Introduction to clinical research based on modern epidemiology

Abstract

Over the past 20 years, recent advances in science technologies have dramatically changed the styles of clinical research. Currently, it has become more popular to use recent modern epidemiological techniques, such as propensity score, instrumental variable, competing risks, marginal structural modeling, mixed effects modeling, bootstrapping, and missing data analyses, than before. These advanced techniques, also known as modern epidemiology, may be strong tools for performing good clinical research, especially in large-scale observational studies, along with relevant research questions, good databases, and the passion of researchers. However, to use these methods effectively, we need to understand the basic assumptions behind them. Here, I will briefly introduce the concepts of these techniques and their implementation. In addition, I would like to emphasize that various types of clinical studies, not only large database studies but also small studies on rare and intractable diseases, are equally important because clinicians always do their best to take care of many kinds of patients who suffer from various kidney diseases and this is our most important mission.

Development and Validation of a Predictive Scoring System for In-hospital Death in Patients With Intra-Abdominal Infection: A Single-Center 10-Year Retrospective Study

“…Internal validation of the established predictive scoring model was performed using the 1,000 bootstrapping sample method, which entails creation of new random datasets (bootstrapping sample datasets) from the original dataset by resampling the sample data with replacement. The distribution of statistics of the bootstrapping sample datasets will be approximately equal to the distribution of the original sample statistics ( 8 ). In the present study, the C-index and 95% confidence interval (CI) across the bootstrapping sample datasets were used to evaluate the stability of the established predictive scoring model.…”

Pesquisa Clínica e Câncer

“…Antes que qualquer ensaio clínico seja sequer enviado ao Comitê de Ética pertinente, deve ser desenvolvido a partir de uma pergunta científica relevante, apresentar um desenho de estudo e ferramentas de análise apropriados, e depender de uma base de dados de alta qualidade que possa ser compreendida por qualquer investigador e reanalisada, caso necessário. Quanto aos fundamentos da pesquisa clínica, o que também se aplica em oncologia, fazem-se essenciais a definição de uma população-alvo, dos grupos de exposição ou intervenção, comparações e desfechos a serem avaliados 5 .…”