Final answer:
The International Classification of Diseases (ICD) was the classification system used in the US to report morbidity and mortality information until September 30, 2015, it helps classify diseases and provides updates on public health issues through the Morbidity and Mortality Weekly Report (MMWR).
Step-by-step explanation:
The classification system used in the US to report morbidity and mortality information until September 30, 2015, was the International Classification of Diseases (ICD). This system is deployed by the World Health Organization (WHO) and is imperative in clinical fields for classifying diseases, and monitoring morbidity, which is the number of cases of a disease, and mortality, the number of deaths due to a disease. The ICD plays a crucial role in epidemiological studies and helps inform healthcare providers and the public about potential health risks by providing updates on public health issues and the latest data on notifiable diseases through publications such as the Morbidity and Mortality Weekly Report (MMWR), published by the Centers for Disease Control and Prevention (CDC).