Determination and classification of inappropriate test requests, investigation of their causes, and evaluation of their impact on the laboratory budget

Objective: Laboratory tests are one of the highest-volume activities in healthcare. Although these tests account for only 3-5% of total medical costs, they guide 70% of medical decisions. Thus playing an important role in determining subsequent, more costly procedures. It is estimated that 20-30% of requested tests are of low value (inadequate, unnecessary, or misused). The primary goal of laboratory testing is to produce results that are beneficial to the patient. This can be achieved by promoting the appropriate use of laboratory tests, which involves correct test requests and effective utilization of results. In aim of this study is to retrospectively analyze the records of certain biochemical test parameters and patient data who applied to the Central Laboratory of Balcalı Hospital in 2022 through the system, identify and classify inappropriate test requests, investigate their causes, and evaluate their impact on the laboratory budget. Additionally, suggestions will be made regarding measures and interventions that can be taken to reduce the number and cost of inappropriate test requests. Materials and Methods: In this study, selected biochemical tests and patient data were retrospectively screened through the Laboratory Information Management System (LIMS) and the Hospital Information Management System (HIMS) and inappropriate test requests were identified based on objective information provided in clinical guidelines. The rates of inappropriateness of these tests were evaluated using Microsoft Excel. The financial burden of the inappropriate tests on our hospital and the state was calculated. Results: It was observed that the number of tests per patient in emergency requests was higher compared to routine requests. Among these, 94.21% of myoglobin requests and 42.2% of CKMB requests were identified as inappropriate. The inappropriate requests rate for simultaneous TSH, sT4, and sT3 was found to be 32.33%. Additionally, 50.57% of CA15.3, CA125, and CA19.9 requests, as well as 73.63% of sPSA requests, were deemed inappropriate. Furthermore, 86.60% of AST requests and 70.34% of direct bilirubin requests were inappropriate. For 25-hydroxy vitamin D, 0.38% of requests were inappropriate, while for HbA1c, B12 vitamin, and folate, the inappropriate request rates were 3.42%, 20.34%, and 37.79%, respectively. Among total calcium, ionized calcium, and albumin requests, 78% were found to lack sufficient albumin, and 0.089% were deemed unnecessary ionized calcium requests. The total financial cost of inappropriate test requests to the laboratory and the state was calculated as 1,271,724 TL and 5,598,865 TL, respectively. Conclusion: The use of laboratory tests has increased over time and is expected to continue rising in the future. In our laboratory, the rates and costs of inappropriate test requests for certain biochemical parameters have been identified, and recommendations have been made regarding the possible causes of inappropriate test requests, as well as preventive measures and interventions. There is a growing need to develop and expand studies aimed at the rational use of laboratories, and it is hoped that our study will serve as a useful guide in this regard and contribute to the development of "green laboratories." Keywords: Inappropriate Test Request, Rational Laboratory Use, Laboratory Test, Cost