Definition of clinically relevant intraoperative hypotension: A data-driven approach.

Background: Associations between intraoperative hypotension (IOH) and various postoperative outcomes were shown in retrospective trials using a variety of different definitions of IOH. This complicates the comparability of these trials and makes clinical application difficult. Information about the best performing definitions of IOH regarding 30-day mortality, hospital length of stay (hLOS), and postanesthesia care unit length of stay (PACU-LOS) is missing.

Sex differences in the survival benefit of kidney transplantation: a retrospective cohort study using target trial emulation.

Background: Kidney transplantation is the preferred treatment for eligible patients with kidney failure who need renal replacement therapy. However, it remains unclear whether the anticipated survival benefit from kidney transplantation is different for women and men.

Methods: We included all dialysis patients recorded in the Austrian Dialysis and Transplant Registry who were waitlisted for their first kidney transplant between 2000 and 2018.

Leave-one-out cross-validation, penalization, and differential bias of some prediction model performance measures-a simulation study.

Background: The performance of models for binary outcomes can be described by measures such as the concordance statistic (c-statistic, area under the curve), the discrimination slope, or the Brier score. At internal validation, data resampling techniques, e.g.

Intraoperative Hypotension Is Associated with Postoperative Nausea and Vomiting in the PACU: A Retrospective Database Analysis.

Multiple risk factors for postoperative nausea and vomiting (PONV)-a very distressing and outcome-related complication-have been identified, including female sex, absence of a history of smoking, history of PONV, and postoperative opioid use. Evidence of association of intraoperative hypotension with PONV is contradictory. A retrospective analysis of the perioperative documentation of 38,577 surgeries was conducted.

The value of intraoperative parathyroid hormone monitoring in patients with primary hyperparathyroidism and varying baseline parathyroid hormone levels.

Background: When applying intraoperative parathyroid hormone monitoring (IOPTH) to patients with primary hyperparathyroidism (PHPT), there are established criteria predicting biochemical cure in patients with basal parathyroid hormone (PTH) levels in the medium range (100-400 pg/ml); however, there is a challenge concerning patients with low (less than 100 pg/ml) or high (more than 400 pg/ml) basal PTH levels. The aim of this study was to investigate the value of the 'Vienna criterion' applied during IOPTH in patients with PHPT and various basal PTH concentrations.

Methods: Consecutive patients between 1999-2009 with a biochemical diagnosis of PHPT who underwent surgical parathyroidectomy were included.

Survival Benefit of First Single-Organ Deceased Donor Kidney Transplantation Compared With Long-term Dialysis Across Ages in Transplant-Eligible Patients With Kidney Failure.

Importance: Kidney transplant is considered beneficial in terms of survival compared with continued dialysis for patients with kidney failure. However, randomized clinical trials are infeasible, and available evidence from cohort studies is at high risk of bias.

Objective: To compare restricted mean survival times (RMSTs) between patients who underwent transplant and patients continuing dialysis across transplant candidate ages and depending on waiting time, applying target trial emulation methods.

An investigation of penalization and data augmentation to improve convergence of generalized estimating equations for clustered binary outcomes.

Background: In binary logistic regression data are 'separable' if there exists a linear combination of explanatory variables which perfectly predicts the observed outcome, leading to non-existence of some of the maximum likelihood coefficient estimates. A popular solution to obtain finite estimates even with separable data is Firth's logistic regression (FL), which was originally proposed to reduce the bias in coefficient estimates. The question of convergence becomes more involved when analyzing clustered data as frequently encountered in clinical research, e.

Solutions to problems of nonexistence of parameter estimates and sparse data bias in Poisson regression.

Poisson regression can be challenging with sparse data, in particular with certain data constellations where maximum likelihood estimates of regression coefficients do not exist. This paper provides a comprehensive evaluation of methods that give finite regression coefficients when maximum likelihood estimates do not exist, including Firth's general approach to bias reduction, exact conditional Poisson regression, and a Bayesian estimator using weakly informative priors that can be obtained via data augmentation. Furthermore, we include in our evaluation a new proposal for a modification of Firth's approach, improving its performance for predictions without compromising its attractive bias-correcting properties for regression coefficients.

On transfer homomorphisms of Krull monoids.

Every Krull monoid has a transfer homomorphism onto a monoid of zero-sum sequences over a subset of its class group. This transfer homomorphism is a crucial tool for studying the arithmetic of Krull monoids. In the present paper, we strengthen and refine this tool for Krull monoids with finitely generated class group.

Retrospective, Multicenter Analysis Comparing Conventional with Oncoplastic Breast Conserving Surgery: Oncological and Surgical Outcomes in Women with High-Risk Breast Cancer from the OPBC-01/iTOP2 Study.

Introduction: Recent data suggest that margins ≥2 mm after breast-conserving surgery may improve local control in invasive breast cancer (BC). By allowing large resection volumes, oncoplastic breast-conserving surgery (OBCII; Clough level II/Tübingen 5-6) may achieve better local control than conventional breast conserving surgery (BCS; Tübingen 1-2) or oncoplastic breast conservation with low resection volumes (OBCI; Clough level I/Tübingen 3-4).

Methods: Data from consecutive high-risk BC patients treated in 15 centers from the Oncoplastic Breast Consortium (OPBC) network, between January 2010 and December 2013, were retrospectively reviewed.

To tune or not to tune, a case study of ridge logistic regression in small or sparse datasets.

Background: For finite samples with binary outcomes penalized logistic regression such as ridge logistic regression has the potential of achieving smaller mean squared errors (MSE) of coefficients and predictions than maximum likelihood estimation. There is evidence, however, that ridge logistic regression can result in highly variable calibration slopes in small or sparse data situations.

Methods: In this paper, we elaborate this issue further by performing a comprehensive simulation study, investigating the performance of ridge logistic regression in terms of coefficients and predictions and comparing it to Firth's correction that has been shown to perform well in low-dimensional settings.

Biomarker-based early detection of epithelial ovarian cancer based on a five-protein signature in patient's plasma - a prospective trial.

Background: Trial on five plasma biomarkers (CA125, HE4, OPN, leptin, prolactin) and their possible role in differentiating benign from malignant ovarian tumors.

Methods: In this unicentric prospective trial preoperative blood samples of 43 women with ovarian masses determined for ovarian surgery were analyzed. 25 patients had pathologically confirmed benign, 18 malignant ovarian tumors.

Steroid pretreatment of deceased donors and liver allograft function - Ten years follow-up of a blinded randomized placebo controlled trial.

Background: Within the last decade numerous attempts have been reported in order to expand the donor pool and alleviate organ shortage in the setting of liver transplantation. Aim of this blinded randomized controlled trial was to evaluate the effect of donor steroid pretreatment on outcomes after liver transplantation.

Methods: We performed an international, multi-center double-blinded randomized placebo controlled trial.

On the arithmetic of stable domains.

A commutative ring is stable if every non-zero ideal of is projective over its ring of endomorphisms. Motivated by a paper of Bass in the 1960s, stable rings have received wide attention in the literature ever since then. Much is known on the algebraic structure of stable rings and on the relationship of stability with other algebraic properties such as divisoriality and the 2-generator property.

The spectrum of skin diseases in four different types of organ-transplant recipients: a comparative single-centre cohort study.

Background: Organ transplant recipients (OTR) are at marked increased risk of skin cancer and skin infections compared to the general population.

Objectives: The purpose of this study was to acquire long-term incidence data on commonly occurring skin diseases in four different transplant groups.

Materials & Methods: This retrospective single-centre cohort study included 621 OTR.

On strongly primary monoids and domains.

A commutative integral domain is primary if and only if it is one-dimensional and local. A domain is strongly primary if and only if it is local and each nonzero principal ideal contains a power of the maximal ideal. Hence, one-dimensional local Mori domains are strongly primary.

Bring More Data!-A Good Advice? Removing Separation in Logistic Regression by Increasing Sample Size.

The parameters of logistic regression models are usually obtained by the method of maximum likelihood (ML). However, in analyses of small data sets or data sets with unbalanced outcomes or exposures, ML parameter estimates may not exist. This situation has been termed 'separation' as the two outcome groups are separated by the values of a covariate or a linear combination of covariates.

A characterization of seminormal C-monoids.

It is well-known that a C-monoid is completely integrally closed if and only if its reduced class semigroup is a group and if this holds, then the C-monoid is a Krull monoid and the reduced class semigroup coincides with the usual class group of Krull monoids. We prove that a C-monoid is seminormal if and only if its reduced class semigroup is a union of groups. Based on this characterization we establish a criterion (in terms of the class semigroup) when seminormal C-monoids are half-factorial.

Applicability of a shortened interpretation model for intraoperative parathyroid hormone monitoring in patients with primary hyperparathyroidism in an endemic goiter region.

Background: In primary hyperparathyroidism (pHPT), quick intraoperative parathyroid hormone monitoring (IOPTH) is performed to predict complete excision of hyperfunctioning tissue and therefore cure. In recent years, efforts have been made to make this prediction more accurate and to shorten the duration of the test, respectively, and therefore reduce waiting and total operating time. The aim of this study was to evaluate the practicability and safety of a time-reduced criterion (decline ≥ 35% after 5 min) in a large cohort of patients.

Mortality and continuity of care - Definitions matter! A cohort study in diabetics.

Objective: To demonstrate that when investigating the relevance of continuity of care for patient outcomes, different definitions can lead to contradicting results.

Methods: We used claims data from the regional public health insurer of Lower Austria covering the period from 2008 to 2011. The study sample included subjects with repeated dispensings of anti-diabetic drugs.

Fumaric acid esters in combination with a 6-week course of narrowband ultraviolet B provides an accelerated response compared with fumaric acid esters monotherapy in patients with moderate-to-severe plaque psoriasis: a randomized prospective clinical study.

Background: Fumaric acid esters (FAE) are safe and effective in patients with moderate-to-severe psoriasis but have a slow onset of action. A short-term combination with narrowband ultraviolet B (NB-UVB) may substantially accelerate the therapeutic response in the induction phase of treatment.

Objectives: To assess the synergistic effect of a 6-week course of NB-UVB phototherapy in addition to FAE in adults with moderate-to-severe plaque psoriasis.

Separation in Logistic Regression: Causes, Consequences, and Control.

Separation is encountered in regression models with a discrete outcome (such as logistic regression) where the covariates perfectly predict the outcome. It is most frequent under the same conditions that lead to small-sample and sparse-data bias, such as presence of a rare outcome, rare exposures, highly correlated covariates, or covariates with strong effects. In theory, separation will produce infinite estimates for some coefficients.

A Complex Network of Tumor Microenvironment in Human High-Grade Serous Ovarian Cancer.

Most high-grade serous ovarian cancer (HGSOC) patients develop recurrent disease after first-line treatment, frequently with fatal outcome. This work aims at studying the molecular biology of both primary and recurrent HGSOC. Gene expression profiles of matched primary and recurrent fresh-frozen tumor tissues from 66 HGSOC patients were obtained by RNA sequencing.

Primary hyperparathyroidism: Dynamic postoperative metabolic changes.

Objective: Little is known about the natural changes in parathyroid function after successful parathyroid surgery for primary hyperparathyroidism. The association of intact parathyroid hormone (iPTH) and calcium (Ca) with "temporary hypoparathyroidism" and "hungry bone syndrome" (HBS) was evaluated.

Design: Potential risk factors for temporary hypoparathyroidism and HBS were evaluated by taking blood samples before surgery, intra-operatively, at postoperative day (POD) 1, at POD 5 to 7, in postoperative week (POW) 8 and in postoperative month (POM) 6.