Use Of Laboratory Resources Research Articles

Revisiting the Environmental Impact of Inappropriate Clinical Laboratory Testing: A Comprehensive Overview of Sustainability, Economic, and Quality of Care Outcomes.

The use of laboratory resources has seen a substantial increase in recent years, driven by automation and emerging technologies. However, inappropriate use of laboratory testing, encompassing both overuse and underuse, poses significant challenges. This review explores the complex interplay between patient safety, economic, and environmental factors-known as the "triple bottom line" or "3Ps" for people, profit, and planet-associated with inappropriate use of laboratory resources. The first part of the review outlines the impact of inappropriate laboratory testing on patient safety and economic outcomes. Then the review examines the available literature on the environmental impact of laboratory activities. Several practical solutions for mitigating the environmental impact of laboratories are discussed. Finally, this review emphasizes how decreasing unnecessary laboratory testing results in cost savings and environmental benefits, as evidenced by interventional studies, without compromising patient safety. The implementation of sustainable practices in laboratories can create a virtuous circle in which reduced testing enhances cost-efficiency, reduces the environmental footprint, and ensures patient safety, thereby benefiting the 3Ps. This review highlights the critical need for appropriate laboratory resource utilization in achieving sustainability in healthcare.

Feasibility for rapid on-site screening of pesticide residues in fresh produce using machine learning-assisted diffuse reflectance spectroscopy

Ensuring food safety by minimizing pesticide residues in crops is crucial to safeguarding human health. However, farmers often fail to follow the minimal time interval known as the Pre-Harvest Interval (PHI) between pesticide application and crop harvest. This lapse leads to high pesticide residue levels, often exceeding the recommended maximum residue levels (MRLs). Conventional methods for detecting pesticide residues are laboratory-based and rely on complex wet chemistry procedures. Although highly accurate, these techniques are destructive, expensive, and time-consuming. In addition, they take several hours before establishing results, making them unsuitable for analyzing large volumes of perishable fresh produce, particularly in resource-constrained settings. In this study, we investigated the feasibility of utilizing machine learning-assisted diffuse reflectance spectroscopy (DRS), a direct, rapid, and cost-effective approach for conducting an on-site preliminary assessment of pesticide residue levels in fresh produce, referred to as “screening.” This method facilitates the validation of fresh produce compliance with crop-specific PHI requirements after pesticide application, indicating adherence to MRLs. We used a portable Vis/NIR spectrometer to acquire DRS measurements from tamarillo fruits that had just been sprayed with mancozeb at the cultivation site. In total, 646 measurements were collected from treated and control (untreated) fruits over five alternating days, covering the duration between pesticide application and PHI lapse. We used spectral data pre-processing techniques and principal component analysis (PCA) to differentiate the fruits as the residue levels decreased, approaching the recommended PHI and demonstrating their suitability for harvesting. Furthermore, using two principal components that explained 88% of the total variance, we developed a support vector machine (SVM) classification model. The model successfully classified both the treated and control samples, as well as the samples based on their PHI status, distinguishing between ‘before PHI’ (days 1 - 7), ‘after PHI’ (day 9), and ‘Control’ (no residues), all with 100% accuracy. Given the quick turnaround time for results, typically within five minutes, we conclude that DRS combined with machine learning holds the potential for rapid and cost-effective on-site screening of large volumes of fresh produce in a market setting. This approach allows for the rapid identification of samples that require additional investigation in a food safety laboratory, thereby improving the efficient use of laboratory resources.

EFLM Symposium - Inappropriate use of laboratory resources - Demand management tools and how to use them.

EFLM Symposium - Inappropriate use of laboratory resources - Demand management tools and how to use them.

Inappropriate and potentially avoidable emergency department visits of Swiss nursing home residents and their resource use: a retrospective chart-review

BackgroundEmergency department (ED) visits for nursing home residents lead to higher morbidity and mortality. Therefore, inappropriate visits (for conditions treatable elsewhere) or potentially avoidable visits (those avoidable through adequate chronic care management) must be minimized. This study aimed to investigate factors and resource consumption patterns associated with inappropriate and potentially avoidable visits in a Swiss tertiary hospital.MethodsThis is a single-center retrospective chart review in an urban Swiss university hospital ED. A consecutive sample of 1276 visits by nursing home residents (≥ 65 years old), recorded between January 1, 2015 and December 31, 2017 (three calendar years) were included. Case characteristics were extracted from ED electronic documentation. Appropriateness was assessed via a structured Appropriateness Evaluation Protocol; potentially avoidable visits—measured as ambulatory-care sensitive conditions (ACSCs)—were analyzed separately. Inter-group differences concerning ED resource use were tested respectively with chi-square or Wilcoxon rank sum tests. To identify predictors of inappropriate or potentially-avoidable visits, we used multivariable logistic regression analysis.ResultsSix percent of visits were rated as inappropriate: they had lower triage levels (OR 0.55 [95%-CI 0.33-0.92], p=0.024) and, compared to ambulance calls, they had higher odds of initiation via either patient-initiated walk-in (OR 3.42 [95%-CI 1.79-6.55], p≤0.001) or GP referrals (OR 2.13 [95%-CI 1.16-3.90], p=0.015). For inappropriate visits, overall ED resource use was significantly lower (median 568 vs. 1403 tax points, p≤0.001). Of all visits included, 29% were due to (often potentially-avoidable) ACSCs. In those cases, compared to ambulance initiation, odds of being potentially-avoidable were considerably lower for walk-in patients (OR 0.46 [95%-CI 0.27-0.77], p=0.004) but higher for GP referrals (OR 1.40 [95%-CI 1.00-1.94], p=0.048). Nurse work (93 tax points vs. 64, p≤0.001) and laboratory resource use (334 tax points vs. 214, p≤0.001) were higher for potentially-avoidable ED visits.ConclusionsWe revealed substantial differences between the investigated groups. While nearly one third of ED visits from nursing homes were potentially avoidable, inappropriate visits were lower in numbers and not resource-intensive. Further research is required to differentiate potentially avoidable visits from inappropriate ones and to determine these findings’ public health implications.

Clinical, Methodological, and Practical Considerations for Algorithmic Testing in Autoimmune Serology.

Autoimmune serology tests are central to the classification, screening, diagnosis, and monitoring of a variety of autoimmune disorders. To improve the appropriateness of serologic evaluation and support laboratory resource utilization, reflex testing approaches have been proposed and implemented across clinical laboratories. Reflex testing involves a staged approach where an initial test result triggers subsequent tests based on prespecified rules. Various reflex testing approaches in the context of antinuclear antibody-associated rheumatic disease, antineutrophil cytoplasmic autoantibody-associated vasculitis, celiac disease, and myasthenia gravis are reviewed here. Clinical, analytical, and practical considerations of reflex testing implementation are addressed as well as associated limitations and challenges. Serology reflex testing algorithms for the evaluation of autoimmune diseases can support clinical diagnosis and laboratory resource use but may be challenging to implement and are often applied variably across institutions. Assessments of evidence-driven guidelines, clinical impact, and impact on laboratory workflow are essential to this task.

Anti-Methanogenic Effect of Phytochemicals on Methyl-Coenzyme M Reductase—Potential: In Silico and Molecular Docking Studies for Environmental Protection

Methane is a greenhouse gas which poses a great threat to life on earth as its emissions directly contribute to global warming and methane has a 28-fold higher warming potential over that of carbon dioxide. Ruminants have been identified as a major source of methane emission as a result of methanogenesis by their respective gut microbiomes. Various plants produce highly bioactive compounds which can be investigated to find a potential inhibitor of methyl-coenzyme M reductase (the target protein for methanogenesis). To speed up the process and to limit the use of laboratory resources, the present study uses an in-silico molecular docking approach to explore the anti-methanogenic properties of phytochemicals from Cymbopogon citratus, Origanum vulgare, Lavandula officinalis, Cinnamomum zeylanicum, Piper betle, Cuminum cyminum, Ocimum gratissimum, Salvia sclarea, Allium sativum, Rosmarinus officinalis and Thymus vulgaris. A total of 168 compounds from 11 plants were virtually screened. Finally, 25 scrutinized compounds were evaluated against methyl-coenzyme M reductase (MCR) protein using the AutoDock 4.0 program. In conclusion, the study identified 21 out of 25 compounds against inhibition of the MCR protein. Particularly, five compounds: rosmarinic acid (−10.71 kcal/mol), biotin (−9.38 kcal/mol), α-cadinol (−8.16 kcal/mol), (3R,3aS,6R,6aR)-3-(2H-1,3-benzodioxol-4-yl)-6-(2H-1,3-benzodioxol-5-yl)-hexahydrofuro[3,4-c]furan-1-one (−12.21 kcal/mol), and 2,4,7,9-tetramethyl-5decyn4,7diol (−9.02 kcal/mol) showed higher binding energy towards the MCR protein. In turn, these compounds have potential utility as rumen methanogenic inhibitors in the proposed methane inhibitor program. Ultimately, molecular dynamics simulations of rosmarinic acid and (3R,3aS,6R,6aR)-3-(2H-1,3-benzodioxol-4-yl)-6-(2H-1,3-benzodioxol-5-yl)-hexahydrofuro[3,4-c]furan-1-one yielded the best possible interaction and stability with the active site of 5A8K protein for 20 ns.

Engaging Laboratory Staff in Stewardship: Barriers Experienced by Medical Laboratory Technologists in Canada.

Laboratory stewardship programs aim to improve the use of laboratory resources, including reducing inappropriate testing. These programs should engage all healthcare stakeholder groups, including all levels of laboratory staff. Medical laboratory technologists (MLTs) are highly skilled professionals and are well positioned to play a supportive role in stewardship but may be overlooked. The aim of this study is to identify the barriers to MLT participation in stewardship activities. We developed and disseminated a self-administered survey to MLTs in Canada to assess their knowledge and attitudes toward inappropriate laboratory utilizatioz and explore perceived barriers to taking on an active role in stewardship initiatives. Themes were identified in open-ended responses and mapped to the Theoretical Domains Framework (TDF). MLTs feel accountable for helping ensure appropriate resource use and recognize that it is an important issue to address. However, they experience significant barriers and have low intention to act. The self-reported barrier most frequently described was lack of time arising from excessive workloads, but other constraints exist. Themes mapped to the TDF most strongly in the domain of environmental context and resources, supporting evidence that workplace structure and culture play key roles in impacting this group. To meaningfully engage MLTs in stewardship activities, these barriers should be addressed. Highlighting MLT expertise and creating communication structures and opportunities for their unique contributions may be fruitful.

Inappropriate use of laboratory tests: How availability triggers demand – Examples across Europe

IntroductionThe appropriate use of laboratory diagnostics is increasingly at stake. The aim of this study was to depict some paradigmatic examples of under- and overutilization, as well as possible solutions across Europe. MethodsWe collected six examples from five European countries where a rise or decline of orders for specific laboratory parameters was observed after organizational changes but without evidence of changes in patient collective characteristics as source of this variation. ResultsThe collected examples were the following: 1-Germany) Switch from a Brain-Natriuretic-Peptide assay to NT-pro Brain-Natriuretic-Peptide assay, resulting in a 374% increase in these analytics; 2-Spain) Implementation of a gatekeeping strategy in tumor marker diagnostics, resulting in a 15–61% reduction of these diagnostics; 3-Croatia) Stepwise elimination of creatine-kinase-MB assay from the laboratory portfolio; 4-UK) Removal of γ-glutamyl transferase from a “liver function” profile, resulting in 82% reduction of orders; 5-Austria) Implementation of a new device for rapid Influenza-RNA detection, resulting in a 450% increase of Influenza testing; 6-Spain) Insourcing of 1,25-(OH)2-Vitamin D measurements, leading to a 378% increase of these analyses. ConclusionThe six paradigmatic examples described in this manuscript show that availability of laboratory resources may considerably catalyze the demand, thus underscoring that inappropriate use of laboratory resources may be commonplace in routine laboratories all across Europe and most probably beyond. They also demonstrate that the application of simple strategies may assist in overcoming this issue. We believe that laboratory specialists need to refocus on the extra-analytical parts of the testing process and engage more in interdisciplinary patient-care.

An Experiment Resource Reservation Strategy Based on Rigid Demand and Reputation

With the increasing investment in teaching and scientific research, universities have established high-level experimental teaching centers. In order to make full use of laboratory equipment resources, more and more laboratories have established an open sharing system. However, due to the outstanding problems such as the large number of students, the wide range of majors, the small number of full-time experimental personnel, and the long time opening, there are inevitably some scrambles and sometimes vacancy in the process of opening and sharing, so the experimental resources cannot be used with the maximum efficiency. Based on the traditional time priority reservation strategy, it comprehensively considers the reputation problems caused by breaking the reservation and canceling the reservation, as well as the resource demand weight near the course acceptance, and proposes a multi parameter laboratory resource reservation strategy based on rigid demand and reputation. It uses convenient and fast information technology to balance the density of resource occupation, to achieve a fair and reasonable optimization of reservation strategy, so as to improve the efficiency of laboratory resource use and the quality of practical teaching.

Prolonged APTT of unknown etiology: A systematic evaluation of causes and laboratory resource use in an outpatient hemostasis academic unit

BackgroundA prolonged activated partial thromboplastin time (APTT) of unknown cause is one of the most frequent reasons why outpatients are referred for hemostasis consultation. Nevertheless, very few data are available on the relative contribution of individual causes of this common clinical scenario. Here, we present a systematic evaluation of all causes of APTT prolongation in a consecutive population of outpatients referred for specialized hemostasis consultation during a 14‐year period. MethodsAll cases referred to an academic specialized hemostasis outpatient unit due to APTT prolongation of unknown etiology whose prolonged APTT was confirmed in the first visit were included in the study. Data were obtained from the electronic medical records. ResultsAmong 187 consecutive patients, the most frequent causes were antiphospholipid antibodies in 22.6%, contact pathway factor deficiencies in 17.4%, other coagulation factor deficiencies in 11.6%, and vitamin K deficiency/liver disease in 11.6%. A definite cause was not identified in 22.1% of patients. Presence of antiphospholipid antibodies, and absence of bleeding symptoms were both associated with significantly longer APTT values compared to other categories/clinical scenarios. The investigation of each case required a mean of 18.2 additional tests per patient, with estimated costs ranging from US$191.60 to US$1055.60. ConclusionsOur results describe the main causes of APTT prolongation in outpatients, as well as estimates of resource use required to investigate this condition, thus providing evidence supporting the importance of measures to minimize the indiscriminate use of this assay.

528. Lab Stewardship for Clostridium difficile Testing Improves Appropriate Testing While Decreases Unnecessary Testing and Saves Laboratory Resources While Dramatically Helping to Reduce C diff Standardized Infection Ratios (SIR)

BackgroundUnnecessary testing for Clostridium difficile infection (CDI) can be both wasteful and contra productive—retesting the same positive patient after transfer to a new nursing unit will only to confirm the patient has CDI (already known) and likely be classified as a new case of hospital-onset (HO) CDI. Yet, it is also important to recognize community-onset (CO) CDI in hospital, not only because it prevents late recognition of CO CDI as being classified as an HO event, will also to afford appropriate contact precautions and therapeutic measures are instituted in a timely fashion. Laboratory stewardship (LS) can be helpful in improving appropriateness of C. difficile testing.MethodsWe developed 2 CDI testing algorithms. One focused on hospital days 1–3, the other for all C. difficile testing after hospital day 3 (AHD3). The LS quality improvement (QI) project was rolled out in 2 stages. During the first 6 months we focused on improving early detection of CO-CDI, while during the next 6 months a mandatory review of all C. difficile testing orders AHD3 was conducted by a 10 person team. Testing that concurred with the algorithm was approved. Nonapproval was communicated to the care teams. Appeals could be made on a case-by-case basis to the medical director of infection control. Validation audits of nonapproved cases were performed to determine whether testing algorithms were sound.ResultsCO-CDI detection steadily increased over the yearlong LS QI period (average of 6 cases/week at start vs. 12 cases/week at year’s end). During the 6 months of the AHD3 mandatory order review 678 C. difficile orders were placed, 428 (63.1%) were approved, 250 (36.9%) were rejected. Reduced use of laboratory resources is estimated to have saved $14,950. LS and frequent communication with care teams contributed better recognition of CO-CDI, decreased inappropriate repeat testing, avoidance of diagnosing colonized patients as HO-CDI and was associated with a significantly drop our CDI SIR (Figure 1).ConclusionAn algorithm-based guideline for a 2-step LS QI program focused on reviews of all C. difficile orders AFHD3 as well as improving early detection of CO-CDI and was associated with better laboratory resource utilization and markedly decreased C. difficile SIR. Efforts are currently underway to automate much of the review process. Disclosures J. P. Parada, Merck: Speaker’s Bureau, Speaker honorarium. A. Harrington, Biofire: Grant Investigator and Scientific Advisor, Consulting fee, Research grant and Speaker honorarium. Cepheid: Grant Investigator and Speaker’s Bureau, Research grant.

229. The Role of Antimicrobial Stewardship Program on Appropriate Use, Dose, and Duration of Vancomycin Treatment

BackgroundIn an era of increasing bacterial resistance, antimicrobial stewardship programs (ASP) are essential in guiding judicious antibiotic use and improving patient safety goals. A prior medication use evaluation of vancomycin conducted at Stony Brook University Hospital (SBUH) identified three areas for improvement: (1) vancomycin dosing to achieve target trough concentration, (2) treatment duration, (3) and the use of vancomycin drug assay. As a result, the ASP at SBUH implemented an interdisciplinary team which consists of pharmacists and physicians to optimize these areas.MethodsA prospective quality improvement program was implemented from October 1, 2017 to December 31, 2017. Patients on two medicine units (60 patient beds) were enrolled in the program if they received vancomycin for more than one day and were not on hemodialysis. The ASP monitored for appropriate use of vancomycin as well as providing real-time guidance on dosing and serum concentration monitoring. If vancomycin was not indicated or de-escalation was warranted, the physician was contacted for discontinuation or de-escalation. To evaluate the impact of the program, we selected comparable patients from two other medicine units during the same period as the control group. Duration of vancomycin therapy, the percentage of patients achieving target trough level and 24-hour AUC within 72 hours, and use of vancomycin drug assay were compared.ResultsThere were 84 patients in the intervention group and 142 patients in the control group with similar age, weight, and creatinine clearance. The intervention group achieved a 20% reduction in the days of vancomycin use (median days of therapy 4.55 vs. 5.7 days, P = 0.071), a higher percentage of patient achieving trough level of 10–20 μg/mL (80.65% vs. 51.79%, P = 0.0001) and 24 hour AUC >400 mg hours/L (95.16% vs. 74.6%, P = 0.001), and a lower number of trough levels per course (1.51 vs. 2.54, P = 0.007). The 3-month medication cost savings from the program on these two units was over $6,000.ConclusionAn ASP supervised program led to a reduction in vancomycin days of therapy, early attainment of optimal exposure, and decreased use of laboratory resources. Moreover, the program lowered the overall healthcare cost.Disclosures All authors: No reported disclosures.

Managing inappropriate utilization of laboratory resources.

Background The inappropriate use of laboratory resources, due to excessive number of tests not really necessary for patient care or by failure to order the appropriate diagnostic test, may lead to wrong, missed or delayed diagnosis, thus potentially jeopardizing patient safety. It is estimated that 5-95% of tests are currently used inappropriately, depending on the appropriateness criteria, thus significantly contributing to the potential of generating medical errors, the third leading cause of death in the US. Content In this review, we discuss the reasons as well as the medical and financial consequences of inappropriate utilization of laboratory tests. We then provide demand management (DM) tools as a means for overcoming this issue and also discuss their benefits, challenges, limitations and requirements for successful implementation. Summary and outlook When based on current evidence, adapted to local conditions and developed in close collaboration with clinicians, DM is a reasonable strategy for progressing toward better management of over- and underuse of laboratory resources.

Use of the Mean Abnormal Result Rate (MARR) to Gauge Changes in Family Physicians' Selectivity of Laboratory Test Ordering, 2010-2015.

The mean abnormal result rate (MARR) has recently been advanced as a metric of laboratory test appropriateness. We used the MARR metric to examine patterns of change in family physician test requisitions over time. We accessed the Laboratory Information System of Calgary Laboratory Services for family physician-ordered testing on outpatients to gather aggregate test and abnormal result counts from 2010 to 2015. Over the 6 years, there was an annual average of 3,401,553 tests for 411,295 distinct patients on their first test requisition for the year. The MARR increased from 8.1% to 9.0% through this period. The MARR for Calgary and surrounding area gives tentative evidence of a gradual increase in physician test selectivity in recent years. Further data from other catchment areas are needed before making assertions about broader trends in physician awareness of laboratory resource use.

Efficient use of laboratory resources: pre-screening for urine cultures by automated urinalysis and microscopy to allow exclusion of specimens from culture workflow

Abstract Background: Most of the urine cultures give negative results, leading to inefficient use of resources. The aim of this study was to evaluate and optimize screening by urinalysis and urine microscopy allowing elimination from the culture workflow, and find out if it might be cost effective in Turkey. Methods: A total of 1511 urine specimens were evaluated. Urinalysis and automated microscopy was performed by Iris iQ200 (Iris Diagnostics, USA). Results for nitrite, leukocyte esterase (LE), white blood cell (WBC), red blood cell (RBC) and all small particles (ASP) were compared to urine culture results. Savings were calculated, in case specimens predicted to be negative were not cultured. Results: Microbial growth was detected in 279 (18.5%) specimens. Using the most efficient algorithm, 400 (26.5%) specimens could be excluded from the workflow, leading to three (0.2%) false negatives. Second algorithm could predict negative result for 15.7% of the specimens with a negative predictive value (NPV) of 100%, saving $562. Conclusions: Screening urine specimens using multiple criteria might help predicting urine culture results. Although the cost of urine culture is low in Turkey, screening might still decrease cost and workload. All the variables should be considered to achieve efficient management of resources in the healthcare system without compromising patient safety.

Pathology use stewardship: pre-analytical review of tissue specimens previously processed by default for mycobacterial culture maintains the quality of laboratory diagnosis and optimises the use of laboratory resources

Pathology use stewardship: pre-analytical review of tissue specimens previously processed by default for mycobacterial culture maintains the quality of laboratory diagnosis and optimises the use of laboratory resources

Effectiveness of a computerized alert system based on re-testing intervals for limiting the inappropriateness of laboratory test requests

ObjectivesThere is consolidated evidence that the burden of inappropriate laboratory test requests is very high, up to 70%. We describe here the function of a computerized alert system linked to the order entry, designed to limit the number of potentially inappropriate laboratory test requests. Design and methodsA computerized alert system based on re-testing intervals and entailing the generation of pop-up alerts when preset criteria of appropriateness for 15 laboratory tests were violated was implemented in two clinical wards of the University Hospital of Parma. The effectiveness of the system for limiting potentially inappropriate tests was monitored for 6months. ResultsOverall, 765/3539 (22%) test requests violated the preset criteria of appropriateness and generated the appearance of electronic alert. After alert appearance, 591 requests were annulled (17% of total tests requested and 77% of tests alerted, respectively). The total number of test requests violating the preset criteria of inappropriateness constantly decreased over time (26% in the first three months of implementation versus 17% in the following period; p<0.001). The total financial saving of test withdrawn was 3387 Euros (12.8% of the total test cost) throughout the study period. ConclusionsThe results of this study suggest that a computerized alert system may be effective to limit the inappropriateness of laboratory test requests, generating significant economic saving and educating physicians to a more efficient use of laboratory resources.

Laboratory testing for platelet function disorders.

Platelet function testing is both complex and labor intensive. A stepwise approach to the evaluation of patients with suspected platelet disorders will optimize the use of laboratory resources, beginning with an appropriate clinical evaluation to determine whether the bleeding is consistent with a defect of primary hemostasis. Bleeding assessment tools, evaluation of platelet counts, and review of peripheral blood cell morphology can aid the initial assessment. For patients requiring further laboratory testing, platelet aggregometry, secretion assays, and von Willebrand factor assays are the most useful next steps and will direct further specialized testing including flow cytometry, electron microscopy, and molecular diagnostics. Guidelines and recommendations for standardizing platelet function testing, with a particular focus on light transmission aggregometry, are available and can provide a template for clinical laboratories in establishing procedures that will optimize diagnosis and assure quality results. This review outlines an approach to platelet function testing and reviews testing methods available to clinical laboratories.

Out-of-range international normalized ratio values and healthcare cost among new warfarin patients with non-valvular atrial fibrillation

Background:Patients with out-of-range international normalized ratio (INR) values <2.0 and >3.0 have been associated with increased risk of thromboembolic and bleeding events. INR monitoring is costly, because of associated physician and nurse time, laboratory resource use, and dose adjustments.Objectives:This study assessed the healthcare cost burden associated with out-of-range INR among warfarin initiator patients diagnosed with non-valvular atrial fibrillation (NVAF) in the US Veterans Health Administration (VHA) population.Methods:Adult NVAF patients (≥18 years) initiating warfarin were selected from the VHA dataset for the study period October 1, 2007–September 30, 2012. Only valid INR measurements (0.5 ≤ INR ≤ 20) were examined for the follow-up period, from the index date (warfarin initiation date) until the end of warfarin exposure or death. All-cause healthcare costs within 30 days were measured starting from the second month (31 days post-index date) to the end of the study period. Costs for inpatient stays, emergency room, outpatient facility, physician office visits, and other services were computed separately. Multiple regression was performed using the generalized linear model for overall cost analysis.Results:In total, 29,463 patients were included in the study sample. Mean costs for out-of-range INR ranged from $3419 to $5126. Inpatient, outpatient, outpatient pharmacy, and total costs were significantly higher after patients experienced out-of-range results (INR < 2, INR > 3), compared with in-range INR (2 ≤ INR ≤ 3). When exposed to out-of-range INR, patients also incurred higher mean total costs within 2–6 months ($3840–$5820) than after the first 6 months ($2789–$3503) of warfarin therapy.Conclusion:In the VHA population, INR measures outside of the 2–3 range were associated with significantly higher healthcare costs. Increased costs were especially apparent when INR values were below 2, although INR measures above 3 were also associated with higher costs relative to in-range values.

Dangers in the practice of defensive medicine in hemostasis testing for investigation of bleeding or thrombosis: part I--routine coagulation testing.

Defensive medicine is a term conventionally used for defining the medical (mal)practice of ordering medically questionable diagnostic testing, procedures, or visits, or to avoid high-risk patients or procedures. The practice of defensive medicine may primarily be aimed to reduce exposure to malpractice liability, to avoid patient criticism regarding "medical inaction," or to avoid "missing" some otherwise potential identifiable defect(s). Although the precise impact of defensive medicine in the field of laboratory testing is difficult to estimate from the current literature, the overuse or inappropriate use of laboratory resources ranges from 23 to 67%, and a large part of this can be attributed to medical liability concerns, with apparently little clinical awareness of the adverse consequences that may be associated with this practice. Essentially, performing inappropriate testing remarkably increases the risk of obtaining false-positive results due to statistical, preanalytical, and analytical reasons, thus triggering further and potentially even more invasive follow-up testing, inappropriate patient management, along with incremental increases of expenditure due to misuse of health care resources. As routine coagulation testing is commonly performed for the screening of patients with bleeding or thrombotic disorders, either a false-negative or a false-positive result may significantly impact on clinical outcomes and health care resources. The aim of this article is to describe the leading causes of physiological, pathological, therapeutic, and spurious variations of the prothrombin time, activated partial thromboplastin time, and D-dimer, as well as the potential clinical consequences emerging from the generation of false-negative and false-positive results with these tests.