Evaluation of Add-on Testing in the Clinical Chemistry Laboratory of a Large Academic Medical Center: Operational Considerations

Abstract

Abstract Context.—Physicians frequently request that additional tests be performed on an existing specimen (add-ons). In our institution, add-ons comprise approximately 1% of the specimen volume and require a disproportionate number of employees. Not only are add-on tests time-consuming and expensive, but storing routine specimens for 7 days in anticipation of add-ons consumes valuable laboratory space. Design.—One hundred sixty add-on tests during a 1-week period were reviewed. Objectives.—To analyze the pattern of add-on testing and determine methods to improve laboratory operations. Results.—All add-on tests were ordered within 24 hours of receipt of the original specimen, even though specimens were retained for 7 days. At our institution, 1.5 full-time equivalents are required to complete add-on testing, which accounts for less than 1% of the specimen volume. The most common add-on tests recorded during the study period were hepatic and electrolyte/renal/glucose panels. The medicine service ordered more than 60% of the add-on tests. Five percent of add-on tests were caused by a lack of order communication, 64.7% of cardiac marker add-ons were not ordered according to the chest pain protocol, and certain ordering patterns were present. Conclusions.—Routine specimens do not need to be retained for 7 days to accommodate add-on tests. Decreasing the storage time to 2 days would save space, while still maintaining regulatory compliance. Order communication with the laboratory, educating physicians about chest pain protocols, and instituting admission laboratory panels would decrease the number of add-ons in our hospital. This change would translate into a reduction in laboratory expenses and an improvement in operations.