Laboratory Tests Ordering Pattern by Medical Residents From a Brazilian University Hospital

Objectives: The adequacy of laboratory test orders by medical residents is a longstanding issue. The aim of this study is to analyze the number, types, and pattern of repetition of tests ordered by medical residents.

Methods: We studied all tests ordered over a 1-year period for inpatients of an internal medicine ward in a university hospital. Types, results, and repetition pattern of tests were analyzed in relation to patients' diagnoses.

Results: We evaluated 117,666 tests, requested for 1,024 inpatients. The mean number of tests was 9.5 per day. The test repetition pattern was similar, regardless of patients' diagnoses, previous test results, or duration of stay. The probability of an abnormal result after a sequence of three normal tests was lower than 25%, regardless of the diagnosis.

Conclusions: Number of tests and repetition were both high, imposing costs, discomfort, and risks to patients, thus warranting further investigation.