Purpose: Laboratory tests are very important for diagnosis and tracking of disease and usage of laboratory testing has rised with each passing day. Unnecessary laboratory testing is one of the main reasons for increased laboratory use. In this study, we aimed to investigation of unnecessary laboratory testing using fPSA test and serum lipids.

Material and Methods: fPSA tests which are ordered single and with total psa tests that values of less than 4 ng/ml or greater than 10 ng/ml were accepted as inappropriate initial testing. Total cholesterol, HDL-C and LDL-C tests which were repeated within 30 days were identified inappropriate repeat testing.

Results: 2505 of 2924 fPSA tests were evaluated as unnecessary laboratory testing. Clinic of general surgery was detected that ordered the maximum unnecessary laboratory testing rate with 88%. Percentages of inappropriate repeat testing were 5.16% for total cholesterol, 10.93% for HDL-C and 7.90% for LDL-C and it was detected that unnecessary laboratory testing of inpatient clinics were more than outpatient clinics' (p<0.01). Internal medicine outpatient clinic was determined that has the maximum rate of unnecessary laboratory testing for every three tests.

Conclusion: Unnecessary usage of laboratory tests may cause false positive results, using more diaognosis tests and invazive processes increase duration of hospital stay and healthcare costs. Therefore using of the algorithms for choosing laboratory tests and during the preparation of these algorithms collaboration between clinician-laboratory specialists is extremely important.