Laboratory services utilization: a survey of repeat investigations in ambulatory care

Earlier studies have shown that repeat investigations are a common cause of unnecessary duplication of laboratory test procedures. Most of the interventions aimed at reducing the number of repeat investigations have not resulted in long-term improvements. None of these studies, however, assessed utilization of laboratory services by physicians, simultaneously treating the same patient.

For a random sample of 1500 patients, we examined laboratory services utilization by physicians during an 8-month period. We counted the number of patients for whom more than one physician ordered laboratory test procedures simultaneously, and to what extent these procedures overlapped.

For 28% of the patients more than one physician had ordered tests. Of all 41,655 tests, 5536 (13%) were repeated by a physician other than the physician who ordered the initial test: 1527 (4%) of the tests were repeated within 5 days. Patients between 70 and 90 years had the highest average number of tests, the highest number of involved physicians, and the smallest mean time between similar tests.

There is a need for better coordination of care. Improved communication among physicians simultaneously treating a patient may lead to a reduction of repeat investigations.