Thank you for the opportunity to help you with your question!
communucation is the process of tranferring information from one party to another. adherence is the abilty of the receptive subject to do what the source of the information him/her to do, that is, it is the act of doing what is required.
a good example where the relationship between communication and adherence applies frequently is in doctor-patient relationship. the ability of the doctor to communicate clearly his treatment plan to the patient is the key to treatment of the patient
Please let me know if you need any clarification. I'm always happy to answer your questions.