"The" association between socioeconomic conditions and health differed between countries of different economic development.
I know that "The" implies a particular association that is between "socioeconomic conditions" and "health".
But, What if I remove "the" before association? Like below:
Association between socioeconomic conditions and health differed between countries of different economic development.
There is still a sense of a 'particular association' that is between socioeconomic conditions and health. So, what is the need of using "the"?