Because the Health Education Program no longer requires the GRE, students must rely on other items to demonstrate that they are ready, and able, to complete graduate level work.  The Graduate Admissions Committee reviews the students' GPA, their transcripts, their essay, and their references.  It is vitally important that your references speak to your ability to conduct graduate level work.  In most instances, the Graduate Admissions Committee feels it's best to have former faculty members write on your behalf because they are most aware of the demands of graduate school.  Friends, co-workers, or employers should be avoided unless absolutely necessary and only if they can demonstrate their understanding of the demands of graduate school.  Letters written from friends, co-workers or supervisors are often viewed with lesser esteem by the Graduate Admissions Committee.  There are occasional instances where an applicant may have been out of college for decades and there are no faculty at their institution to contact.   Under those circumstances it is important to note such situations;  however, it's important that your references have a good understanding of the demands of graduate school.