No abstract available.
Proportional Hazards Models* ; Survival Analysis*

This brief note describes the principles of survival analysis. Survival analysis is method for studying the time between entry to a study and a subsequent event and is used frequently in neurointervention studies. Kaplan-Meier estimator is nonparametric method for estimating the survival curve and log rank test is used for comparing between exposure and non-exposure groups. Proportional hazards model, a semi-parametric regression model specifically developed for censored data, is used when there are many exposure variables.
Proportional Hazards Models ; Survival Analysis*

Humans ; Pneumoconiosis ; mortality ; Proportional Hazards Models

Prevalence ; Proportional Hazards Models ; Regression Analysis

OBJECTIVE: To realize batch processing of univariate Cox regression analysis for great database by SAS marco program. METHODS: We wrote a SAS macro program, which can filter, integrate, and export P values to Excel by SAS9.2. The program was used for screening survival correlated RNA molecules of ovarian cancer. RESULTS: A SAS marco program could finish the batch processing of univariate Cox regression analysis, the selection and export of the results. CONCLUSION The SAS macro program has potential applications in reducing the workload of statistical analysis and providing a basis for batch processing of univariate Cox regression analysis.
Proportional Hazards Models ; Regression Analysis ; Software

Safety is vital in any industry, including the offshore sector, which is classified as a major hazard industry. Health, Safety and the Environment (HSE) identified that the probability of accidents is high while working on the offshore sectors where it will exposed workers to many hazardous work activities. The appropriate measures to prevent accident in this sectors must be laid out clearly. This paper is to identify the effectiveness of safety awareness campaign and the continuity of the awareness among the workers to prevent injuries at offshore. To achieve this, we have identified the level of awareness and propose a guideline on areas of improvement. Prior of embarking to offshore, staff were exposed to safety awareness program for four weeks. After the program, we started with the pretest to all staff. They were posted offshore for 6 weeks. Within the period, the performance awareness of each staff is monitored through observation and interview. During the final week, the posttest questionnaire were administered to all staff. Two instruments were used for the quantitative data collection, which are Unsafe Act Unsafe Condition (UAUC) card; and Behavior Observation Tool (BOT) card. Questionnaire data were analyzed quantitatively. Paired-sample t-test was used for analyzing pre and post result. The results show that the mean was increased. Recent studies on the safety briefing highlighted several significant changes in terms of employee understanding toward safety. Safety awareness training has been introduced in the new safety briefing prior to offshore mobilization.
Offshore Sector ; HSE ; Hazards ; Unsafe Act/Unsafe Condition ; Behaviour Observation

Follow-Up Studies ; Humans ; Proportional Hazards Models ; Survival Analysis

Musculoskeletal Discomfort And Its Associated Risk Factors Among Train Drivers This study was conducted to determine the prevalence and associated risk factors of musculoskeletal disorders among train drivers in Kuala Lumpur. In this cross-sectional study, 44 train drivers were interviewed using a self-administered questionnaire consists of socio-demographic information and occupational exposure; and a modified Nordic Standardised Questionnaire for questions related to musculoskeletal discomfort symptoms. Results showed that lower back (18.6%) are the most reported discomfort among train drivers, followed by neck (16.7%), knee (13.7%), and upper back (13.7%). Statistical analysis using Chi-square showed there is a significant association between discomfort in the neck with age (p<0.05), length of service (p<0.05), and the perception of driver’s seat comfort and suitability (P<0.001). Previous working experience, driving duration, and shift work were associated with shoulder, wrist and thigh discomfort. This study suggested that further investigation and early control measure need to be done to prevent the risk of the musculoskeletal problem among train drivers.
musculoskeletal disorders ; occupational hazards ; ergonomics ; freight ; cargo ; locomotive ; prevalence.

OBJECTIVE: To explore the application and advantages of conditional inference forest in survival analysis. METHODS: We used simulated experiment and actual data to compare the predictive performance of 4 models, including Coxproportional hazards model, accelerated failure time model, random survival forest model and conditional inference forest model based on their Brier scores. RESULTS: Simulation experiment suggested that both of the two forest models had more accurate and robust predictive performance than the other two regression models. Conditional inference forest model was superior to the other models in analyzing time-to-event data with polytomous covariates, collinearity or interaction, especially for a large sample size and a high censoring rate. The results of actual data analysis demonstrated that conditional inference forest model had the best predictive performance among the 4 models. CONCLUSIONS Compared with the commonly used survival analysis methods, conditional inference forest model performs better especially when the data contain polytomous covariates with collinearity and interaction.
Data Analysis ; Proportional Hazards Models ; Sample Size ; Survival Analysis

OBJECTIVE: To investigate the gene mutation in adult patients with B-ALL and its influence on clinical prognosis. METHODS: Clinical data of 226 adult patients with B-ALL were retrospectively analyzed in the period from August 2011 to February 2018. The incidence of gene mutation in all patients were detected, and the influence of mutation gene on clinical prognosis were estimated. Cox regression model were used to evaluate the independent prognostic factors. RESULTS: 208 (92.04%) of 226 patients showed gene mutations, and the median mutation number was 2 (0-8). Among them, 54 cases (23.89%) showed 14 or more mutations. The top five mutation types of all patients were SF1, FAT1, MPL, PTPNII and N-RAS respectively. The median OS and median RFS times of 226 patients were 27.0 (5.5-84.0) months and 22.5 (0-81.0) months respectively. The OS and RFS times of Ph CONCLUSION Gene mutations are common in all adult B-ALL patients, and the clinical prognosis of patients with JAK and epigenetics-related signaling pathway mutations is worsen, while the WBC level closely relates to the clinical prognosis of the patients.
Adult ; Humans ; Mutation ; Patients ; Prognosis ; Proportional Hazards Models ; Retrospective Studies