Methods of statistical analysis of censored survival times are briefly reviewed and illustrated by application to clinical trials data. These include estimation of the survival curce, nonparametric tests to compare several survival curves, tests for trend, and regression analysis. Extensions of the methodology are made for application to epidemiologic case-control studies. These are used to est...

background: tobacco smoking is the leading cause of preventable mortality. the prevalence of smoking in adolescents in high schools ranges from 23.5% to 41%, respectively. in colombia, these figures are similar and students entering the university are exposed to initiate smoking. the purpose of this study was to establish the determinants associated with the initiation of tobacco smoking among ...

OBJECTIVES To determine the trend of hypospadias incidence in New York State (NYS) by retrospectively evaluating both the incidence and surgical repair rates of hypospadias. Epidemiologic studies in the United States and Europe have suggested an observable trend in the incidence of hypospadias during the past 30 years. A comparison of the results from these studies, however, revealed inconsiste...

A survey on opium use was earned out in Tinsukia district of upper Assam to assess the present prevalence and pattern of opium abuse and compared with earlier findings of the year 1981 (Baruah et al., 1995). A total of 75 addicts could be detected during the survey and 61 were interviewed using structured questionnaire. The results indicate significant decline in prevalence in opium use over th...

OBJECTIVE This study was aimed to find out epidemiologic characteristic of tuberculosis (TB) cases, and Human Immunodeficiency Virus (HIV) positive cases among TB patients (TB/HIV co-infection) through demographic, temporal, and spatial study in Urumqi. METHODS Descriptive statistics and multivariate logistic regression were applied to identify the epidemiologic characteristics and risk facto...

A recent article in the Journal by Whelton et al. (Am J Epidemiol. 2013;178(7):1076-1084) prompted this commentary about the use of the word "elevated" in medical reports. We believe that the word used in that particular report should have been "higher." The exposure variable was not actually elevated according to what we understand the word to mean in epidemiologic research. Consistent with th...

Since the first reported case of severe fever with thrombocytopenia syndrome (SFTS) in South Korea in 2013, between 2013 and 2015, we collected 1,697 serum samples from suspected patients who experienced symptoms of SFTS. We performed reverse transcriptase polymerase chain reaction using total RNA extracted from the patients' sera. When viral RNA was detected in the sera, SFTS was diagnosed. Am...

This paper presents information on Japan's contribution to reputable epidemiologic journals as compared to other leading countries. Ten journals in the field of epidemiology with high impact factors were selected. Articles published in these journals during the period between 1991 and 2000 were searched for the authors' affiliation using Medline database. We found that Japan contributed only 1....