Screening in non-communicable disease epidemiology is designed to identify asymptomatic individuals early before clinical symptoms manifest. This allows for timely intervention, which can slow disease progression, improve outcomes, and reduce complications. It is not meant for treating advanced disease or preventing infections, nor does it replace vaccination programs. Early detection through screening is crucial in managing diseases such as diabetes, hypertension, and cancer.

Reference: Epidemiology, Leon Gordis, 5th Edition.