients (51.4%) SIRS, 110 patients (39.6%) sepsis, and 36 patients (13.0%) MODS. Twenty-two patients (7.9%) died. Among the examined thoracic trauma scores only the TTS was an independent predictor of mortality. With the TTS showing the best prediction power, the TTS, PCS, and Wagner-score were independent predictors of ventilation time, length of ICU stay, and the development of post-traumatic ARDS and MODS.

CONCLUSIONS

Thoracic trauma scores combining anatomical and physiologic parameters like the TTS seem to be most suitable for severity assessment and prediction of outcome in multiple trauma patients with concomitant blunt chest trauma.

Thyroid remnant dose: 124I-PET/CT dosimetric comparison of rhTSH versus thyroid hormone withholding before radioiodine remnant ablation in differentiated thyroid cancer

AIM

Recombinant human thyroid-stimulating hormone (rhTSH) recently was approved as an alternative to thyroid hormone withholding (THW) to elevate TSH for thyroid remnant ablation in differentiated thyroid carcinoma patients. High ablation success rates are reported with diverse rhTSH-aided (131)I activities. Improved renal function causes approximately 50% faster radioiodine clearance under euthyroidism versus hypothyroidism. Knowledge of comparative remnant radioiodine kinetics, particularly the remnant radiation dose in Gy/GBq of administered (131)I activity (RDpA), could assist in choosing rhTSH-aided ablative activities.

MATERIAL AND METHODS

To compare the RDpA, determined through (124)I-positron emission tomography/computed tomography (PET/CT), under the two stimulation methods, we retrospectively divided into two groups 55 consecutive totally-thyroidectomized, radioiodine-naïve patients. The rhTSH group (n=16) received (124)I on thyroid hormone, 24 h after two consecutive daily intramuscular injections of rhTSH, 0.9 mg. The THW group (n=39) received (124)I after weeks-long THW, when serum TSH first measured > or = 25 mIU/L. We performed PET investigations 4 h, 24 h, 48 h, 72 h and 96 h and PET/CT 25 h after (124)I administration.

RESULTS

Median stimulated serum thyroglobulin was 15 times higher (p=0.023) and M1 disease almost twice as prevalent (p=0.05) in rhTSH versus THW patients. Mean+/-standard deviation RDpA was statistically equivalent between the groups: rhTSH, 461+/-600 Gy/GBq, THW, 302+/-329 Gy/GBq, two-sided p=0.258.

CONCLUSIONS

rhTSH or THW deliver statistically equivalent radiation doses to thyroid remnant and may be chosen based on safety, quality-of-life, convenience and pharmacoeconomic factors. Institutional fixed radioiodine activities formulated for use with THW need not be adjusted for rhTSH-aided ablation.

Nonparametric relevance-shifted multiple testing procedures for the analysis of high-dimensional multivariate data with small sample sizes

Background

In many research areas it is necessary to find differences between treatment groups with several variables. For example, studies of microarray data seek to find a significant difference in location parameters from zero or one for ratios thereof for each variable. However, in some studies a significant deviation of the difference in locations from zero (or 1 in terms of the ratio) is biologically meaningless. A relevant difference or ratio is sought in such cases.

Results

This article addresses the use of relevance-shifted tests on ratios for a multivariate parallel two-sample group design. Two empirical procedures are proposed which embed the relevance-shifted test on ratios. As both procedures test a hypothesis for each variable, the resulting multiple testing problem has to be considered. Hence, the procedures include a multiplicity correction. Both procedures are extensions of available procedures for point null hypotheses achieving exact control of the familywise error rate. Whereas the shift of the null hypothesis alone would give straight-forward solutions, the problems that are the reason for the empirical considerations discussed here arise by the fact that the shift is considered in both directions and the whole parameter space in between these two limits has to be accepted as null hypothesis.

Conclusion

The first algorithm to be discussed uses a permutation algorithm, and is appropriate for designs with a moderately large number of observations. However, many experiments have limited sample sizes. Then the second procedure might be more appropriate, where multiplicity is corrected according to a concept of data-driven order of hypotheses.