Historically, infectious diseases were the primary focus of epidemiologists. However, with advances in sanitation, vaccination, and antibiotics, the burden of infectious diseases has decreased in many parts of the world. This shift has led to a greater emphasis on NCDs, which now account for a significant proportion of global morbidity and mortality.
In recent decades, the rise of lifestyle-related diseases such as obesity, diabetes, and mental health disorders has prompted a reallocation of resources and research efforts. The opioid crisis, particularly in the United States, has also emerged as a critical public health challenge, necessitating targeted epidemiological studies to inform effective interventions.
