 Data collection took place from 8:00 am to midnight seven days a week at one institution and 24 hours a day, seven days a week at the other. Data were collected on a standardized data collection instrument by trained fluently bilingual Spanish and English Research Associates. The Research Associates attended a three-day course in research ethics, and specific data collection procedures of the study. This was followed by a two-week internship during which new Research Associates were paired with more experienced Research Associates. 