A slang or jargon term for a substance or phenomenon that indicates what is happening and how a process works. A “tracer condition” is one that is easily diagnosed and that indicates by its prevalence a significant way in which the health care system is performing. For instance, a high prevalence of uncorrected refractive error indicates inadequate optometry or ophthalmic services. A tracer substance may be used in many ways, for instance, fluorescein dye is used as a tracer to detect possible seepage from sewer pipes to water-supply pipes.
Subjects: Public Health and Epidemiology — Meteorology and Climatology.