Which of the following is true about Secular trend -
Ans. is 'd' i.e., Consistent change in a paicular direction over a period of time The term 'Secular trend' implies changes in the occurrence of disease i.e. a progressive increase or decrease in incidence over a long period of time, such as several years or decades.
Road side accident is a good example
Due to environmental factors
Is due to normally occuring variation in herd immunity
Consistent change in a paicular direction over a period of time