Analysis of blood tests in the emergency department of a tertiary care hospital.

There is ample evidence that many investigations sent from the accident and emergency department are inappropriate, thus affecting the quality of patient care. A study was designed to address this issue in the emergency department of a tertiary care hospital of a large city. A prospective cross-sectional study was carried out during the 3-month period 1 December 1996 to 28 February 1997. A set of guidelines was used to assess the appropriateness of different blood tests for the initial assessment of the patients presenting with common clinical conditions, although any investigation could be done if considered important for patient management. All other blood tests were considered inappropriate. A total of 6401 patients were seen in the emergency department and 14,300 blood tests were done on 3529 patients with diagnoses covered by the guidelines. Of these 62.2% were found to be inappropriate. Of the total 22,655 investigations done on all the 6401 patients seen, only 3.8% influenced the diagnosis, 3.0% influenced patient care in the emergency department, and 4.0% influenced the decision to admit or not. Amylase and arterial blood gases were found to be the most appropriate investigations. Analysis of reasons for unnecessary use of emergency tests suggested that improving supervision, decreasing the utilization of the emergency department as a phlebotomy service for the hospital, and abolition of routine blood tests would help to improve patient care.