Bayesian and non-bayesian inference for logistic-exponential distribution using improved adaptive type-II progressively censored data.

Improved adaptive type-II progressive censoring schemes (IAT-II PCS) are increasingly being used to estimate parameters and reliability characteristics of lifetime distributions, leading to more accurate and reliable estimates. The logistic exponential distribution (LED), a flexible distribution with five hazard rate forms, is employed in several fields, including lifetime, financial, and environmental data. This research aims to enhance the accuracy and reliability estimation capabilities for the logistic exponential distribution under IAT-II PCS. By developing novel statistical inference methods, we can better understand the behavior of failure times, allow for more accurate decision-making, and improve the overall reliability of the model. In this research, we consider both classical and Bayesian techniques. The classical technique involves constructing maximum likelihood estimators of the model parameters and their asymptotic covariance matrix, followed by estimating the distribution's reliability using survival and hazard functions. The delta approach is used to create estimated confidence intervals for the model parameters. In the Bayesian technique, prior information about the LED parameters is used to estimate the posterior distribution of the parameters, which is derived using Bayes' theorem. The model's reliability is determined by computing the posterior predictive distribution of the survival or hazard functions. Extensive simulation studies and real-data applications assess the effectiveness of the proposed methods and evaluate their performance against existing methods.

Dermatologists' and Rheumatologists' Adherence to the Latest Recommendations for Screening of Hydroxychloroquine Retinopathy in Saudi Arabia: A Cross-Sectional Study.

INTRODUCTION:  Hydroxychloroquine (HCQ) is used to manage the symptoms of inflammatory rheumatic and dermatologic disorders. However, HCQ retinopathy is a serious side effect because even after the drug is discontinued, irreversible vision loss may occur and may continue to progress. According to the American Academy of Ophthalmology (AAO), the recent recommendation for HCQ dosing is ≤5 mg/kg of real body weight, with baseline ophthalmologic screening during the first year of HCQ treatment and yearly screening after five years of continuous use of HCQ medication, unless the patient is at high risk or symptoms have developed. Nonetheless, this study aims to assess dermatologists' and rheumatologists' adherence in Saudi Arabia to the 2016 AAO HCQ retinal toxicity guidelines. METHODS:  A questionnaire-based cross-sectional study was conducted on dermatologists and rheumatologists in Saudi Arabia. It was conducted between August and September 2022 and questionnaires were sent to dermatologists and rheumatologists via their professional emails or accounts. RESULTS: The collected sample consisted of 635 participants; males and females represented 54% and 46%, respectively; 47.6% were consultants; 50.1% were rheumatologists; and 49.9% were dermatologists. Approximately 28.2% of the participants reported treating one to three patients with HCQ in the previous year. Only 45.4% of the respondents stated that the ideal recommended HCQ dose for reducing the risk of retinopathy is "≤ 5 mg/kg of the real body weight." More than 50% of the respondents stated that systemic lupus erythematosus was the most common disease for which they used HCQ. Additionally, 36.5% of the physicians screened patients during the first year of HCQ treatment. We found significant associations between practice levels and specialty practice-related questions with a p-value of less than 0.05, except for the specialty practice-related question, "What is the most common disease for which you use HCQ?" with a p-value of 0.074. Also, we found significant associations between all demographic variables and screening-related variables with a p-value of less than 0.05, with two exceptions: no significant associations were found between specialty area and the screening-related question, "Do you recommend screening tests for all patients starting treatment with HCQ?" at p = 0.270, and gender and the screening-related question, "When would you recommend screening tests for a patient without risk?" at p = 0.142. CONCLUSIONS:  Dermatologists and rheumatologists in Saudi Arabia have shown poor adherence to the most recent AAO recommendations. Educating physicians and patients about the AAO guidelines is needed for HCQ to be used in a way that is both effective and safe.

Sample size determination for time-to-event endpoints in randomized selection trials with generalized exponential distribution.

Randomized selection trials are frequently used to compare experimental treatments that have the potential to be beneficial, but they often do not include a control group. While time-to-event endpoints are commonly applied in clinical investigations, methodologies for determining the required sample size for such endpoints, except exponential distribution, are lacking. In recent times, there has been a shift in clinical trials, with a growing emphasis on progression-free survival as a primary endpoint. However, the utilization of this measure has typically been restricted to specific time points for both sample size determination and analysis. This alteration in approach could wield a substantial influence on the clinical trial process, potentially diminishing the capacity to discern variances between treatment groups. In the calculation of sample sizes for randomized trials, this investigation operates under the assumption that the time-to-event endpoint conforms to either an exponential, Weibull, or generalized exponential distribution.

Some developments on seasonal INAR processes with application to influenza data.

Influenza epidemic data are seasonal in nature. Zero-inflation, zero-deflation, overdispersion, and underdispersion are frequently seen in such number of cases of disease (count) data. To explain these counts' features, this paper introduces a flexible model for nonnegative integer-valued time series with a seasonal autoregressive structure. Some probabilistic properties of the model are discussed for general seasonal INAR(p) model and three estimation methods are used to estimate the model parameters for its special case seasonal INAR(1) model. The performance of the estimation procedures has been studied using simulation. The proposed model is applied to analyze weekly influenza data from the Breisgau- Hochschwarzwald county of Baden-Württemberg state, Germany. The empirical findings show that the suggested model performs better than existing models.

Laboratory Abnormalities in Acne Patients Treated With Oral Isotretinoin: A Retrospective Epidemiological Study.

Background Isotretinoin has been used to treat moderate to severe acne. It is well known that isotretinoin can cause an elevation in liver enzymes, triglycerides, and cholesterol. Laboratory monitoring is indicated while patients are on isotretinoin, but the frequency of laboratory monitoring is very variable among physicians who prescribe it. Study objectives This study aimed to determine the frequency of laboratory abnormalities of triglycerides, cholesterol, and liver aminotransferases in acne patients treated with oral isotretinoin in order to assess the need for frequent laboratory monitoring while on isotretinoin and to study the association between body weight and laboratory abnormalities. Methods A retrospective chart review has been conducted using data extracted from electronic medical records of the Department of Dermatology, Qassim University Medical City, Saudi Arabia. We included all acne patients who were treated with Isotretinoin for at least four months. Data were analyzed using the statistical program SPSS version 25 (Armonk, NY: IBM Corp.). Results A total of 407 patients met the inclusion criteria and were included in our study, 198 (48.6%) were female and 209 (51.4%) were males. Patients' age ranged from 10 to 51 years, with a mean age of 22.15 years. At baseline, aspartate aminotransferase (AST) was elevated in 5.4% of patients and alanine aminotransferase (ALT) was elevated in 12.7% of patients. At the last visit, AST was elevated in 3.9% of patients while ALT was elevated in 9% of patients. Triglycerides level was elevated in 12.7% of patients at the last visit compared to 6.5% of patients at baseline. Total cholesterol was elevated in 9% of patients at the last visit compared to 10.5% of patients at baseline. The increase in triglyceride levels and differences between triglycerides (TG) classifications between baseline and last visit was statistically significant (P<0.001). Higher body weight was associated with a higher incidence of elevation in ALT and triglycerides levels, and this association was statistically significant. There was no statistically significant relationship between total cumulative dose and laboratory abnormalities in ALT, AST, triglycerides, or total cholesterol. Conclusion The findings of this study indicate that oral isotretinoin can cause an elevation in ALT, AST, total cholesterol, and triglyceride levels but the incidence of these laboratory abnormalities is low and the elevation was not associated with significant morbidity, and therefore the practice of monthly laboratory monitoring for all patients while on isotretinoin needs to be revised as there is no strong evidence for such practice. We also found that patients with higher body weight are at higher risk of laboratory abnormalities and may require more frequent laboratory monitoring. Our findings support less frequent laboratory monitoring for acne patients on isotretinoin who had normal baseline labs. Frequent laboratory monitoring in these patients carries financial and emotional implications and lacks strong evidence to support this practice.