Conformal normal curvature and detection of masked observations in multivariate null intercept measurement error models.

Measurement errors occur very commonly in practice. After fitting the model, influence diagnostics is an important step in statistical data analysis. The most frequently used diagnostic method for measurement error models is the local influence.

Safety-Stock: Predicting the demand for supplies in Brazilian hospitals during the COVID-19 pandemic.

Many challenges lie ahead when dealing with COVID-19, not only related to the acceleration of the pandemic, but also to the prediction of personal protective equipment sets consumption to accommodate the explosive demand. Due to this situation of uncertainty, hospital administration encourages the excess stock of these materials, over-stocking products in some hospitals, and provoking shortages in others. The number of available personal protective equipment sets is one of the three main factors that limit the number of patients at a hospital, as well as the number of available beds and the number of professionals per shift.

Fast inference for robust nonlinear mixed-effects models.

The interest for nonlinear mixed-effects models comes from application areas as pharmacokinetics, growth curves and HIV viral dynamics. However, the modeling procedure usually leads to many difficulties, as the inclusion of random effects, the estimation process and the model sensitivity to atypical or nonnormal data. The scale mixture of normal distributions include heavy-tailed models, as the Student-, slash and contaminated normal distributions, and provide competitive alternatives to the usual models, enabling the obtention of robust estimates against outlying observations.

Longitudinal follow-up of bipolar disorder in women with premenstrual exacerbation: findings from STEP-BD.

Objective: The impact of hormonal fluctuation during the menstrual cycle on the course of bipolar disorder is poorly understood. The authors determined the course of illness and time to relapse of bipolar disorder in prospectively followed women with premenstrual exacerbation.

Method: Participants were 293 premenopause-age women with bipolar disorder who were followed prospectively for 1 year as part of the Systematic Treatment Enhancement Program for Bipolar Disorder.