Occupation and environment in internal medicine: sentinel events and trigger questions.

Patients who undergo sentinel events indicate a breakdown in the chain of prevention and protection. Because most work- or environmentally induced illnesses and disabilities produce nonspecific or late symptoms and signs, the search for exposures to physical, toxic, ergonomic, or sociopsychological events that induce these sentinel events has to be based on systematic investigative routine, and not on the physician's mere awareness. Routine use of five "trigger" questions to identify jobs, tasks, exposures, symptoms, and other persons at risk can be effective, quick, and inexpensive in the search for preventable illness related to work or environment in the sentinel patient, especially when illness persists, recurs, or progresses or occurs in others. Sometimes, others can be helped when it is too late to do anything for the sentinel individual. This holds true for the relatively simple situations of one exposure and one outcome and for settings in which there are many exposures or many diseases in one or many patients. The newer set of "clean" environments that include ergonomic and sociopsychological hazards and stress at the work-station have produced new sentinel events. Knowledge of the impact of macro-environmental hazards presupposes familiarity with their impact on individual risks. Using the sentinel event to promote prevention of hazardous exposures means opportunities for reducing unnecessary risk in individuals and small groups. Opportunities for prevention arise when sentinel events occur at the time of exposure. Where there is latency between exposure and outcome, an anticipatory approach based on awareness of future risks from preventable current exposures is needed. The search for external exposures that have already occurred and for those that are preventable should be a routine part of internal medicine.