Final answer:
Epidemiology is a branch of public health that studies disease patterns, causes, and effects in populations, employing measures like incidence and prevalence to assess health events. It informs health policies by revealing risk factors and the overall health of populations.
Step-by-step explanation:
Descriptive Epidemiology and Disease Impact
Epidemiology is a pivotal science in understanding the patterns, causes, and effects of diseases within human populations. It has expanded from focusing solely on infectious disease epidemics to include a wide array of health events such as chronic diseases, environmental factors, and injuries. An epidemiologist employs statistical measures like incidence and prevalence to track disease frequency and spread. Incidence calculates new cases within a specific timeframe, helping to pinpoint risk factors and modes of disease transmission. Prevalence captures both new and existing cases, offering insight into the general health of a population over time. As part of public health, epidemiology forms the basis for shaping health policy and preventive healthcare initiatives.
Epidemiologists also focus on the distribution of diseases, distinguishing between epidemics, widespread diseases, and endemics, diseases that are consistently present at low levels. In addition to studying the biological and environmental factors, social epidemiology examines how social structures influence the distribution of diseases, revealing the differing health problems between high-income and low-income populations.