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Aims: It is important to assess sleep quality during epidemiological surveillance of psychological and physical health among nonclinical adolescents. The Pittsburgh Sleep Quality Index (PSQI) is a self-report screening tool that measures sleep quality. This study aimed to assess the validity and reliability of the Chinese version of the PSQI among nonclinical adolescents. Methods: In total, 5,399 Chinese students (51.1% female) were included in the study (mean age = 15.13, SD = 1.56). Participants completed a comprehensive questionnaire including the PSQI. Statistical analyses to evaluate the reliability, structural validity, measurement invariance, criterion validity and optimal cutoff point of the PSQI were performed. Results: The internal consistency of the PSQI was moderate. Confirmatory factor analysis supported the three-dimensional model and the configural and metric invariance across gender and age. The correlations between scores on the PSQI and the Minneapolis-Manchester Quality of Life Instrument (as a measure of positive life aspects) as well as between scores on the PSQI and the Hospital Anxiety Depression Scale (as a measure of mental illness and distress) yielded support for criterion validity. The receiver operating characteristic analysis revealed that a score of 6.5 was the optimal cutoff point for the PSQI to diagnose sleep disturbance. Conclusion: The main findings of this study are consistent with many studies from other countries that evaluated the psychometric properties of the PSQI and support the use of this instrument in assessing sleep quality in Chinese nonclinical adolescents. Future studies should continue to verify the ability to monitor sleep quality across the lifespan using the PSQI. [ABSTRACT FROM AUTHOR]

Purpose: Meaningful thresholds are needed to interpret patient-reported outcome measure (PROM) results. This paper introduces a new method, based on item response theory (IRT), to estimate such thresholds. The performance of the method is examined in simulated datasets and two real datasets, and compared with other methods. Methods: The IRT method involves fitting an IRT model to the PROM items and an anchor item indicating the criterion state of interest. The difficulty parameter of the anchor item represents the meaningful threshold on the latent trait. The latent threshold is then linked to the corresponding expected PROM score. We simulated 4500 item response datasets to a 10-item PROM, and an anchor item. The datasets varied with respect to the mean and standard deviation of the latent trait, and the reliability of the anchor item. The real datasets consisted of a depression scale with a clinical depression diagnosis as anchor variable and a pain scale with a patient acceptable symptom state (PASS) question as anchor variable. Results: The new IRT method recovered the true thresholds accurately across the simulated datasets. The other methods, except one, produced biased threshold estimates if the state prevalence was smaller or greater than 0.5. The adjusted predictive modeling method matched the new IRT method (also in the real datasets) but showed some residual bias if the prevalence was smaller than 0.3 or greater than 0.7. Conclusions: The new IRT method perfectly recovers meaningful (interpretational) thresholds for multi-item questionnaires, provided that the data satisfy the assumptions for IRT analysis. [ABSTRACT FROM AUTHOR]

The optimum cutoff point for a diagnostic test is the point along the ROC curve where the test performs best (has the best sensitivity and specificity available for that test). Keywords: ROC curve; receiver operating curve; statistics; cutoff point EN ROC curve receiver operating curve statistics cutoff point 163 167 5 03/24/22 20220401 NES 220401 In toxicology, we are often concerned with determining "cutoff points." The point of maximum sensitivity and specificity (the optimum cutoff point for a test), usually in the top upper left of the ROC curve, is identified using the Youden Index calculation. Consequently, both of these studies used ROC curves to obtain optimum cutoff points to help risk stratify patients for the development of clinically significant toxicity following a drug overdose. [Extracted from the article]

Purpose: No standardized execution or evidence demonstrates the area of the digit giving the most accurate capillary refill time (CRT). This study investigated the reliability and validity of CRT, and the relative merits of areas where the test could be performed. Methods: In all, 127 healthy volunteers were assessed for normal CRT at the fingernail, lateral paronychia, and proximal and distal pulps of the index finger. The predictive validity of the CRT for the diagnosis of compromised vascular perfusion was also investigated on 24 subjects, using an inflated tourniquet. Three raters assessed interobserver reliability. Results: The mean fingernail, lateral paronychia, proximal pulp, and distal pulp CRTs were 1.93, 1.78, 1.70, and 1.57 s, respectively. The tourniquet and non-tourniquet results demonstrated significant mean differences; however, the fingernail showed a subtle difference (1.22 s) compared with the proximal pulp (4.46 s). The CRT interobserver reliability was fair at the fingernail (intraclass correlation coefficient [ICC] = 0.51), but very poor in occluded limbs (ICC = 0.13). At the lateral paronychia and finger pulp, the interobserver reliability was reasonable (ICC = 0.75–0.81 [non-tourniquet] vs 0.62–0.68 [tourniquet]). In a receiver-operating characteristic curve analysis, the proximal pulp demonstrated better discrimination (area under the curve = 0.93, 95% CI 0.89–0.97, p < 0.0001); the best cutoff point was calculated to be 3 s at the proximal pulp. Conclusions: CRT use at appropriate areas is reliable. The most dependable site is the finger pulp, and the proposed cutoff is 3 s. [ABSTRACT FROM AUTHOR]

Purpose: Histological confirmation of endometrial cancer by dilatation/curettage (D/C) in women with postmenopausal bleeding (PMB) can be challenging due to anesthesiological and/or surgical risks. Thus, less invasive methods for diagnostics are required to identify patients with minimal risk for endometrial cancer (EC) to avoid unnecessary surgical intervention. The objective of this single-center cohort study was to assess the diagnostic validity of transvaginal ultrasound (TVUS) measurements of endometrial thickness (ET) in patients with PMB for the detection of EC.Methods: A retrospective analysis of data from patients presenting between January 2005 and August 2014 at the Department of Obstetrics and Gynecology, University Hospital Ulm, Germany, with PMB and subsequent D/C was performed. Complete data with TVUS documentation of ET and histological results of tissue samples were available from 254 patients. In addition, data on age, body mass index (BMI), ASA-score, diabetes, hypertension, and hematological laboratory values (for a smaller subsample) were recorded. To identify independent risk factors, a multivariate logistic regression with endometrial cancer as binary response variable (yes/no) was performed. Diagnostic efficacy data for different ET cutoff points (≤1 to ≤26 mm) were obtained by a receiver operator characteristic (ROC) curve analysis.Results: The multivariate logistic regression revealed a significant independent predictive value for age and ET. However, none of the analyzed ET cutoff points showed optimal diagnostic validity, as all cutoff points with sensitivity rates above 90% (≤1 to ≤5 mm) had false positive rates of 70% and higher.Conclusions: There is no ET cutoff point that provides good diagnostic accuracy and/or reliably excludes the presence of endometrial cancer in patients with PMB. Thus, our data analysis supports the actual German approach of histological evaluation of any PMB to confirm or exclude EC. [ABSTRACT FROM AUTHOR]

The aim of this investigation is to examine the correlation between the HbA1c numbers used by the National Glycohemoglobin Standardization Program (NGSP) and the Japan Diabetes Society (JDS) and to validate the HbA1c cutoff values of 6.5 and 6.1 % set for the diagnosis of diabetes mellitus by the American Diabetes Association (ADA) and the JDS, respectively. NGSP HbA1c values obtained from the monthly monitoring program of the performance of the NGSP Secondary Reference Laboratories (SRLs) were provided by the NGSP. The samples used in the NGSP monitoring program were also assayed to obtain the JDS values at the Laboratory of Reference Material Institute for Clinical Chemistry Standards (ReCCS) using the KO 500 designated comparison method (DCM) calibrated with a reference material, JDS Lot 4, issued by ReCCS. The results were compared, and the correlation between the two data sets was examined by linear regression. The relationship between the NGSP SRLs values and JDS values for the monitoring program samples was as follows: NGSP = 1.029 × JDS + 0.216. For another sample, JDS Lot 4, the correlation was: NGSP = 1.029 × JDS + 0.187. The two equations are consistent with the cutoff points 6.5 and 6.1 %, used by the ADA and the JDS, respectively. [ABSTRACT FROM AUTHOR]

The aim of our study is to determine the predictive factors for placement of percutaneous nephrostomy tube (PNT) in percutaneous nephrolithotomy (PCNL) procedure and to evaluate the optimal cutoff points of the predictive factors. 229 patients, who had undergone percutaneous nephrolithotomy operation between February 2009 and February 2013 were reviewed retrospectively. Five patients were excluded from the study because of solitary kidney. All characteristics of 224 patients, stones and operative data were investigated. Patient and stone-related factors, such as age, BMI, history of previous surgery or SWL, characteristics of the stone, renal parenchymal thickness (RPT), as well as procedural factors, such as percutaneous access number and location were analyzed by univariate and multivariate tests. The continuous variables were analyzed using Receiver operating characteristic curve analysis. There were no differences in sex, age, BMI and hemoglobin decrease between the groups. Previous operation status, RPT, stone size, multiplicity of the stone, stone localization, blood transfusion presence, access points, access number and operation time were found statistically different according to univariate analysis. Multivariate analysis showed that RPT, operation time and stone size were the independent factors that affected the PNT insertion. For RPT, operation time and stone size, the optimal cutoff points for insertion PNT were 13.75 mm, 75.5 min and 890 mm, respectively. Tubeless PCNL should be chosen in patients with stone area less than 890 mm, and parenchymal thickness thicker than 13.75 mm and procedure with operation period <75.5 min. [ABSTRACT FROM AUTHOR]

Background: It has become important to standardize the methods of Ki-67 evaluation in breast cancer patients, especially those used in the interpretation and scoring of immunoreactivity. Therefore, in this study, we examined the Ki-67 immunoreactivity of breast cancer surgical specimens processed and stained in the same manner in one single Japanese institution by counting nuclear immunoreactivity in the same fashion. Methods: We examined 408 Japanese breast cancers with invasive ductal carcinoma and studied the correlation between Ki-67 labeling index and ER/HER2 status and histological grade of breast cancer. We also analyzed overall survival (OS) and disease-free survival (DFS) of these patients according to individual Ki-67 labeling index. Results: There were statistically significant differences of Ki-67 labeling index between ER positive/HER2 negative and ER positive/HER2 positive, ER negative/HER2 positive or ER negative/HER2 negative, and ER positive/HER2 positive and ER negative/HER2 negative groups (all P < 0.001). There were also statistically significant differences of Ki-67 labeling index among each histological grade ( P < 0.001, respectively). As for multivariate analyses, Ki-67 labeling index was strongly associated with OS (HR 39.12, P = 0.031) and DFS (HR 10.85, P = 0.011) in ER positive and HER2 negative breast cancer patients. In addition, a statistically significant difference was noted between classical luminal A group and '20 % luminal A' in DFS ( P = 0.039) but not between classical luminal A group and '25 % luminal A' ( P = 0.105). Conclusions: A significant positive correlation was detected between Ki-67 labeling index and ER/HER2 status and histological grades of the cases examined in our study. The suggested optimal cutoff point of Ki-67 labeling index is between 20 and 25 % in ER positive and HER2 negative breast cancer patients. [ABSTRACT FROM AUTHOR]

We formulated a species distribution model (SDM) for the amphidromous fish Sicyopterus japonicus on the basis of presence/absence data and confirmed its performance at various population densities. The best-fit SDM selected several environmental factors, including water depth and velocity, and performed validated prediction of presence/absence of various densities. The predicted probability of occurrence was positively correlated with the observed density. The density was positively related to habitat occupancy, suggesting that this species occupied a wide range of habitats under high densities, but only optimal habitat under low densities. Therefore, the threshold value for predicting presence/absence increased with decreasing densities. [ABSTRACT FROM AUTHOR]

The aim of this study is to determine safe fasting plasma glucose (FPG) levels. We included data on 5,960 individuals aged ≥20 years at baseline with at least one follow-up examination. Diabetes was ascertained in accordance with American Diabetes Association criteria, using standard 2-h post-challenge plasma glucose test. Multivariate restricted cubic splines Weibull regression was implemented for interval-censored survival data on incident diabetes. We used Harrell's C statistic for discrimination, Nam-D'Agostino χ for calibration, and Royston's R for variations in the outcome explained by models. During a 6-year median follow-up, 369 incident cases of diabetes were ascertained. Family history of diabetes, systolic blood pressure, waist-to-height ratio, and triglyceride-to-high-density lipoprotein cholesterol ratio, independent of FPG and each other remained associated with incident diabetes. The cubic splines model achieved good calibration (χ = 12.1) and discrimination ( C = 0.828) and explained 75% of variation in the time until incident diabetes. A J-shaped FPG-diabetes relationship was observed. Descending arm of the dose-response relationship curve corresponded to increasing FPG levels up to 4.0 mmol l, where it started increasing. The risk of incident diabetes decreased with decreasing levels of FPG down to 4.0 mmol l, where the risk stopped decreasing. Multivariate-adjusted risk of incident diabetes was zero at FPG = 5.05 mmol l. Although currently there is no firm evidence to show that early intervention among individuals with the elevated FPG levels could prevent or delay onset of diabetes, individuals with FPG levels below 5.05 mmol l could be safely reassured about their near-term risk of developing incident diabetes and screened on a less frequent basis. [ABSTRACT FROM AUTHOR]

The role of CA 15-3 in breast cancer has been widely studied by several authors. This study was designed to describe the predictivity of CA 15-3 determinations for the metastasis or second primary tumor in patients subjected to follow-up for breast cancer. All the 1,123 determinations of CA 15-3 carried out during 1991 in a hospital laboratory were analyzed. By cross-matching anagraphic items of patients with clinical data from different hospital databases, it was possible to reconstruct the clinical history. At the cutoff point of 40 U/ml, the positive predictive value of the CA 15-3 was 99.4%. This study shows the very close association between CA 15-3 ≥ 40.0 U/ml and disease, suggesting a careful restaging when the marker increases without clinical evidence of metastases. Hormonal treatment should also be considered. Copyright © 1995 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]