Comparative Analytical Costs of Central Laboratory Glucose and Bedside Glucose Testing: A College of American Pathologists Q-Probes Study
Context.-One of the major attributes of laboratory testing is cost. Although fully automated central laboratory glucose testing and semiautomated bedside glucose testing (BGT) are performed at most institutions, rigorous determinations of interinstitutional comparative costs have not been performed.
Objectives.-To compare interinstitutional analytical costs of central laboratory glucose testing and BGT and to provide suggestions for improvement.
Design.-Participants completed a demographic form about their institutional glucose monitoring practices. They also collected information about the costs of central laboratory glucose testing, BGT at a high-volume testing site, and BGT at a low-volume testing site, including specified cost variables for labor, reagents, and instruments.
Participants.-A total of 445 institutions enrolled in the College of American Pathologists Q-Probes program.
Main Outcome Measure.-Median cost per glucose test at 3 testing sites.
Results.-The median (10th-90th percentile range) costs per glucose test were $1.18 ($5.59-$0.36), $1.96 ($9.51-$0.77), and $4.66 ($27.54-$1.02) for central laboratory, high-volume BGT sites, and low-volume BCT sites, respectively. The largest percentages of the cost per test were for labor (59.3%, 72.7%, and 85.8%), followed by supplies (27.2%, 27.3%, and 13.4%) and equipment (2.1%, 0.0%, and 0.0%) for the 3 sites, respectively. The median number of patient specimens per month at the high-volume BGT sites was 625 compared to 30 at the low-volume BGT sites. Most participants did not include labor, instrument maintenance, competency assessment, or oversight in their BGT estimated costs until required to do so for the study.
Conclusions.-Analytical costs per glucose test were lower for central laboratory glucose testing than for BGT, which, in turn, was highly variable and dependent on volume. Data that would be used for financial justification for BGT were widely aberrant and in need of improvement.
(Arch Pathol Lab Med. 2004;128:739-745)
Two of the most important characteristics of a successful justification for implementing new health care technologies are that medical care will be improved and that costs will be reduced. A successful justification is no different for clinical laboratory technologies, in which the outcomes and costs of a proposed technology are expected to demonstrate improvement in comparison with the current technology. During the past 20 years, laboratory medicine has undergone a major change with the implementation of point-of-care testing (POCT), which entails nonlaboratory personnel performing laboratory tests at patients' bedsides rather than having laboratory personnel perform these procedures in a central laboratory. Also, POCT usually is performed by personnel who manually or semiautomatically perform individual measurements, as compared to central laboratory testing, in which dedicated personnel perform high-throughput, fully automated testing. Currently, the most common POCT is performed for blood glucose determinations, and because this procedure currently is performed in most hospitals, it serves as a model for implementing other POCT.
The cost of bedside glucose testing (BGT) has been studied, but the medical literature on this topic is confusing, contradictory, highly variable, and frequently a matter of opinion. Zaloga1 found BGT less costly than clinical laboratory testing when used in an intensive care unit. In contrast, 6 different studies found central laboratory testing less costly than BGT.2-7 However, Lee-Lewandrowski and colleagues8 reported that in their institutions, BGT costs were higher than central laboratory glucose determinations in most situations; however, in some high-volume situations, BGT costs were lower. De Cresce and colleagues9 compared cost accounting among published studies and concluded that differences, in part, were due to unique institutional factors where the testing was performed, the sites and technologies that were compared, and the costs that were included or excluded in the cost comparisons.
Since 1989, the College of American Pathologists (CAP) has sponsored more than 100 voluntary Q-Probes quality improvement studies for anatomic and clinical pathology laboratories. We report the results of a recent Q-Probes study aimed at describing the comparative analytical costs of central laboratory glucose testing, a high-volume BGT, and a low-volume BGT site in a large number of institutions and provide recommendations for improvement.
MATERIALS AND METHODS
Participants enrolled in the CAP Q-Probes program participated in the study using the usual Q-Probes format.10 Practice variables were obtained from the yearly participant demographic form. Four input forms were required to be completed: one for general information, a second for the central laboratory, a third for a high-volume BGT site, and a fourth for a low-volume BGT site. The questionnaires for the 2 BGT sites were identical, and the input form for the central laboratory was nearly identical to those for the BGT sites, as it required consideration of additional consumable costs, such as pipette tips.
Although laboratory personnel completed the BGT input forms, discussions with BGT testing personnel were required to answer the questions about POCT. Inpatient nursing personnel identified a high-volume and a low-volume BGT site to enter into the study. Personnel at these testing sites collected BGT data for a month, including the number of patient specimens tested, repeated, or referred to the clinical laboratory, as well as the number of quality control (QC) specimens tested. All input forms were precoded to aid the accurate collection of numerical information, and costs were expressed in US dollars.
Participants collected data about their costs per test according to the following equations for each of the 3 sites. A full-time equivalent (FTE) was defined as an employee who worked 40 hours per week, personnel salaries included benefits, time spent for glucose testing included oversight and competency assessment, and QC included the cost of proficiency testing.
Central Laboratory Glucose Testing
Cost per Test = (Cost of Equipment + Supplies + Labor) ÷ (No. of Patient Glucose Specimens)
where Equipment Costs = [(No. of Instruments Leased)(Annual Lease Payment) + (No. of Instruments Purchased)(Purchase Price)/(Life Expectancy) + (No. of Yearly Maintenance Contracts)(Average Yearly Maintenance Cost)] [(No. of Glucose Measurements/Total No. of Measurements)]; Supply Costs = (Costs of Reagents + QC Materials + Consumables); and Labor Costs = (Median Salary of Primary Testing Personnel)(% Time Spent by Primary Personnel on Glucose Testing)(No. of Primary FTEs) + (Median Salary of Secondary Testing Personnel)(% Time Spent by Secondary Personnel on Glucose Testing)(No. of Secondary FTEs).
Bedside Glucose Testing
Cost per Test = (Cost of Equipment + Supplies + Labor) ÷ (No. of Patient BGT Specimens)
where Equipment Costs = [(No. of Instruments Leased)(Annual Lease Payment) + (No. of Instruments Purchased)(Purchase Price)/(Life Expectancy) + (No. of Yearly Maintenance Contracts)(Average Yearly Maintenance Cost)] [(No. of Glucose Measurements/Total No. of Measurements)]; Supply Costs = (Costs of Reagents + QC Materials + Consumables); and Labor Costs = (Median Salary of Primary Personnel)(% Time Spent by Primary Personnel on BGT Testing)(No. of Primary FTEs) + (Median Salary of Secondary Testing Personnel)(% Time Spent by Secondary Testing Personnel on BGT Testing)(No. of Secondary FTEs).
Participants were ranked by percentiles, with those with lowest costs defined as the highest percentiles and those with the highest costs defined as the lowest percentiles. When participants failed to answer a question, they were excluded from the data analysis for that question only. We tested the statistical significance of practice variables on the cost of glucose testing using the nonparametric Kruskal-Wallis and Wilcoxon tests and considered P
A total of 445 institutions submitted data for this study. Most (95.7%) were from the United States; the remainder were from Canada, the United Kingdom, Australia, Argentina, Saudi Arabia, and Spain. The Figure highlights some of the characteristics of participating institutions.
The calculated cost per glucose test was computed for individual institutions using their reported actual costs for equipment, supplies, and personnel, as seen in Table 1. Overall, the analytical cost per test for glucose testing was lowest in central laboratories, intermediate in high-volume BGT sites, and highest in low-volume BGT sites. Median costs per test were $1.18, $1.96, and $4.66 for central laboratory, high-volume BGT, and low-volume BGT sites, respectively. However, costs were highly variable among participants. Central laboratory glucose testing costs per test tended to be lower for teaching institutions (P = .03).