A team of epidemiologists enrolls factory workers to study the effect of long-term silica dust exposure on the development of chronic lung disease. Workers are classified at enrollment as "high-exposure" (those working in processing areas) or "low-exposure" (those in administrative areas). The enrolled workers are then followed for years, with yearly clinical exams to record incident chronic lung disease. Which statement best describes what is meant by calling this a prospective cohort study?
