Physicians do experience exposure to occupational hazards, and there is a well-known aphorism that "doctors make the worst patients".[35] Causes of death that are shown to be higher in the physician population include suicide among doctors and self-inflicted injury, drug-related causes, traffic accidents, and cerebrovascular and ischaemic heart disease.[2] Physicians are also prone to occupational burnout. This manifests as a long-term stress reaction characterized by poorer quality of care towards patients, emotional exhaustion, a feeling of decreased personal achievement, and others. A study by the Agency for Healthcare Research and Quality reported that time pressure was the greatest cause of burnout; a survey from the American Medical Association reported that more than half of all respondents chose "too many bureaucratic tasks" as the leading cause of burnout.[36][37]