Complex sentence: This empowerment model has evolved out of the realization that patients cannot be forced to follow a lifestyle dictated by others; proponents thus argue that preventive medicine actually requires patient empowerment for it to be effective.
Split into simpler sentences: This empowerment model has evolved out of the realization that patients cannot be forced to follow a lifestyle dictated by others. Thus, preventive medicine actually requires patient empowerment for it to be effective.