Needle-stick injuries. Healthcare workers are at risk of being exposed to blood-borne pathogens through needle-stick and other sharp object injuries. The pathogens of primary concern are the human immunodeficiency virus, hepatitis B virus, and hepatitis C virus. When a needle-stick injury occurs, workers report the incident to their supervisor. This information is forwarded to county health departments and ultimately to the Centers for Disease Control and Prevention (CDC). A CDC researcher uses these data to compare needle-stick injuries in community hospitals and tertiary-care hospitals. Is this a paired or independent comparison? Explain your answer.