<prompt> Secular trend means -Seasonal changesPeriodical changesReligion changesLong term changes  <response>: Long term or secular trends The term secular trend implies changes in the occurrence of disease over a long period of time, generally several years or decades.There may be progressive increase or decrease in the occurrence of disease.Examples -CHD, lung cancer, and DM have shown a consistent upward trend in developed countries.TB, typhoid fever, diphtheria and polio have shown a declined trend in developed countries. 