Improving access to diagnostics: an evaluation of a satellite laboratory service in the emergency department

To measure the impact of a satellite laboratory upon laboratory result turnaround times and clinical decision making times.

A prospective cohort study, the intervention group had blood tests sent Monday to Friday 12 noon to 8 pm and the control group had blood tests sent outside these hours. The data were collected over a six week period before the laboratory was opened, and a subsequent six week period.

An urban teaching hospital emergency department.

1065 patients requiring blood tests.

Time from the blood sample being sent to the laboratory to the results being available on the clinician's computer.

The time to haematology (blood count) results in the intervention group decreased by 47.2 minutes (95% CI 38.3 to 56.1, p<0.001) after the laboratory was opened. The corresponding control group times were unchanged (0.6 minutes; -13.8 to 15.0, p = 0.94). Similar sized differences were also seen for haemostasis (d-dimer) testing 66.1 (41.8 to 90.4) minutes compared with -14.2 (-47.1 to 18.7) and chemistry 41.3 (30.3 to 52.2) compared with -4.2 (-17.4 to 8.9) testing. Decisions to discharge patients were significantly faster (28.2 minutes, 13.5 to 42.8, p<0.0001) in the intervention group after the laboratory was opened (controls; -2.6 minutes -27.0 to 21.7). No change was seen with decisions to admit patients. There was a trend for earlier laboratory results modifying intravenous drug or fluids orders, or both (p = 0.06)

A comprehensive satellite laboratory service is an important adjunct to improve the timeliness of care in the emergency department.