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
True regarding secular trends- 
Select and explain. 
A. Changes in disease pattern in terms of months, B. Changes in disease pattern seasonally, C. Changes in disease pattern over a sho period of timer, D. Changes in disease pattern over a long period of time
D: Changes in disease pattern over a long period of time
Answer: D: Changes in disease pattern over a long period of time 
Explanation: .long term or secular trends implies changes in the occurrence of disease over a long period of time.generally several years or decades.a secular trend implies a consistent tendency to change in a paicular direction or a definitive movement in one direction. ref:park&;s textbook,ed 22,pg no 63