Related Experiment Videos

Tibolone and breast cancer risk: effects of selection bias cannot be eliminated in observational studies

A Coomarasamy

    BJOG : an International Journal of Obstetrics and Gynaecology
    |May 20, 2008
    PubMed
    Abstract

    No abstract available in PubMed .

    Related Concept Videos

    Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches01:23

    Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches

    Biopharmaceutical studies constitute a vital field aiming to enhance drug delivery methods and refine therapeutic approaches, drawing upon diverse interdisciplinary knowledge. In research methodologies, the choice between controlled and non-controlled studies significantly influences the study's reliability and accuracy.
    Non-controlled studies, commonly employed for initial exploration, lack a control group, rendering them susceptible to biases and external influences. In contrast, controlled...
    Bias in Epidemiological Studies01:29

    Bias in Epidemiological Studies

    Biases can arise at various stages of research, from study design and data collection to analysis and interpretation. Recognizing and addressing these biases is essential to ensure the validity and reliability of epidemiological findings.Broadly speaking, biases in epidemiology fall into three main categories: selection bias, information bias, and confounding. A more detailed description of possible biases is:
    Targeted Cancer Therapies02:57

    Targeted Cancer Therapies

    The targeted cancer therapies, also known as “molecular targeted therapies,” take advantage of the molecular and genetic differences between the cancer cells and the normal cells. It needs a thorough understanding of the cancer cells to develop drugs that can target specific molecular aspects that drive the growth, progression, and spread of cancer cells without affecting the growth and survival of other normal cells in the body.
    There are several types of targeted therapies against specific...
    Study Designs in Epidemiology01:20

    Study Designs in Epidemiology

    Epidemiological study designs are fundamental tools for investigating the distribution, determinants, and control of health conditions in populations. They help researchers understand the relationships between exposures and outcomes, and they broadly fall into two categories: "observational" and "experimental" studies.
    Observational studies are those where the researcher does not intervene but rather observes natural variations. They include cross-sectional, cohort, and case-control studies.
    Observational Studies01:11

    Observational Studies

    Observational studies are a type of analytical study where researchers observe events without any interventions. In other words, the researcher does not influence the response variable or the experiment's outcome.
    There are three types of observational studies – Prospective, retrospective, and cross-sectional.
    Prospective Study
    Prospective studies, also known as longitudinal or cohort studies, are carried out by collecting future data from groups sharing similar characteristics. One example of...
    Confounding in Epidemiological Studies01:27

    Confounding in Epidemiological Studies

    Confounding in statistical epidemiology represents a pivotal challenge, referring to the distortion in the perceived relationship between an exposure and an outcome due to the presence of a third variable, known as a confounder. This variable is associated with both the exposure and the outcome but is not a direct link in their causal chain. Its presence can lead to erroneous interpretations of the exposure's effect, either exaggerating or underestimating the true association. This phenomenon...