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Background Acute appendicitis (AA) is the most common surgical disease, and appendectomy is the treatment of choice in the majority of cases. A correct diagnosis is key for decreasing the negative appendectomy rate. The management can become difficult in case of complicated appendicitis. The aim of this study is to describe the worldwide clinical and diagnostic work-up and management of AA in surgical departments. Methods This prospective multicenter observational study was performed in 116 worldwide surgical departments from 44 countries over a 6-month period (April 1, 2016–September 30, 2016). All consecutive patients admitted to surgical departments with a clinical diagnosis of AA were included in the study. Results A total of 4282 patients were enrolled in the POSAW study, 1928 (45%) women and 2354 (55%) men, with a median age of 29 years. Nine hundred and seven (21.2%) patients underwent an abdominal CT scan, 1856 (43.3%) patients an US, and 285 (6.7%) patients both CT scan and US. A total of 4097 (95.7%) patients underwent surgery; 1809 (42.2%) underwent open appendectomy and 2215 (51.7%) had laparoscopic appendectomy. One hundred eighty-five (4.3%) patients were managed conservatively. Major complications occurred in 199 patients (4.6%). The overall mortality rate was 0.28%. Conclusions The results of the present study confirm the clinical value of imaging techniques and prognostic scores. Appendectomy remains the most effective treatment of acute appendicitis. Mortality rate is low.

In the present article, we propose a Jackknife empirical likelihood (JEL) ratio test for testing the independence of time to failure and cause of failure in competing risks data. We use the U-statistics theory to derive the JEL ratio test. The asymptotic distribution of the test statistic is shown to be the standard chi-square distribution. A Monte Carlo simulation study is carried out to assess the finite sample behavior of the proposed test. The performance of the proposed JEL test is compared with the test given by Dewan et al. (2004). Finally, we illustrate our test procedure using two real data sets.

This research is motivated by one of our survey studies to assess the potential influence of introducing zebra mussels to the Lake Mead National Recreation Area, Nevada. One research question in this study is to investigate the association between the boating activity type and the awareness of zebra mussels. A chi-squared test is often used for testing independence between two factors with nominal levels. When the null hypothesis of independence between two factors is rejected, we are often left wondering where does the significance come from. Cell residuals, including standardized residuals and adjusted residuals, are traditionally used in testing for cell significance, which is often known as a post hoc test after a statistically significant chi-squared test. In practice, the limiting distributions of these residuals are utilized for statistical inference. However, they may lead to different conclusions based on the calculated p-values, and their p-values could be over- o6r under-estimated due to the unsatisfactory performance of asymptotic approaches with regards to type I error control. In this article, we propose new exact p-values by using Fisher's approach based on three commonly used test statistics to order the sample space. We theoretically prove that the proposed new exact p-values based on these test statistics are the same. Based on our extensive simulation studies, we show that the existing asymptotic approach based on adjusted residual is often more likely to reject the null hypothesis as compared to the exact approach due to the inflated family-wise error rates as observed. We would recommend the proposed exact p-value for use in practice as a valuable post hoc analysis technique for chi-squared analysis.

An epidemiologic study that used large cancer databases (National Cancer Database and SEER) showed that minimally invasive hysterectomy was associated with shorter survival than laparotomy among patients with early cervical cancer. A prospective randomized trial and an epidemiologic study that used large cancer databases (National Cancer Database and SEER) both showed that minimally invasive radical hysterectomy was associated with shorter survival in early cervical cancer than open abdominal radical hysterectomy.

Background Valid and reliable instruments for the measurement of enacted, anticipated and internalised stigma in people living with HIV are crucial for mapping trends in the prevalence of HIV-related stigma and tracking the effectiveness of stigma-reducing interventions. Although longer instruments exist, e.g., the commonly used 40-item HIV Stigma Scale by Berger et al., a shorter instrument would be preferable to facilitate the inclusion of HIV stigma in more and broader surveys. Therefore, the aim of this work was to develop a substantially shorter, but still valid, version of the HIV Stigma Scale. Methods Data from a psychometric evaluation of the Swedish 40-item HIV Stigma Scale were reanalysed to create a short version with 12 items (three from each of the four stigma subscales: personalised stigma , disclosure concerns , concerns with public attitudes and negative self-image ). The short version of the HIV stigma scale was then psychometrically tested using data from a national survey investigating stigma and quality of life among people living with HIV in Sweden ( n  = 880, mean age 47.9 years, 26% female). Results The hypothesized factor structure of the proposed short version was replicated in exploratory factor analysis without cross loadings and confirmatory factor analysis supported construct validity with high standardised effects (>0.7) of items on the intended scales. The χ 2 test was statistically significant (χ 2  = 154.2, df = 48, p  < 0.001), but alternate fit measures indicated acceptable fit (comparative fit index: 0.963, Tucker-Lewis index: 0.950 and root mean square error of approximation: 0.071). Corrected item-total correlation coefficients were >0.4 for all items, with a variation indicating that the broadness of the concept of stigma had been captured. All but two aspects of HIV-related stigma that the instrument is intended to cover were captured by the selected items in the short version. The aspects that did not lose any items were judged to have acceptable psychometric properties. The short version of the instrument showed higher floor and ceiling effects than the full-length scale, indicating a loss of sensitivity in the short version. Cronbach’s α for the subscales were all >0.7. Conclusions Although being less sensitive in measurement, the proposed 12-item short version of the HIV Stigma Scale has comparable psychometric properties to the full-length scale and may be used when a shorter instrument is needed.

A scaled difference test statistic that can be computed from standard software of structural equation models (SEM) by hand calculations was proposed in Satorra and Bentler (Psychometrika 66:507–514, 2001 ). The statistic is asymptotically equivalent to the scaled difference test statistic introduced in Satorra (Innovations in Multivariate Statistical Analysis: A Festschrift for Heinz Neudecker, pp. 233–247, 2000 ), which requires more involved computations beyond standard output of SEM software. The test statistic has been widely used in practice, but in some applications it is negative due to negativity of its associated scaling correction. Using the implicit function theorem, this note develops an improved scaling correction leading to a new scaled difference statistic that avoids negative chi-square values.

In three phase 3 trials involving patients with ulcerative colitis, tofacitinib (an oral, small-molecule Janus kinase inhibitor) was more effective as induction and maintenance therapy than placebo. Infections were more common with tofacitinib. Ulcerative colitis is characterized by an increased frequency of bowel movements and bloody diarrhea, which has a negative effect on quality of life. 1 Current therapies for ulcerative colitis include mesalamine, glucocorticoids, thiopurines, and antagonists to tumor necrosis factor (TNF) and α4β7 integrin. 1 – 5 Many patients do not have a response to these therapies or have a response that is not sustained. Additional treatment options with new mechanisms of action are needed to increase efficacy rates. The Janus kinase (JAK) family comprises four intracellular tyrosine kinases — JAK1, JAK2, JAK3, and nonreceptor tyrosine-protein kinase 2 — that activate signal transducers and . . .

Children 4 to 11 months of age who were at high risk for development of peanut allergy were assigned to consumption or avoidance of peanuts until 60 months of age. Peanut allergy was more than five times as likely to develop in children assigned to peanut avoidance. The prevalence of peanut allergy among children in Western countries has doubled in the past 10 years, reaching rates of 1.4 to 3.0%, 1 – 3 and peanut allergy is becoming apparent in Africa and Asia. 4 , 5 This allergy is the leading cause of anaphylaxis and death due to food allergy and imposes substantial psychosocial and economic burdens on patients and their families. 6 Peanut allergy develops early in life and is rarely outgrown. 7 – 9 Clinical practice guidelines from the United Kingdom in 1998 9 and from the United States in 2000 10 recommended the exclusion of allergenic foods from the diets of infants at . . .

To evaluate model fit in confirmatory factor analysis, researchers compare goodness-of-fit indices (GOFs) against fixed cutoff values (e.g., CFI > .950) derived from simulation studies. Methodologists have cautioned that cutoffs for GOFs are only valid for settings similar to the simulation scenarios from which cutoffs originated. Despite these warnings, fixed cutoffs for popular GOFs (i.e., χ 2 , χ 2 / df , CFI, RMSEA, SRMR) continue to be widely used in applied research. We (1) argue that the practice of using fixed cutoffs needs to be abandoned and (2) review time-honored and emerging alternatives to fixed cutoffs. We first present the most in-depth simulation study to date on the sensitivity of GOFs to model misspecification (i.e., misspecified factor dimensionality and unmodeled cross-loadings) and their susceptibility to further data and analysis characteristics (i.e., estimator, number of indicators, number and distribution of response options, loading magnitude, sample size, and factor correlation). We included all characteristics identified as influential in previous studies. Our simulation enabled us to replicate well-known influences on GOFs and establish hitherto unknown or underappreciated ones. In particular, the magnitude of the factor correlation turned out to moderate the effects of several characteristics on GOFs. Second, to address these problems, we discuss several strategies for assessing model fit that take the dependency of GOFs on the modeling context into account. We highlight tailored (or “dynamic”) cutoffs as a way forward. We provide convenient tables with scenario-specific cutoffs as well as regression formulae to predict cutoffs tailored to the empirical setting of interest.

Central centrifugal cicatricial alopecia is a common form of scarring alopecia in women of African ancestry. This study uncovered a genetic susceptibility in approximately one third of the women studied: loss-of-function variants affecting the enzyme PADI3, which modifies proteins involved in hair growth.