Participants selected the levonorgestrel-releasing IUD or a copper IUD before undergoing uterine aspiration. All aspiration methods were performed by a study investigator or a resident physician directly supervised by a study investigator. Randomization to either immediate IUD insertion or delayed IUD insertion was accomplished by permuted-prevent randomization with random block sizes of 5 and 6, stratified by research center. Within each stratum, we randomly assigned subjects to instant or delayed insertion in an overall ratio of around 5:6 by using a ratio of 2:3 for a block size of 5 and a ratio of 3:3 for a block size of 6.The researchers studied 646 sufferers randomly selected from the waiting rooms at three academic-based internal medicine outpatient procedures, two in LA and one in NEW YORK. Of those, 48 % were white, 29 % African American, 9 % Latino and 9 % Asian American. Subjects generally had equivalent physical and mental health, though African Us citizens were likeliest to possess multiple chronic conditions. The data was collected between November 1999 and February 2000. Related StoriesIdentifying obstructive coronary artery disease in females: an interview with Dr. Ladapo, NYU School of MedicineBRCA gene mutations and ovarian cancer: an interview with Dr Matulonis, Harvard Medical SchoolCombatting viral and bacterial lung infections with volatile anesthetics: an interview with Dr ChakravarthyTest topics were asked their choices for seeing an expert for the actual health problem that brought them to their physician’s office, as well as three hypothetical scenarios: two weeks of new-onset chest pain from exerting themselves, two months of knee pain and four weeks with a rash.