Benefits of costing in the clinical laboratory

Examining the utility of extended laboratory panel testing in the emergency department for risk stratification of patients with COVID-19: a single-centre retrospective service evaluation

BACKGROUND

The role of specific blood tests to predict poor prognosis in patients admitted with infection from SARS-CoV-2 remains uncertain. During the first wave of the global pandemic, an extended laboratory testing panel was integrated into the local pathway to guide triage and healthcare resource utilisation for emergency admissions. We conducted a retrospective service evaluation to determine the utility of extended tests (D-dimer, ferritin, high-sensitivity troponin I, lactate dehydrogenase and procalcitonin) compared with the core panel (full blood count, urea and electrolytes, liver function tests and C reactive protein).

METHODS

Clinical outcomes for adult patients with laboratory-confirmed COVID-19 admitted between 17 March and 30 June 2020 were extracted, alongside costs estimates for individual tests. Prognostic performance was assessed using multivariable logistic regression analysis with 28-day mortality used as the primary endpoint and a composite of 28-day intensive care escalation or mortality for secondary analysis.

RESULTS

From 13 500 emergency attendances, we identified 391 unique adults admitted with COVID-19. Of these, 113 died (29%) and 151 (39%) reached the composite endpoint. 'Core' test variables adjusted for age, gender and index of deprivation had a prognostic area under the curve of 0.79 (95% CI 0.67 to 0.91) for mortality and 0.70 (95% CI 0.56 to 0.84) for the composite endpoint. Addition of 'extended' test components did not improve on this.

CONCLUSION

Our findings suggest use of the extended laboratory testing panel to risk stratify community-acquired COVID-19 positive patients on admission adds limited prognostic value. We suggest laboratory requesting should be targeted to patients with specific clinical indications.

Selection of a cut-off for high- and low-methane producers using a spot-methane breath test: results from a large north American dataset of hydrogen, methane and carbon dioxide measurements in breath

BACKGROUND

Levels of breath methane, together with breath hydrogen, are determined by means of repeated collections of both, following ingestion of a carbohydrate substrate, at 15-20 minutes intervals, until 10 samples have been obtained. The frequent sampling is required to capture a rise of hydrogen emissions, which typically occur later in the test: in contrast, methane levels are typically elevated at baseline. If methane emissions represent the principal objective of the test, a spot methane test (i.e. a single-time-point sample taken after an overnight fast without administration of substrate) may be sufficient.

METHODS

We analysed 10-sample lactulose breath test data from 11 674 consecutive unique subjects who submitted samples to Commonwealth Laboratories (Salem, MA, USA) from sites in all of the states of the USA over a one-year period. The North American Consensus (NAC) guidelines criteria for breath testing served as a reference standard.

RESULTS

The overall prevalence of methane-positive subjects (by NAC criteria) was 20.4%, based on corrected methane results, and 18.9% based on raw data. In our USA dataset, the optimal cut-off level to maximize sensitivity and specificity was ≥4 ppm CH4, 94.5% [confidential interval (CI): 93.5-95.4%] and 95.0% (CI: 94.6-95.5%), respectively. The use of a correction factor (CF) (5% CO2 as numerator) led to reclassifications CH4-high to CH4-low in 0.7 % and CH4-low to CH4-high in 2.1%.

CONCLUSIONS

A cut-off value for methane at baseline of either ≥4 ppm, as in our USA dataset, or ≥ 5 ppm, as described in a single institution study, are both highly accurate in identifying subjects at baseline that would be diagnosed as 'methane-positive' in a 10-sample lactulose breath test for small intestinal bacterial overgrowth.

The Role of the Laboratory in Control of Nosocomial Infection

Nosocomial (hospital-associated) infection continues to represent a major problem for hospitals. Gram-negative aerobic bacilli continue to be identified most frequently as etiologic agents, but a number of new pathogens now are recognized to play a role. The persons responsible for infection control efforts and in charge of the clinical microbiology laboratory (frequently the same person) must cooperate closely to attack this problem. The role of the laboratory in attempts to minimize occurrence of nosocomial infection involves six aspects: 1) accurate identification of responsible organisms, 2) timely reporting of laboratory data, 3) provision of additional studies, when necessary, to establish similarity or difference of organisms, 4) provision, on occasion, of microbiologic studies of the hospital environment, 5) training of infection control personnel, and 6) participation in activities of the hospital infection control committee.

Cost effectiveness of adopted quality requirements in hospital laboratories

BACKGROUND

The present study was designed in quasi-experiment to assess adoption of the essential clauses of particular clinical laboratory quality management requirements based on international organization for standardization (ISO 15189) in hospital laboratories and to evaluate the cost effectiveness of compliance to ISO 15189.

METHODS

The quality management intervention based on ISO 15189 was conceded through three phases; pre - intervention phase, Intervention phase and Post-intervention phase.

RESULTS

In pre-intervention phase the compliance to ISO 15189 was 49% for study group vs. 47% for control group with P value 0.48, while the post intervention results displayed 54% vs. 79% for study group and control group respectively in compliance to ISO 15189 and statistically significant difference (P value 0.00) with effect size (Cohen's d) of (0.00) in pre-intervention phase and (0.99) in post - intervention phase. The annual average cost per-test for the study group and control group was 1.80 ± 0.25 vs. 1.97 ± 0.39, respectively with P value 0.39 whereas the post-intervention results showed that the annual average total costs per-test for study group and control group was 1.57 ± 0.23 vs 2.08 ± 0.38, P value 0.019 respectively, with cost-effectiveness ratio of (0.88) in pre -intervention phase and (0.52) in post-intervention phase.

CONCLUSION

The planned adoption of quality management requirements (QMS) in clinical laboratories had great effect to increase the compliance percent with quality management system requirement, raise the average total cost effectiveness, and improve the analytical process capability of the testing procedure.

Cost of gentamicin assays carried out by microbiology laboratories

AIMS

To assess the current range of prices charged for gentamicin assays in United Kingdom laboratories; and to examine the laboratories' likely response to increases or decreases in the demand for the service.

METHODS

A postal survey of the 420 members of the Association of Medical Microbiologists was used to establish the range of prices charged for aminoglycoside assays. Additionally, eight private institutions were contacted to determine what the private sector was charging for aminoglycoside assays. Reagent costs in the NHS laboratories were calculated by dividing the total cost of all aminoglycoside assay kits by the number of samples analysed.

RESULTS

The NHS and the private institutions both showed a wide price variation. Prices charged to an in-hospital requester for a peak and trough assay ranged from 5.00 pounds to 68.20 pounds (n = 44), and to an external private hospital, under a bulk service contract, from 5.00 pounds to 96.00 pounds (n = 47). Prices charged by private laboratories ranged from 49.00 pounds to 84.00 pounds (n = 8). There was a log linear correlation in the NHS laboratories between the reagent costs per assay and the number of assays performed per year, and most laboratories thought that their price per assay would be sensitive to increases or decreases in demand. Laboratories which had purchased their assay machines had lower reagent costs per assay but higher repair and maintenance costs. Overall, number of assays performed and method of payment for assay machinery only accounted for 44.8% of the observed variation in assay kit costs.

CONCLUSIONS

The price range for gentamicin assays in the United Kingdom is wide and is only partially explained by the number of assays performed. Most laboratories believe that they would experience a reduction in unit cost as output increases. The currently offered range of prices is, in part, due to variation in the laboratories' approach to costing the service provided and some laboratories charge prices which do not even cover the cost of assay kits. Overall, we believe that prices charged should be as close as possible to the marginal cost of the tests performed.

Use of multichannel discrete analyser to reduce unnecessary biochemical tests

AIM

To investigate the waste of laboratory reagents which resulted from the process of ordering biochemistry profiles.

METHODS

The frequency of measurement of 15 analytes was recorded during the six months before the introduction of a system of discretionary requesting and analysis of samples (high capacity multichannel discrete analyser), and also during the same six month period one year and two years after its introduction.

RESULTS

The frequency of measurement of 10 of the 15 analytes decreased during the six month period one year after the change to discretionary testing. The remaining five analytes were measured up to 22% more frequently. There was an overall decrease in the measurement of biochemical tests by 31,359. This created an annual cost saving of 7124 pounds. In the second year five analytes still continued to be measured less frequently than originally but the remaining 10 analytes were measured more frequently. This resulted in an overall increase in the measurement of biochemical tests by 53,678 compared with the six month period before discretionary analysis. The pattern of requests was similar during both periods of discretionary requesting studied and as a result, a small annual cost saving of 1672 pounds was again made.

CONCLUSION

Discretionary requesting and analysis of tests may eliminate the measurement of clinically unnecessary test which had previously resulted from the processes of ordering tests. These cost savings may be rapidly eroded by an increase in the laboratory workload.

Guidelines (1988) for training in clinical laboratory management. International Federation of Clinical Chemistry (IFCC) Education Division and International Union of Pure and Applied Chemistry (IUPAC) Clinical Chemistry Division Commission on Teaching of Clinical Chemistry

Trainees in laboratory medicine must develop skills in laboratory management. Guidelines are detailed for laboratory staff in training, directors responsible for staff development and professional bodies wishing to generate material appropriate to their needs. The syllabus delineates the knowledge base required and includes laboratory planning and organisation, control of operations, methodology and instrumentation, data management and statistics, financial management, clinical use of tests, communication, personnel management and training, and research and development. Methods for achievement of the skills required are suggested. A bibliography of IFCC publications and other material is provided to assist in training in laboratory management.

Microcomputer software to facilitate costing in pathology laboratories

A software program is described which will enable laboratory managers to calculate, for their laboratory over a 12 month period, the cost of each test or investigation and of components of that cost. These comprise the costs of direct labour, consumables, equipment maintenance and depreciation; allocated costs of intermediate operations--for example, specimen procurement, reception, and data processing; and apportioned indirect costs such as senior staff time as well as external overheads such as telephone charges, rent, and rates. Total annual expenditure on each type of test is also calculated. The principles on which the program is based are discussed. Considered in particular, are the problems of apportioning indirect costs (which are considerable in clinical laboratory work) over different test costs, and the merits of different ways of estimating the amount or fraction of staff members' time spent on each kind of test. The computer program is Crown copyright but is available under licence from one of us (JAS).

Strategies to modify the test-requesting patterns of clinicians

Studies of the effectiveness of various strategies for influencing clinicians' test-requesting behaviour are reviewed. Numerical rationing, although crude, effectively reduces unnecessary repeat testing without detriment to patient outcome. Educational programmes involving peer review show pronounced but short-lived effects. Simple feedback of information about numbers of tests requested and their costs is surprisingly ineffectual. Direct financial incentives, in a private health care system, also failed. Clinical budgeting, of benefit in experimental trials, has yet to be widely tested, and the savings on reducing laboratory requesting may not be large enough to be attractive to clinicians. Agreed requesting policies in various specialties and clinical circumstances, endorsed by senior clinicians and prestigious professional bodies, seems a promising approach to more appropriate test requesting; further objective studies of their long-term effects are needed. Redesign of request forms into a problem-orientated format may be the simplest and most effective contribution by the laboratory; this strategy deserves further critical appraisal.

Histopathology in tropical medicine: a perspective

Histopathology may serve a wide spectrum of diagnostic purposes in tropical medicine other than for infectious and parasitic diseases. In addition, it is essential in defining new pathological entities and collecting statistical data on morbidity and mortality. It should also constitute a basic support for advancement and research in tropical diseases. For practical purposes, both histopathology and cytopathology are often more effective than clinical chemistry and microbiology in providing the clinician with a final diagnosis. They do not rely on complicated and delicate equipment, and the few reagents they require can be stored indefinitely. Formalin fixation permits most histological methods to be used, including special stains and immunohistochemistry. Formalin-fixed material can be examined several days after excision. Implementing pathology laboratories in tropical countries may constitute a practical, cost-effective approach to the planning of diagnostic services at the regional or district level. A fraction of the medical graduates in developing countries should be devoted to the staffing of these laboratories.