Assessment of statistical methods used in Chilean medical literature Evaluación de utilización de los métodos estadísticos en la investigación en salud

Background: Computer use has lead to a great development of statistical methods. Aim: To assess the use of statistical methods in Chilean medical literature. Methods: Two hundred sixty four papers appeared in Revista Médica de Chile and Revista Chilena de Pediatría between 1983 and 1993 were reviewed. Results: Student's "t", Fisher's, and χ2 test are the most frequently used statistical methods in 67% of papers. Correlation coefficients are used in 10% of papers. Multivariate methods are seldom used. Conclusions: Statistical analysis of papers published in Chilean medical journals is restricted to very few methods

Comparison of acute myocardial infarction evolution in men and women Infarto agudo del miocardio en Chile: Diferencias entre hombres y mujeres en su evolución y pronóstico

Background: Gender may be a prognostic factor for the evolution of acute myocardial infarction and women may have higher mortality and complication rates. Aim: To study if there are differences in the evolution of acute myocardial infarction between men and women. Patients and methods: We have recorded information on risk factors, clinical evolution, treatment and complications of 2052 patients hospitalized for acute myocardial infarction in 36 Chilean hospitals. The odds ratio for female sex and mortality was calculated using a logistic regression analysis adjusted for risk factors, treatment, invasive procedures and complications. Results: Twenty six percent of analyzed patients were female. Mortality rates among females and males were 11.8 and 20.2% respectively (p< 0.01). Women had higher frequency of smoking, diabetes, obesity and hypertension. Blood lipid levels were similar in both sexes. Compared to men, a lesser proportion of women were treated with thrombolytic agents (25 an

Hierarchical clustering analysis to detect associations between clinical and pathological features of gastric tumors and hypermethylation of suppressor genes Identificación de asociaciones clínico-patológicas e hipermetilación de genes supresores de tumor

Background: Methylation is an inactivation mechanism for tumor suppressor genes, that can have important clinical implications. Aim: To analyze the methylation status of 11 tumor suppressor genes in pathological samples of diffuse gastric cancer. Material and methods: Eighty three patients with diffuse gastric cancer with information about survival and infection with Epstein Barr virus, were studied. DNA was extracted from pathological slides and the methylation status of genes p14, p15, p16, APC, p73, FHIT, E-caderin, SEMA3B, BRCA-1, MINT-2 y MGMT, was studied using sodium bisulphite modification and polymerase chain reaction. Results were grouped according to the methylation index or Hierarchical clustering (TIGR MultiExperiment Viewer). Results: Three genes had a high frequency of methylation (FHIT, BRCA1, APC), four had an intermediate frequency (p15, MGMT, p14, MINT2) and four had a low frequency (p16, p73, E-cadherin, SEMA3B). The methylation index had no association with clinic

Usefulness of thrombolytic therapy with low doses of streptokinase in acute myocardial infarction Utilidad de la terapia trombolítica con estreptokinasa a dosis baja en infarto agudo del miocardio

Background: The optimal dose of Streptokinase in the treatment of acute myocardial infarction is not well established. Apparently, the thrombolytic efficacy would not increase with doses over 750.000 units. Aim: To compare the effectiveness and safety of treatment with low doses of Streptokinase, ranging from 500.000 to 750.000 units, in patients with ST elevation acute myocardial infarction. Patients and methods: From September 1993 to September 1998, the GEMI register of patients with acute myocardial infarction, was carried out in 37 hospitals, incorporating 4,938 patients. Of these, 1,631 patients received Streptokinase. According to the administered dose of Streptokinase, patients were divided in two groups: 1,465 patients who received 1.5 millions U in 60 minutes (classical therapy group), and 166 patients with ischemic chest discomfort and either ST-segment elevation or left bundle-branch block on the electrocardiogram, who received 500.000 to 750.000 U streptokinase administer