New cases are they incident or newly discovered / 中华疾病控制杂志

ABSTRACT

@#New case is a basic concept in epidemiology and often serves as the numerator for the indexes of the frequency of disease in a population． However，the exact definition of new case is still un- clear． Based on the natural history of disease combined with the concept of event-state，this article rede- fines case-related concepts and compares them with traditional concepts． The study found that the so- called new cases in traditional epidemiological studies are actually the cases firstly discovered，including newly discovered cases and identifiable newly incident cases ( disease initiation) ． In the real world，new cases are often difficult to measure，and together with the continuous process of disease development and iceberg phenomenon，those may affect the accuracy of disease frequency measurement and causal infer- ence． A correct understanding of the meaning of case-related concepts，the meanings they reflect，and the differences between them help to rationally interpret the results of epidemiological research．