The principles and pitfalls of screening in primary care

Abstract

Screening is the investigation of undiagnosed disease in asymptomatic patients. Asymptomatic disease tends to occur before symptomatic disease, meaning screening should identify disease earlier in its course. Early disease is usually easier to treat, with less morbidity and mortality. Therefore, in theory, screening should reduce morbidity and mortality from disease. The UK has a national population screening programme for specific diseases. Also, GPs regularly perform health screening such as the NHS health check. This must be evidence-based, so that the benefits outweigh harms, and the process must be economical. Therefore, it is important to understand the principles and pitfalls of screening.