A cost-effectiveness evaluation of reticulocyte measurement in new outpatients with or without hematologic disorders

Although reticulocyte counts provide very useful information, few studies have analyzed the cost-effectiveness of this testing.

The yield and cost of reticulocyte count testing were analyzed in 719 new outpatients who visited the comprehensive medicine clinics and received both reticulocyte and complete blood count (CBC) testing. A "useful result" (UR) of the testing was defined as a finding that contributed to a change in a physician's diagnosis or decision-making between the pre- and post-test diagnosis. Patients' medical records were thoroughly reviewed for the assignment of URs. A simulation study was performed, blinding the reticulocyte data to the examiners, for the determination of URs generated by CBC alone.

CBC and reticulocyte testing generated a total of 838 URs in 719 patients, while the simulation study demonstrated 612 URs with CBC testing alone. When patients were grouped into 11 major disease categories according to a pre-test diagnosis, clinical effectiveness (UR/patient) varied from 1.69 (hematologic) to 0.13 (metabolic/endocrine patients), with a cost disparity from 206yen to 2784yen/UR. The cost-effectiveness (Deltacost/DeltaUR) of reticulocyte addition against CBC alone was 515yen per additional UR as a whole. Reticulocyte testing showed favorable cost-effectiveness in gastrointestinal ( 234yen) and hematologic patients ( 338yen/additional UR), while the test added few URs in metabolic/endocrine and neurologic patients, resulting in possibly unacceptable cost-effectiveness ( 3240yen and 2916yen/additional UR, respectively).

Wide disparity in its cost-effectiveness among patients apparently indicated that reticulocyte count testing should be performed for selected patient groups on the basis of its cost-effectiveness.