Overdiagnosis: epidemiologic concepts and estimation

Overdiagnosis: epidemiologic concepts and estimation

Overdiagnosis of thyroid cancer was propounded regarding the rapidly increasing incidence in South Korea. Overdiagnosis is defined as 'the detection of cancers that would never have been found were it not for the screening test', and may be an extreme form of lead bias due to indolent cancers, as is inevitable when conducting a cancer screening programme. Because it is solely an epidemiological...

Cancer, concepts, cohorts and complexity: avoiding oversimplification of overdiagnosis.

INTRODUCTION A cancer diagnosis strikes intense fear in us, and for good reason. Cancer is the leading cause of death in people aged less than 85 years, and is viewed as a death sentence which few can escape. Lung cancer is particularly ominous, accounting for more than the next three leading causes combined. However, the National Lung Screening Trial provides hope, demonstrating 20% less lung ...

Estimation of Overdiagnosis in Breast Cancer Screening

I. Summary The benefit of breast cancer (BC) screening with mammography has been demonstrated by randomized controlled trials (RCTs). However, there is a growing concern about the harms of screening, in particular the problem of overdiagnosis. It occurs when screening detects a breast cancer that would not have presented clinically in the woman's lifetime in the absence of screening. Overdiagno...

Epidemiologic Measurement: Basic Concepts and Methods

Sample size estimation in epidemiologic studies

This review basically provided a conceptual framework for sample size calculation in epidemiologic studies with various designs and outcomes. The formula requirement of sample size was drawn based on statistical principles for both descriptive and comparative studies. The required sample size was estimated and presented graphically with different effect sizes and power of statistical test at 95...