Hospital laboratories frequently receive requests to add

Transcription

1 Evaluation of Add-on Testing in the Clinical Chemistry Laboratory of a Large Academic Medical Center Operational Considerations Stacy Foran Melanson, MD, PhD; Brian Hsieh; James G. Flood, PhD; Kent B. Lewandrowski, MD 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 Hospital laboratories frequently receive requests to add additional tests (add-ons) to an existing specimen. For this reason, among others, laboratories routinely save specimens after initial testing has been completed. 1 Performing add-on tests on stored specimens is time-consuming and costly. 2 In our hospital, laboratory add-on tests comprise approximately 1% of the daily specimen volume and consume 1.5 full-time equivalents per day. From the perspective of the laboratory operation, a technologist or assistant must answer the telephone call from the physician, record the information, find the specimen number in the computer, locate the specimen in a cold room filled with many test tube racks, and perform the requested test(s). 3 Decreasing the number of add-on tests could save significant labor resources. In addition, storing specimens in anticipation of possible add-ons uses expensive cold room or refrigerator space. The clinical chemistry laboratory at Massachusetts General Hospital retains specimens for 7 days in a 9.75-m 2 cold room. Analyzing the pattern and timing of add-ons Accepted for publication March 26, From the Division of Laboratory Medicine, Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston. The authors have no relevant financial interest in the products or companies described in this article. Reprints: Kent B. Lewandrowski, MD, Division of Laboratory Medicine, Massachusetts General Hospital, 55 Fruit St, GRJ 5, Boston, MA ( klewandrowski@partners.org). 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 addons 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. (Arch Pathol Lab Med. 2004;128: ) should provide information on how long specimens need to be stored to accommodate add-on testing. If laboratories can justify a decrease in retention time for routine specimens, space would be saved in storage areas. In this study, we evaluated approved add-on testing in our laboratory during a 1-week period. The time elapsed between receipt of the original specimen and the add-on test was recorded, along with the types of tests added and the test results. Add-ons performed on initial specimens, when the patient was first admitted, were also reviewed as a separate category. MATERIALS AND METHODS All approved add-on tests (n 160) performed during the week of June 1, 2003 to June 7, 2003 were reviewed. Add-on tests comprise 0.91% (116 add-ons per accessioned tests) of the daily test volume. In our institution, add-on tests are usually requested over the phone. A laboratory assistant or technologist completes an add-on form with the patient s name, medical record number, the specimen number(s) to which the tests will be added, the physician s name, the date and time of the call, the time the original specimen was received, and the add-on test(s) requested. The original requisition is retrieved and attached to the add-on form. We do not currently use inpatient electronic order communication in our hospital. We also conducted telephone interviews at 12 medical centers in the United States to determine the length of time that other laboratories retain routine chemistry specimens. The time that elapsed between receipt of the original specimen and the request for an add-on test was determined using the Arch Pathol Lab Med Vol 128, August 2004 Add-on Testing in a Clinical Chemistry Laboratory Melanson et al 885

2 Abbreviations for Add-on Tests Abbreviation Full Name Test Included CAPM Calcium, phosphorus, magnesium Calcium, magnesium, phosphorus Cardiac Cardiac markers Creatine phosphokinase, creatine kinase MB, troponin T CPK Creatine phosphokinase Creatine phosphokinase Endo Endocrine Thyroid-stimulating hormone, free T4, T3, cortisol, testosterone, vitamin D Fe/Fol/B 12 Anemia testing Iron, total iron-binding capacity, ferritin, folate, vitamin B 12 Fluid Fluid specimens Any routine test performed on a fluid specimen HEPP Hepatic panel Albumin, alkaline phosphatase, total and direct bilirubin, total protein, alanine aminotransferase, aspartate aminotransferase Ketone Ketone Ketones Lamy Lipase, amylase Lipase, amylase LDH Lactate dehydrogenase Lactate dehydrogenase LIPP Lipid panel Low-density lipoprotein, high-density lipoprotein, triglycerides, total cholesterol L/R/G Electrolytes/renal/glucose Sodium, potassium, chloride, carbon dioxide, serum urea nitrogen, creatinine, glucose Osm Osmolality Osmolality Ther Drug Therapeutic drugs Digoxin, dilantin, valproic acid, gentamicin, vancomycin, tegretol, cyclosporine Tumor Tumor markers Prostate-specific antigen, carcinoembryonic antigen, CA 125, CA 15-3, human chorionic gonadotropin Uric Uric acid Uric acid Urine Urine specimens Any routine test performed on a urine specimen times recorded on the add-on forms. Infrequently, times were not recorded on the form. On those cases, the accessioning and completion time were obtained from the laboratory information system. The laboratory information system was also used to determine whether the specimen was the first one drawn from the patient at admission. Both the original and add-on test were documented to characterize the type and distribution of add-on testing. Data regarding the requesting physician and/or service and the patient location (inpatient, emergency department, or outpatient) were recorded. Add-on tests were categorized into groups as follows (Table): (1) cardiac markers, including creatine phosphokinase (CPK), creatine kinase MB (CK-MB), and troponin T (TnT); (2) hepatic panel (HEPP), including albumin, alkaline phosphatase, total and direct bilirubin, total protein, alanine aminotransferase (ALT), and aspartate aminotransferase (AST); (3) electrolytes/renal/glucose (L/R/G), including sodium, potassium, chloride, carbon dioxide, serum urea nitrogen, creatinine, and glucose; (4) calcium/magnesium/phosphorus (CAPM); (5) lipase and amylase (Lamy); (6) lactate dehydrogenase (LDH); (7) CPK; (8) endocrine and thyroid tests; (9) therapeutic drug levels; (10) lipid panel, including low-density lipoprotein, high-density lipoprotein, triglycerides, and total cholesterol; (11) uric acid; (12) tumor markers; (13) osmolality; (14) iron/folate/b 12, including iron, total iron-binding capacity, ferritin, folate, and vitamin B 12 ; (15) ketones; (16) urine specimens; and (17) fluid specimens. The results of the add-on tests were obtained from the laboratory information system. RESULTS Of the approved add-on tests recorded, 60.6% were requested less than 4 hours and 89.4% were requested less than 8 hours from the time the original specimen was received. The longest time that elapsed between receipt of the original specimen and the add-on was 18.6 hours. Therefore, laboratory personnel only retrieved specimens less than 1 day old from the cold room to perform addon testing. The clinical chemistry laboratory at Massachusetts General Hospital stores routine specimens for 7 days in a m 2 cold room. The historical reason for this time limit was based on arbitrary precedent. To assess the current standard of practice, we performed a telephone survey at 12 prominent teaching hospitals throughout the United States. Among these institutions, the average retention time for routine chemistry specimens is days (7 for7days,1for6days,2for5days,1for4days,and1 for 1 day). These times vary slightly, depending on the workload. The storage time at Massachusetts General Hospital is within the range of the other hospitals, but longer than average. One hundred sixty add-on tests were performed between June 1, 2003 and June 7, The overwhelming majority of add-ons were routine chemistry tests, as opposed to esoteric assays (Figure, solid bars). The most common add-on tests were HEPP (20%), L/R/G (15.6%), CAPM (13.8%), and cardiac markers (10.6%). In all, 1.9% of the add-on tests requested had already been performed on the specimen, and 3.1% had been requested originally, but the laboratory did not perform the test. The patterns of add-on tests were examined to analyze the relationship between the add-on and the original order and to determine which physicians and/or services contributed the most to add-on testing. Of the markers for acute coronary syndrome, 64.7% were not ordered according to the hospital chest pain protocol (CK-MB and TnT on admission, and TnT at 2 time points thereafter). A total of 23.5% of physicians ordered CK-MB initially, only to add TnT as an afterthought. Another 35.3% added CK-MB and CPK, but neglected to order TnT. In the remaining 5.9%, CK-MB was added after TnT. Regarding electrolytes, 72.7% of CAPM add-ons were added to an existing L/R/G order, while 60% of L/R/G add-ons were added to a CAPM order or to complete an L/R/G panel. For hepatic and pancreatic assays, 60% of Lamy add-ons were added to HEPP, while 25% of HEPP requests were added to Lamy or partial HEPP. A total of 69.8% of add-on tests were performed on inpatient specimens, while the emergency department accounted for 18.9% and outpatients for 11.3%. In 25.6% of 886 Arch Pathol Lab Med Vol 128, August 2004 Add-on Testing in a Clinical Chemistry Laboratory Melanson et al

3 Distribution of add-on tests. Shown is the frequency of add-on tests requested on all samples (solid bars), first-draw samples (diagonally lined bars), and non first-draw samples (dotted bars). cases, the physician name was not available on the requisition. No single physician was responsible for an excess number of add-ons. Only 9.2% of physicians had more than 1 add-on, with the largest number being 3. On 42.5% of the forms, the requesting service was not available. From the remaining data, it was determined that add-ons were requested by a variety of services, including medicine (63.2%), surgery (10.2%), and neurology (7.4%). A total of 15.6% of add-ons were requested on the firstdrawn specimens. The add-ons requested on the firstdrawn samples (Figure, diagonally lined bars) on admitted patients had a slightly different pattern of distribution compared to non first-draw samples (Figure, dotted bars) and all add-ons (Figure, solid bars). Lactate dehydrogenase and Lamy accounted for 24% and 20% of first-draw add-ons, respectively, while endocrine tests, cardiac markers, and uric acid each accounted for 16%. Sixty percent of Lamy add-ons were added to HEPP. The results of each add-on were gathered from the laboratory information system. If any of requested add-ons for that sample were out of the reference range, the results were considered abnormal. Of the add-on tests requested on first-draw samples, 29.4% had at least 1 abnormal result. On the other hand, 63.3% of add-ons done on specimens other than first draws had abnormal values. When all add-ons were analyzed, 52.5% had 1 or more results out of the reference range. COMMENT To our knowledge, this is the first article to describe patterns of add-on tests in a large hospital laboratory and to assess the opportunity to decrease the number of addons and reduce labor expenses. All add-on tests during a 1-week period were requested within 24 hours of receipt of the original specimen, with most occurring in less than 8 hours. Various reasons account for add-on requests. Physicians may have neglected to order a test, or after receiving the results from the original order, they required new tests to determine diagnosis or management. Most patients (69.8%) for whom add-ons are requested are inpatients. Many of these patients receive daily blood draws, so additional tests after 8 to 12 hours may be able to wait until the next blood draw. Clinician input on the reasons for ordering add-on tests would be helpful for analysis. In our laboratory, we also impose time limits for adding certain tests that are unstable or otherwise are invalid after a fixed time in specimen storage. For example, certain tests cannot be added at any time, such as total carbon dioxide or tests that require the specimen to be frozen immediately. 4 The Joint Commission on Accreditation of Healthcare Organizations (JCAHO) and the College of American Pathologists require that routine clinical laboratory specimens be kept for 48 hours. In contrast, the Massachusetts Department of Public Health imposes no requirement regarding the retention of routine laboratory specimens. Our chemistry laboratory stores specimens for 7 days, despite the fact that our data show that all add-on tests are performed on specimens less than 1 day old. This suggests that specimens may not need to be stored for 7 days to accommodate add-on tests or to comply with laboratory regulations. Our laboratory includes a 9.75-m 2 storage area to hold specimens on which testing has been completed. If the number of specimens were reduced, space would become available for other purposes. For example, by using the JCAHO standard of 2 days for specimen retention, we could reduce cold room storage by 6.97 m 2.To assess the advisability of implementing this change, we conducted telephone interviews with chemistry laboratories at 12 academic medical centers across the United States to define the standard of practice. The survey showed that the average storage time for routine specimens is days. Clearly, given the range of 3.9 to 7.7 days, there is no generally accepted standard. Appar- Arch Pathol Lab Med Vol 128, August 2004 Add-on Testing in a Clinical Chemistry Laboratory Melanson et al 887

4 ently the storage time for chemistry specimens can be significantly reduced in most hospital laboratories and still accommodate add-on testing. Laboratories may have other reasons for retaining patient samples for longer periods of time. These reasons include verifying that the specimen was assigned to the correct patient, repeating questionable values, performing research protocols, or simply following precedent. Individual laboratories should consider all reasons for specimen storage, including add-ons, to define the storage time that is most appropriate for their institution. Reducing the number of add-ons that are requested could save resources spent on laboratory personnel that provide this service. In our laboratory, 1.5 full-time equivalents are required to accommodate add-on tests, although these only account for 0.91% of accessioned samples. A total of 18 full-time equivalents in 24 hours process the remaining 99.1% of received specimens. As would be expected, laboratory personnel performing add-on tests are 6 to 12 times less efficient and accomplish a significantly lower percentage of the workload. In terms of labor savings, every add-on test eliminated permits 6 to 12 routine tests to be performed. Most physician requests for add-on tests are for routine chemistry tests, such as cardiac markers, HEPP, L/R/G, CAPM, and Lamy, which can be done in-house. Add-on requests for esoteric tests are relatively uncommon. Of the add-on tests we recorded, 1.9% had already been performed by the laboratory, and 3.1% had been requested but had not been performed initially by the laboratory. This implies that approximately 5% of add-ons could be eliminated by improving communication with physicians and by using electronic provider order entry with order communication in the laboratory. An additional 10% of add-ons are performed more than 8 hours from the initial blood draw. Some of these tests could be avoided by requiring a new phlebotomy sample to be drawn after 8 hours for selected tests. Of the add-on tests we recorded, 10.6% were for cardiac markers, which are presumably ordered to determine the likelihood of an acute coronary syndrome. Of the markers for acute coronary syndrome, 64.7% were not ordered according to the hospital chest pain protocol (CK-MB and TnT on admission, and TnT at 2 time points thereafter). Cardiac troponin (TnT or TnI) is the accepted gold standard for diagnosing myocardial necrosis. 5 Patients presenting to our emergency department with suspected acute coronary syndromes receive CK-MB and troponin testing at the point of care. This suggests that areas other than the emergency department are responsible for the mistakes and do not always follow the protocol. Further investigation into those clinicians, such as house staff, who are not aware of the protocol may be warranted. Most add-ons for cardiac markers could be eliminated by educating physicians to use the chest pain protocol. For example, a house staff orientation may improve the ordering of cardiac markers as well as other laboratory tests. In this study, CPK or LDH alone were not considered cardiac markers because they are not typically used alone to evaluate patients with suspected acute coronary syndrome. Creatine phosphokinase is frequently ordered in patients with myopathy (including myopathy due to statins) and a variety of other disorders, while LDH is useful to evaluate hemolysis. Certain patterns can be seen when physicians order additional tests. The laboratory may be able to anticipate add-on tests by evaluating the original order. Add-ons may potentially be reduced by expanding test panels. For example, CAPM could be included with L/R/G, or Lamy could be incorporated into the HEPP. In certain situations, standard laboratory orders could be formulated. The costeffectiveness of altering laboratory test panels to prevent add-ons warrants further investigation, as does the problem of making standard panels compatible with medicare reimbursement guidelines. However, it is clear that reconfiguring test panels would have a major impact on addon testing and that significant labor savings would be possible. Clinical care might also benefit, because add-on testing is presumably necessary for patient diagnosis/treatment and having commonly requested add-on tests up front might expedite this process. A total of 15.6% of add-on tests are requested on the first sample drawn from the patient on admission. Tests for LDH accounted for the majority (24%) of first-draw add-ons. Developing admitting protocols that correspond to common diagnoses would decrease the number of addon tests and possibly expedite care. However, the value of LDH as an add-on in settings other than suspected hemolysis is questionable. Efforts should be directed toward physician and house-staff education and utilization control using an order entry pop-up screen or telephone consultation. A total of 69.8% of add-ons are done on inpatient samples, consistent with the patient population seen at our hospital. Add-on tests are requested by many physicians, and no subset could be singled out as a frequent offender. However, a disproportionate number of add-ons recorded in this study were requested by the medicine service (63.2% of add-on tests). Physician education efforts targeting the medical teams that are responsible for the majority of add-on tests may be beneficial in reducing the number of add-ons. The results of all add-on tests were recorded. Just more than half (52.5%) of the add-on samples had 1 or more abnormal results; however, the distribution was skewed. Initial blood draws are sometimes used to rule out less likely diagnoses, for which negative results are expected. This may explain the relatively low percentage of abnormal results on first draws. In addition, inpatients receiving multiple blood draws will typically have more complex medical problems, which contribute significantly to abnormal results. The relevance of add-on results to patient outcome should be examined and discussed with clinicians. Several opportunities to decrease add-on testing have been identified. Physician order entry with order communication to the laboratory would immediately reduce add-on testing by up to 5%. Adherence to a standardized chest pain protocol would eliminate 64.7% of cardiac marker add-ons (6.9% of total add-on tests). Denying addons after 8 hours would eliminate 10% of tests. Reconfiguring admitting laboratory orders or encouraging physicians to order extended panels up front would avoid many add-on tests, although the cost-effectiveness of this proposal needs further investigation. To our knowledge, this article is the first to describe and examine add-on testing and consider mechanisms to improve laboratory operations in a large hospital laboratory. 888 Arch Pathol Lab Med Vol 128, August 2004 Add-on Testing in a Clinical Chemistry Laboratory Melanson et al

5 References 1. Okorodudu AO, Elghetany MT. Specimen transport, logistics and processing. In: Lewandrowski K, ed. Clinical Chemistry: Laboratory Management and Clinical Correlations. New York, NY: Lippincott Williams & Wilkins; 2002: Weiss RL, Ash KO. Laboratory management. In: Burtis CA, Ashwood ER, eds. Tietz Textbook of Clinical Chemistry. 3rd ed. Philadelphia, Pa: WB Saunders Co; 1999: Ciment PR. Operations analysis, reengineering and process improvement. In: Lewandrowski K, ed. Clinical Chemistry: Laboratory Management and Clinical correlations. New York, NY: Lippincott Williams & Wilkins; 2002: Young DS, Berns EW. Specimen collection and processing: sources of biological variation. In: Burtis CA, Ashwood ER, eds. Tietz Textbook of Clinical Chemistry. 3rd ed. Philadelphia, Pa: WB Saunders Co; 1999: Wu AHB, Apple FS, Gibler WB, Jesse RL, Warshaw MM, Valdes R. National Academy of Clinical Biochemistry Standards of Laboratory Practice: recommendations for the use of cardiac markers in coronary artery disease. Clin Chem. 1999;45: Arch Pathol Lab Med Vol 128, August 2004 Add-on Testing in a Clinical Chemistry Laboratory Melanson et al 889