This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Epidemiology, Subject name: Social & Preventive Medicine
[{'content': 'Which of the following is true about incidence? \nSelect and explain. \nA. Used for chronic conditions, B. Measures old & new cases, C. More than prevalence, D. Not affected by duration', 'role': 'user'}, {'content': 'Answer: D \nExplanation: INCIDENCE Incidence rate is defined as "the number of NEW cases occurring in a defined population during a specified period of time". It will be seen from the above definition that incidence rate refers a. only to new cases b. during a given period (usually one year) c. in a specified population or "population at risk", unless other denominators are chosen. d. it can also refer to new spells or episodes of disease arising in a given period of time, per 1000 population. Ref : Park 23rd edition Pgno : 59', 'role': 'assistant'}]