Selection Of Patients For Testing Research Articles

Impact of a New Diagnostic Stewardship Team on Utilization and Interpretation of a Microbial Cell-Free DNA Detection Test

Abstract Background After commercial metagenomic next-generation sequencing of plasma microbial cell-free DNA (NGS-mcfDNA) became available at Children’s Healthcare of Atlanta (CHOA) in 2018 with an institutional requirement for Infectious Disease (ID) consultation and approval, we observed an initial period of test utilization without consistent ID involvement. Subsequently we assembled a Diagnostic Stewardship Team (DST) composed of a clinical microbiologist and 3 ID clinicians with expertise in diagnosis and management of infections in immunocompromised children and antimicrobial stewardship, to improve test utilization by clinicians and to optimally impact patient care. Methods We performed a retrospective medical record review as an IRB-deemed Quality Improvement project. NGS-mcfDNA results and their clinical impacts prior to the formation of the DST were assessed, using previously published standardized criteria as an initial framework (Hogan 2021)1. We shared our findings with Bone Marrow Transplant (BMT), Pediatric Intensive Care Unit (PICU), and ID clinicians, providing education on the potential benefits and limitations of NGS-mcfDNA testing. Stakeholder acceptability and engagement with the DST was prioritized, with emphasis on highlighting the benefits to clinicians of expertise in patient selection for testing and with interpretation of results which can be discordant with conventional microbiological tests. DST approval became required for all NGS-mcfDNA tests, with approval decision and discussion documented in the medical record, followed by documentation of test results, interpretation, and communications with treating and consulting clinicians. After one year of DST engagement, which began on June 1, 2021, we repeated our analysis of NGS-mcfDNA utilization and clinical impacts to evaluate the results of DST involvement. We classified time periods into pre-DST, February 28, 2018 - April 12, 2021, and post-DST, June 1, 2021 – May 31, 2022. Results The majority of NGS-mcfDNA tests sent in both the pre- and post-DST periods resulted in no or indeterminate clinical impact (65% pre-DST vs. 73% post-DST), while post-DST the percentage of positive clinical impacts increased (18% pre-DST vs. 25% post-DST), and the percentage of negative clinical impacts decreased (16% pre-DST vs. 2% post-DST), likely due to DST engagement. The number of tests per year increased by three-fold, while fewer patients had multiple NGS-mcfDNA tests sent. Awareness of the requirement for DST consultation and test approval lead to more selective NGS-mcfDNA test requests on the part of BMT clinicians, and the majority of positive clinical impacts from NGS-mcfDNA testing in BMT patients resulted from collaboration between BMT and ID in de-escalation of antimicrobials. An increased awareness of the potential benefits of NGS-mcfDNA testing for pre-treated and diagnostically challenging patients led to an increase in NGS-mcfDNA test requests from ID clinicians. Conclusion Implementation of a DST resulted in universal ID engagement with clinicians requesting NGS-mcfDNA tests and ID involvement in test interpretation. Discussion with experienced diagnostic stewards at the time of NGS-mcfDNA test consideration, with attention to the rationale for test request and consideration of potential test limitations prior to return of results, in addition to rigorous interpretation of results, can increase the positive clinical impacts and decrease the negative clinical impacts of NGS-mcfDNA tests. Reference 1. Hogan CA, Yang S, Garner OB, Green DA, Gomez CA, Dien Bard J, Pinsky BA, Banaei N. Clinical Impact of Metagenomic Next-Generation Sequencing of Plasma Cell-Free DNA for the Diagnosis of Infectious Diseases: A Multicenter Retrospective Cohort Study. Clin Infect Dis. 2021 Jan 27;72(2):239-245. doi: 10.1093/cid/ciaa035. PMID: 31942944. Characteristics of NGS-mcfDNA tests sent from CHOA NGS-mcfDNA tests in BMT patients post-DST (n=19 tests)

A Multidisciplinary Quality Improvement Project to Improve Appropriate Inherited Thrombophilia Testing at VA Connecticut

Background Many guidelines and expert opinions do not recommend inherited thrombophilia testing in unselected patients with venous thromboembolism (VTE), and per American Society of Hematology Choosing Wisely Recommendations, inherited thrombophilia testing is not recommended in patients with venous thromboembolism occurring in the setting of major transient risk factors. Furthermore, non-hematologists may lack knowledge on the effect of direct oral anticoagulants on these assays. From 2019 to 2021, 75% of inherited thrombophilia testing (protein C, S and antithrombin deficiencies and Factor V Leiden and prothrombin mutations) at VA Connecticut were ordered by non-hematologists. Of these orders, 55% of tests were ordered by primary care clinicians, 29% by inpatient teams, and the remainder by non-hematology specialists. Approximately 10% of testing by non-hematologists had abnormal results, generating further hematology consults and workup. Given that testing has limited clinical utility and can result in unnecessary downstream healthcare use, there is a need to improve guideline concordant and appropriate thrombophilia testing by non-hematologists. Methods The aim of this multidisciplinary quality improvement project was to decrease the number of inherited thrombophilia tests ordered by non-hematologists at VA Connecticut by 25% six months after our intervention implementation. Quality Improvement (QI) principles were used to identify root causes, which included complexity of and confusion over appropriate patient selection for testing, a lack of awareness of potential false positives with active anticoagulant use, limitations of our electronic medical record system (EMR) to provide clinical decision support tools to triage testing or provide education, and more. After multidisciplinary stakeholder engagement and feedback from hematology, internal medicine, laboratory medicine, and clinical informatics, we established a best practice alert (BPA) for inpatient and outpatient inherited thrombophilia testing at the time of order entry. Our BPA notified the ordering clinician that inherited thrombophilia testing rarely impacts the choice or duration of anticoagulation and is not recommended for most patients. The BPA recommended that as an alternative, clinicians can consider a hematology electronic consult (e-consult) for guidance and education regarding appropriate patient selection for testing. Data was collected from our EMR seven months after intervention initiation and analyzed via Excel 365. A control chart was used to assess the outcome measure, which was the number of orders for inherited thrombophilia testing by non-hematology clinicians per month. Our balancing measure was the number of hematology e-consults for inherited thrombophilia per month. Institutional pricing was used to determine costs associated with testing and potential cost savings. Results After our BPA implementation in January 2022, the mean number of monthly inherited thrombophilia tests from January to July 2022 decreased to 7.6 tests from 13.3 tests in 2021. All 7 monthly test order numbers post-implementation were below the mean, consistent with a potential trend towards a special cause variation shift. Inpatient testing decreased from 40 total tests in 2021 to 7 tests since implementation. The average cost of testing per month decreased from $653 to $366 with an estimated $2004 saved after intervention implementation. The mean number of hematology e-consults for inherited thrombophilia related questions increased to 3.4 consults per month during the first five months of the intervention period from 2.5 consults per month in 2021. Conclusion A best practice alert in the EMR reminding clinicians about the limited role of inherited thrombophilia testing in unselected patients and the option for hematology e-consult for further specialist guidance was associated with a trend towards reduced inherited thrombophilia testing. Furthermore, there were decreased costs associated with testing without any substantial increase in workload for the hematology service. The BPA remains in place, and data collection and analysis are ongoing. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Abstract 14211: Positive Predictive Value of Troponin for NSTEMI Based on Chief Complaint

Introduction: Serum troponin is a ubiquitous biomarker used to diagnose acute myocardial infarction (AMI). The positive predictive value (PPV) of high-sensitivity troponin for Type 1 Myocardial Infarction is approximately 15% in the United States, compared with 55% in Europe, a difference that may be explained by differences in patient selection for testing. Our objective was to examine test characteristics for contemporary troponin assays based on chief complaint in the Emergency Department (ED). Methods: In a retrospective cohort analysis, we examined all 30,833 encounters in which a troponin test was performed in any of the 14 emergency departments within a large integrated health system between 10/1/18 and 10/1/19. All hospitals used a contemporary cardiac troponin-I (cTnI) assay. We excluded patients with ST-segment elevation myocardial infarction (STEMI) since this diagnosis is made by electrocardiogram. We grouped patients by chief complaint (CC) and further stratified by pre-specified cTnI thresholds. Within each cTnI/CC category, we calculated the proportion of patients subsequently classified with a principal ICD-10 diagnosis of non-STEMI (NSTEMI). Results: For all patients selected for cTnI testing, 1.7% were diagnosed with NSTEMI. Overall, the PPV of cTnI for NSTEMI was 11%. This PPV for NSTEMI was highest among patients with chest pain (33%). Excluding patients with chest pain, the PPV for NSTEMI was 3.9%. For nearly all chief complaints, the PPV for NSTEMI increased with higher cTnI thresholds. Conclusion: In a large integrated health system, fewer than one in fifty patients undergoing cTnI testing in the ED were ultimately diagnosed with NSTEMI. The PPV of cTnI for NSTEMI was significantly higher among patients presenting with chest pain compared to other chief complaints. These data highlight the importance of selecting patients for testing and interpreting abnormalities in the context of presenting symptoms.

Assessment of tumor sequencing rates in ovarian cancer patients

Objective: Tumor gene sequencing can identify targetable mutations with potential prognostic and predictive therapeutic implications. There are no specific recommendations regarding patient selection for testing. Herein, we investigated tumor sequencing referral patterns and completion rates in ovarian cancer patients as well as the impact of testing on treatment plan.

2362. Back to the Future: The Impact of Multi-Step Algorithm C. difficile Testing at a Large Tertiary Medical Center

BackgroundAntibiotic stewardship and infection control programs rely on C. difficile infection (CDI) test results to measure CDI incidence in the hospital setting. C. difficile carriage is common and distinguishing infection from colonization is difficult with the highly sensitive nucleic acid amplification testing (NAAT) commonly used. Current guidelines recommend a multi-step algorithm for testing. The impact on patient outcomes and CDI metrics are largely unknown.MethodsThis was a pre-post study at the University of Maryland Medical Center, evaluating the impact of a CDI testing strategy (introduced October 2018) that simultaneously reported NAAT and confirmatory enzyme immunoassay (EIA) when used with existing best practice alerts for appropriate testing. Pre-intervention (November 2017–September 2018) and post intervention (October 2018–March 2019) periods were compared for mean CDI incidence (CDI per 10,000 admissions) defined by: (1) positive NAAT, (2) reported CDI (last positive test), and (3) treated CDI (receiving oral vancomycin). Both community and hospital-onset cases were included. The NAAT CDI incidence was used as the pre-intervention comparison for all 3 measures. In addition, oral vancomycin days of therapy (DOT) per 1,000 patient-days (PD) was compared. Pre–post comparisons of mean CDI incidence and mean DOT rates were done using Student t-test.ResultsThere were 3,237 samples tested (2,269 pre and 968 post-intervention) with 376 NAAT positive (262 pre and 114 post-intervention). Of the 99 tests with reflex EIA, there were 74 discordant tests (NAAT +/EIA -) with 35 (47%) treated for CDI. Mean NAAT CDI incidence pre-intervention was 54 per 10,000 admissions. Post-intervention mean CDI incidence decreased as follows: 45 NAAT CDI per 10,000 admissions (P = 0.13), 15 reported CDI per 1000 admissions (P < 0.0001), and 28 treated CDI per 10,000 admissions (P = 0.0007). Oral vancomycin DOT per 1,000 PD decreased from 16 to 9 (P = 0.0002).Conclusion C. difficile NAAT testing with confirmatory EIA, in combination with best practice alert, decreased reported and treated cases of CDI, which may distinguish infection vs. colonization and avoid unnecessary treatment, beyond that achieved with alerts that improve appropriate patient selection for testing. Disclosures All authors: No reported disclosures.

Appropriate Patient Selection Leads to Improvement in Healthcare Facility-Onset C. diff Rates

BACKGROUND Healthcare facility-onset Clostridium difficile infections (HO CDI) are potentially preventable events associated with increased cost, morbidity, and mortality in adult patients. Struggling with a high HO CDI rate, our facility identified appropriate patient selection for testing as an improvement opportunity. Careful patient selection for C. diff testing is vital to improve the sensitivity and specificity of HO CDI diagnosis. METHODS A dyad approach was developed to improve CDI testing practices. A rule was built into the electronic medical record that automatically cancelled C. diff orders if the sample was not ?collected within 24?hours of order. A C. diff Ticket-to-Lab (TTL) form with an accompanying testing algorithm was developed to guide clinicians through determining whether or not a patient should be tested for C. diff based on clinical criteria. All C. diff tests were required to have a TTL form filled out before submission to the laboratory. RESULTS Cancellation of outdated results reduced the average amount of C. diff tests performed monthly by 40%. After implementation of TTL, our HO CDI standardized infection ratio (SIR) dropped by 42% from 1.29 during the baseline period to 0.552 post intervention (p-value 0.0094, 95% confidence interval 0.209, 0.821). CONCLUSIONS A combination of electronic and manual tools can be used to assist providers in identifying patients with clinical criteria that warrants C. diff testing. Improving patient selection for C. diff testing is an effective strategy to reduce HO CDI. Detection of C. diff colonization is prevented along with unnecessary antibiotic use, prolonged length of stay and hospital penalties associated with falsely inflated HO CDI rates.

Hematological Malignancies in Adults With a Family Predisposition.

Some hematological malignancies arise in persons with a hereditary predisposition. The hereditary nature of these diseases often goes unrecognized, particularly when symptoms begin in adulthood. This review is based on pertinent publications retrieved by a selective search in PubMed. Many rare germline mutations have been identified that lead to acute leukemia and myelodysplastic syndromes. They differ from one another with respect to their penetrance, the age of onset of disease, and the clinical manifestations. In view of this heterogeneity, no uniform recommendations have yet been formulated for their diagnosis and treatment. The most common types of hematological malig- nancy with a hereditary predisposition are traceable to an underlying disturbance of DNA damage response and repair mechanisms and to mutations of hematological transcription factors. With regard to the selection of patients for testing, the con- sensus is that cytogenetic and molecular-genetic findings that are suspect for a hereditary predisposition, such as CEBPA and RUNX1 mutations, call for further investigation, as do any clinical features that are typical of tumor syndromes, or a positive family history. The knowledge that a hereditary predisposition may be present is highly stressful for patients; testing should only be carried out after the patient has received genetic counseling. The confirmation of a germline mutation always requires a comparison with healthy tissue. A fibroblast culture is recom- mended as the gold standard for this purpose. The detection of a hereditary predisposition to hematological neoplasia is often relevant to treatment and follow-up care: for example, it may motivate early allogeneic stem-cell transplantation. Counseling, predictive testing, and follow-up care are available to the patients' relatives as well.

Availability of Zika Virus Testing Information on Local Health Department Websites in the State of Texas [14O

INTRODUCTION: Zika virus infection is an emerging health threat. It is important that obstetric providers can easily access Zika virus testing information. Our objective was to evaluate the availability of information about Zika virus testing on county and regional health department websites in Texas. METHODS: We reviewed all Texas county, regional, and metropolitan health department websites for information on testing patients with suspected Zika virus infection. Information abstracted included education on appropriate patient selection for testing, where to have blood drawn, where to submit specimens, availability of testing forms, and contacts for additional testing information. In cases where information about Zika virus testing did not appear immediately on the main webpage, an internal search of the site using the terms “Zika” was performed. RESULTS: Information for providers about Zika virus testing was identified on 3.1% of 254 county health department websites, 9.1% of the 11 public health region websites, and 5.0% of the 39 metropolitan health department websites. Very few websites had access to testing guidelines and testing forms available for providers. CONCLUSION: Growing concerns about Zika virus warrant guidance for healthcare providers on testing. The Centers for Disease Control recommends patients contact healthcare providers for guidance on testing, and that providers seek guidance from local public health departments. Providers in Texas have poor access to local and regional information for testing through these online resources. Improved local efforts are needed to assist providers with guidance on Zika testing.

Cell cycle progression score and treatment decisions in prostate cancer: results from an ongoing registry

Objective:The cell cycle progression (CCP) test (Prolaris) is a novel prognostic assay that provides accurate risk of prostate cancer-specific disease progression and disease specific mortality when combined with standard clinicopathologic parameters. This prospective study evaluated the impact of the CCP report on physician treatment recommendations for prostate cancer.Methods:Physicians ordering the CCP test in clinical practice completed surveys regarding treatment recommendations before and after they received and discussed the test results with patients. Clinicians also rated the influence of the test result on treatment decisions. Treatment selections were confirmed via third-party audit of patient charts following final survey responses.Results:Overall, 65% of cases showed a change between intended treatment pre- and post-CCP test reporting. Pre-CCP testing, 164 of 305 cases received a recommendation for interventional treatment. Post-CCP test, interventional therapy was recommended for 103 of these cases, a reduction of 37.2%. Conversely, 141 of 305 cases were recommended pre-CCP testing for non-interventional treatment; 108 of these remained with non-interventional treatment while 33 shifted to interventional options, a 23.4% increase. There was a 49.5% reduction in surgical interventions and a 29.6% reduction in radiation treatment. A third-party audit identified 80.2% concordance between the post-CCP testing treatment recommendation and actual treatment. Re-assignment to intervention or non-intervention generally correlated with the result of the CCP report. Study limitations included physician selection of patients for testing, no evaluation of patient input in therapeutic choice, and other potential treatment decision factors not queried by the survey.Conclusion:Based on responses of ordering physicians, the CCP report adds meaningful new information to risk assessment for localized prostate cancer patients. Test results led to changes in treatment with reductions and increases in interventional treatment that were directionally aligned with prostate cancer risk specified by the test.

Desire for and use of genetic testing in a population-based sample of breast cancer patients.

6615 Background: Prior research suggests that receipt of genetic testing to assess risk of disease in patients or their families is not limited to those who meet high-risk criteria (i.e., diagnosed at young age &amp;/or with strong family history). There is little research from large population-based samples describing patterns and correlates of genetic testing receipt or reasons why patients undergo testing. Methods: We surveyed 2290 women newly diagnosed with breast cancer reported to the Detroit &amp; Los Angeles SEER registries from 6/05-2/07. We merged these data to SEER and re-surveyed them again approximately 4 years later (n=1536). The primary outcomes were patient reports of a strong desire for genetic testing, participation in a discussion about genetic testing, and receipt of genetic testing. We also evaluated patient reports of reasons for getting tested. We compared dependent and independent factors using chi-square tests and used logistic regression to evaluate correlates of each outcome. Results: One third (33.9%) reported a strong desire to be tested, of whom 54% discussed testing with a health professional, &amp; 46% were tested. A strong desire to be tested was associated with younger age (F=32.03, P&lt;0.001), minority race (F=62.5, P&lt;0.001), family history of breast &amp;/or ovarian cancer (F=18.5, P&lt;0.001) and worry about recurrence (OR: 1.8; 95% CI: 1.3-2.6). Overall, 19.3% were tested. Test receipt was significantly associated with younger age (F=26.8, P&lt;0.001), higher education (OR: 1.8; 95% CI:1.13-2.71), and family history (F=25.1, P&lt;0.001). Of those tested, reasons included: physician recommendation (61.8%), wanting more information about one’s own health (51.8%), wanting more information for family (54.2%), and family desire (13.6%). 7.8% of those not tested indicated it was because of the expense. Conclusions: Many women have a strong desire for genetic testing after diagnosis of breast cancer but often do not discuss testing with professionals. Desire for testing was correlated with pertinent clinical factors but also non-clinical factors such as minority race and worry about recurrence. Results suggest the continued need to address patient desire for testing and selection of appropriate patients for testing.

Patterns and Predictors of Stress Testing Modality After Percutaneous Coronary Stenting: Data From the NCDR®

We evaluated temporal trends and geographic variation in choice of stress testing modality after percutaneous coronary intervention (PCI), as well as associations between modality and procedure use after testing. Stress testing is frequently performed post-PCI, but the choices among available modalities (electrocardiography only, nuclear, or echocardiography; pharmacological or exercise stress) and consequences of such choices are not well characterized. CathPCI Registry(®) data were linked with identifiable Medicare claims to capture stress testing use between 60 and 365 days post-PCI and procedures within 90 days after testing. Testing rates and modality used were modeled on the basis of patient, procedure, and PCI facility factors, calendar quarter, and Census Divisions using Poisson and logistic regression. Post-test procedure use was assessed using Gray's test. Among 284,971 patients, the overall stress testing rate after PCI was 53.1 per 100 person-years. Testing rates declined from 59.3 in quarter 1 (2006) to 47.1 in quarter 4 (2008), but the relative use of modalities changed little. Among exercise testing recipients, adjusted proportions receiving electrocardiography-only testing varied from 6.8% to 22.8% across Census Divisions; and among exercise testing recipients having an imaging test, the proportion receiving echocardiography (versus nuclear) varied from 9.4% to 34.1%. Post-test procedure use varied among modalities; exercise electrocardiography-only testing was associated with more subsequent stress testing (13.7% vs. 2.9%; p < 0.001), but less catheterization (7.4% vs. 14.1%; p < 0.001) than imaging-based tests. Modest reductions in stress testing after PCI occurring between 2006 and 2008 cannot be ascribed to trends in use of any single modality. Additional research should assess whether this trend represents better patient selection for testing or administrative policies (e.g., restricted access for patients with legitimate testing needs). Geographic variation in utilization of stress modalities and differences in downstream procedure use among modalities suggest a need to identify optimal use of the different test modalities in individual patients.

Abstract 70: Exercise Stress Testing Modality after Percutaneous Coronary Intervention - Choice of Modality and Implications for Resource Use: Retrospective Analysis using the NCDR®

OBJECTIVES: Exercise stress testing is frequently performed post PCI, but the choices amongst the modalities available (ECG-only, nuclear, or echocardiography) and consequences of such choices are not well characterized. We evaluated temporal trends and geographic variation in the choice of exercise testing modality post PCI, as well as associations between modality choice and procedure use after testing. METHODS: CathPCI Registry® data were linked with identifiable Medicare claims to capture stress testing use between 60 and 365 days after PCI and procedures within 90 days after testing. Testing rates and modality used were modeled based on patient, procedure, and PCI facility factors, calendar quarter, and Census Divisions using Poisson and logistic regression. Post stress test/procedure use was assessed using Gray's test. RESULTS: In 286,099 patients, the overall stress testing rate after PCI was 53.1 per 100 person-years. The rate declined from 59.5 in Q1 2006 to 47.2 in Q4 2008 (p&lt;0.001), but the proportion of all stress tests performed with exercise and the proportion of all exercise tests performed with each modality changed little. After statistical adjustment, the proportion of exercise test recipients receiving ECG-only testing (vs. any stress imaging) varied from 8.7%-21.1% across divisions (p&lt;0.001). Among exercise stress imaging recipients, the proportion receiving echocardiography (vs. nuclear) varied from 9.1%-31.2% across divisions (p&lt;0.001). Rates of post-test procedure use varied among modalities; exercise ECG-only testing was associated with more subsequent stress testing (14.6% vs. 1.9%; p&lt;0.001), but less catheterization (8.4% vs. 15.3%; p&lt;0.001) than imaging-based tests. CONCLUSIONS: Modest reductions in stress testing after PCI occurring between 2006 and 2008 cannot be ascribed to trends in use of any single modality. Additional research should assess whether this trend represents better patient selection for testing or administrative policies (e.g., restricted access for patients with legitimate testing needs). Geographic variation in utilization of exercise stress modalities and differences in downstream procedure use among modalities suggest a need to identify optimal use of the different test modalities.

S1027 Which Drugs Are Safe in Male and Female Patients Considering Conception, and in Pregnant Women and Nursing Mothers, with Crohn's Disease? Results of a Multidisciplinary International Expert Panel (EPACT II)

BODY: Introduction: Biological therapy has dramatically changed the management of Crohn's disease (CD). Appropriateness criteria for maintenance treatment after medically-induced remission (MIR) or surgically-induced remission (SIR) of CD have thus been updated. Formal evidence is weak formany therapeutic decisions regardingmaintenance treatment for CD and thus clinically-explicit and situation-tailored criteria made freely available on the internet will be helpful to physicians in daily decision-making in clinical practice. Methods: Multidisciplinary international experts (EPACT II, Geneva, Switzerland) discussed and anonymously rated virtual clinical indications on the basis of evidence in the literature. Median ratings (on a 9-point scale) were stratified according to three assessment categories: appropriate (7-9), uncertain (4-6 and/or disagreement) and inappropriate (1-3). Experts were also asked to rank appropriate medication according to their own clinical practice, without any consideration of cost. Results: 392 specific indications for maintenance treatment of CD were rated (200 for MIR and 192 for SIR). Azathioprine, methotrexate and/ or anti-TNF antibodies were considered appropriate in 42 indications, corresponding to 68% of all appropriate interventions (97% ofMIR and 39%of SIR). The remaining appropriate interventions consisted of mesalazine and a “wait-and-see” strategy. Factors that influenced the panel's voting were patient characteristics and outcome of previous treatments. Results favor the use of anti-TNF agents after one failure of any immunosuppressive therapy, while an earlier use is still controversial. Conclusion: Detailed explicit appropriateness criteria have been updated for maintenance treatment of CD. New expert recommendations for the use of the classic immunomodulators as well as anti-TNF agents are now available (www.epact.ch). The validity of these criteria should now be tested by prospective evaluation. A-173 AGA Abstracts S1029 Clinical Use and Outcomes from IBD Serology Testing in a Tertiary Referral Center Alan C. Moss, Adam Cheifetz, Nabeel Chaudhary, Jahvari Junior Background Testing for a combination of antibodies against ASCA, ANCA, and OmpC has become common-place in IBD practice. Patient selection for testing, and the impact of test results on patient management, remain variable. Aims To describe patient selection for IBD antibody testing in a tertiary referral center. To measure changes in management after test results became available. To compare test results between patient sub-groups. Methods Review of electronic medical records of all patients who completed IBD serology testing (Prometheus) at a single institution. Results Data were available on 213 patients who completed testing. The distribution of pre-testing diagnoses were as follows; no diagnosis 41 (19%), Crohn's disease 49 (23%), ulcerative colitis 60 (28%), IBD unclassified 60 (28%). In those with established IBD, 122 (57%) had colonic disease only, 36 (17%) had small bowel disease only, 13 (6%) had ileo-colonic disease, and 10 (5%) had pouchitis. The prevalence of elevated antibodies to ASCA, ANCA and OmpC in different patient populations can be seen in Table 1. The proportion of patients with a change in diagnosis after antibody testing in each patient sub-group was as follows; no diagnosis 27%, Crohn's disease 48%, ulcerative colitis 20%, IBD unclassified (IBDU) 63%. The odds ratio of a change in diagnosis after testing positive for ASCA, ANCA or OmpC was not statistically significant in any patient sub-group. A cohort of patients also underwent antibody testing for celiac disease antibodies (n=21), but all were negative. Conclusions IBD serology testing was applied to a wide range of patient populations in this center. ASCA antibodies were present in similar proportions across all patient populations. Patients with IBDU were most likely to have a change in diagnosis after antibody testing.

Hypercoagulable states

The incidence of venous thromboembolism (VTE) in the USA is approximately 1 per 1000 with over 200,000 new cases per year. Despite improved methods for antithrombotic prophylaxis, the incidence of VTE has remained constant for the last 20 years and about 30% of patients developing VTE die within 30 days. Risk factors for VTE include advancing age, obesity, recent surgery or trauma, hospital or nursing home confinement, malignancy, and stroke; among women, pregnancy, oral contraceptives, and hormone replacement therapy play a significant role. Prior to 1993, a cause of thrombophilia was detectable in a relatively small percentage of patients presenting with VTE. Hereditary abnormalities were found in only 5 to 15% of patients and were confined to deficiencies of antithrombin, protein C, and protein S. Discovery of the factor V Leiden and prothrombin G20210A mutations has greatly increased the percentage of Caucasian patients in whom venous thrombosis can, in part, be attributed to hereditary thrombophilia. It has also been demonstrated that elevated plasma homocysteine levels constitute a risk factor for venous as well as arterial thrombosis. These abnormalities, along with the presence of markers of the antiphospholipid antibody syndrome can be identified in a substantial percentage of patients presenting with a first episode of idiopathic venous thromboembolism (i.e. in the absence of a triggering risk factor such as surgery, immobilization, or active malignancy). Testing for the hereditary thrombophilias is warranted in selected subsets of such patients, particularly those with a history of venous thromboembolism in first degree relatives. The selection of patients for testing, the choice of tests to perform, and the timing of the testing are important issues to consider. Routine testing of unselected patients with venous thromboembolism would be warranted if the identification of abnormalities led to an alteration in the type or duration of initial anticoagulant therapy. However with the exception of the antiphospholipid antibody syndrome, the available data do not indicate that the anticoagulation management of the majority of patients with hereditary thrombophilia should be any different from those without identifiable abnormalities. The risk of recurrent venous thromboembolism in patients with an initial episode of venous thromboembolism will be discussed along with the impact of a thrombophilic defect and the likely benefit of prolonged anticoagulation versus the associated bleeding risk associated with prolonged anticoagulation.

The thrombophilias: well-defined risk factors with uncertain therapeutic implications.

Discovery of the factor V Leiden and prothrombin G20210A mutations has greatly increased the percentage of patients in whom venous thrombosis can be attributed to hereditary thrombophilia. The first step in the diagnostic approach to all patients with venous thrombosis consists of a careful history and physical examination combined with routine laboratory testing to characterize the severity of the thrombotic condition and determine the presence of any of the acquired causes of hypercoagulability. The second step is to consider screening for the causes of hereditary and acquired thrombophilia in selected subsets of patients. The selection of patients for testing, the choice of tests to perform, and the timing of the testing are important and challenging issues to consider. Routine testing would be warranted if the identification of abnormalities led to an alteration in the type or duration of initial anticoagulant therapy or the use of long-term prophylactic anticoagulation. The available data, however, do not yet indicate that most patients with defined thrombophilic states should be managed any differently than patients without identifiable abnormalities. On the basis of relative prevalences of the various thrombophilias, patients can be classified as "strongly" or "weakly" thrombophilic depending on their thrombotic histories. Management considerations and guidelines are offered for patients who are found to have one or more defined abnormalities, hereditary or otherwise. The future identification of additional laboratory abnormalities predisposing patients to thrombosis, coupled with prospective clinical trials, should enable us to better identify patients at high risk for recurrence who will benefit from prolonged anticoagulant prophylaxis.

Cost-effectiveness of stress echocardiography for assessment of coronary artery disease: what we know and what we need to know.

This review explores the balance between the incremental data supplied by stress echocardiography and its cost. This technique is now established as an accurate tool for the diagnosis of coronary artery disease and myocardial viability, but the current medical-economic environment mandates careful consideration of the impact of the results on patient outcomes. The tools for assessment of cost and efficiency are reviewed. Two considerations are explored for controlling costs; avoidance of testing in those who will derive limited incremental data, and appropriate selection of stress echocardiography rather than other stress techniques. The balance between diagnostic accuracy and cost is explored in observational studies and computer models. Finally, the prognostic implications of testing are evaluated and data from the stress testing literature are explored to show that more effective patient selection for interventions may justify greater expenditure on testing. The appropriate selection of patients for testing has a significant evidence base. The cost of identifying coronary disease has been examined in a number of studies and facilitates the selection between testing modalities. Prognostic data are increasingly available, and further work is needed to combine this with cost analysis in order to show that stress echocardiography, like other stress modalities, may be used to guide therapy and thereby improve cost-effective outcomes.

The diagnosis of chlamydial infection in a cytology laboratory: ten months' experience using immunofluorescence with and without previous cytologic prediction.

A Chlamydia diagnostic service has been established as part of a cytology laboratory, combining prediction of possible infection by routine cytology with definitive testing by immunofluorescence. The first 10 mo of operation have had good clinician acceptance with 527 specimens submitted and 128 reported as positive (24.3%). Routine cytology was more accurate in predicting chlamydial infection than was clinical evaluation (32.8% of cytologically suspected cases were positive versus 20.2% of clinically suspected cases); however, both failed to identify many infected women. The patient selection for testing must be improved since only about 22% of infected women in our population were tested. Nevertheless, the service identified a large number of patients infected with an important sexually transmitted pathogen. Chlamydial diagnosis has become a major component of the laboratory's workload and has been cost-effective.

Tuberculin reactors among children in highly infected Chicago areas.

Interest in tuberculosis in childhood, acquired during several years of observation of children in the Mantoux Clinic at Children's Memorial Hospital and the Pediatric Chest Clinic at Michael Reese Hospital led to a study of the incidence of tuberculin reactors among the clinic populations of these institutions. The pupils at one elementary school in close proximity to Michael Reese Hospital were also tested. Organization of Study A. Michael Reese Hospital.—The study ran over an 11-month period—June, 1952, to May, 1953. Selection of patients for testing was made at random in the General Pediatric Clinic, 15 to 20 children being tested at four clinic sessions weekly on Monday, Wednesday, Thursday, and Friday. Readings were made 96 hours later, except for the tests applied on Wednesday, which were read after 120 hours. The Vollmer patch test was used, with the patch applied to the intrascapular area to the left of the