The "most bothersome symptom" construct: A qualitative study of Australians living with endometriosis.

INTRODUCTION: "Improvement in the most bothersome symptom" was recently selected as a core outcome for endometriosis intervention trials. This study aimed to explore the applicability of the construct of "symptom bother" in representing the lived experiences of people with endometriosis. MATERIAL AND METHODS: Semi-structured interviews were conducted to understand the meaning of "symptom bother" and related constructs. Eighteen interviews were conducted: 14 among people with a surgical diagnosis of endometriosis who were recruited from the community, and four with people who were recruited from a private gynecology clinic who had either a confirmed diagnosis or a high suspicion of the disease. All interviews were audio recorded, transcribed verbatim, and analyzed thematically. RESULTS: Three primary themes were identified: (1) endometriosis symptoms and priorities vary with time and context, (2) endometriosis symptoms impair normal daily functioning, (3) endometriosis symptoms are more than just a "bother." The concept of "bother" to describe endometriosis symptoms did not resonate with most participants. Whilst "bother" was familiar language, it did not encompass the broader implications of living with endometriosis. Participants felt "bother" implied emotional distress, lacking a full understanding of the consequences of the disease. Instead, "symptom impact" was endorsed, allowing participants to quantify and objectively assess their symptoms, free from negative connotations. CONCLUSIONS: This was the first qualitative study to explore "symptom bother" among people living with endometriosis. Instead of "bother," "impact" was widely endorsed as a suitable construct. This term more appropriately captured the broad ways in which endometriosis symptoms impair daily functioning.

Implementation of a compulsory clinical pharmacist-led medication deprescribing intervention in high-risk seniors in the emergency department.

OBJECTIVES: The objective of this study was to assess the impact of an emergency department (ED) deprescribing intervention for geriatric adults. We hypothesized that pharmacist-led medication reconciliation for at-risk aging patients would increase the 60-day case rate of primary care provider (PCP) deprescribing of potentially inappropriate medications (PIMs). METHODS: This was a retrospective, before-and-after intervention pilot study conducted at an urban Veterans Affairs ED. In November 2020, a protocol utilizing pharmacists to perform medication reconciliations for patients 75 years or older who screened positive using an Identification of Seniors at Risk tool at triage was implemented. Reconciliations focused on identifying PIMs and providing deprescribing recommendations to patients' PCPs. A preintervention group was collected between October 2019 and October 2020, and a postintervention group was collected between February 2021 to February 2022. The primary outcome compared case rates of PIM deprescribing in the preintervention group to the postintervention group. Secondary outcomes include per-medication PIM deprescribing rate, 30-day PCP follow-up visits, 7- and 30-day ED visits, 7- and 30-day hospitalizations, and 60-day mortality. RESULTS: A total of 149 patients were analyzed in each group. Both groups were similar in age and sex, with an average age of 82 years and 98% male. The case rate of PIM deprescribing at 60 days was 11.1% preintervention compared to 57.1% postintervention (p < 0.001). Preintervention, 91% of PIMs remained unchanged at 60 days compared to 49% (p < 0.05) postintervention. Regardless of PIM identification, the 30-day primary care follow-up rate increased postintervention: 31.5% and 55.7% (p < 0.0001), respectively. There was no improvement in 7- or 30-day subsequent ED visits, hospitalization, or mortality. CONCLUSIONS: Pharmacist-led medication reconciliation in high-risk geriatric patients was associated with an increase both in the rate of PIM deprescribing and in post-ED primary care engagement.

Health seeking behaviours and treatments received by Australian women with vulvodynia: A cross-sectional survey.

BACKGROUND: Vulvodynia is a condition characterised by pain in the vulva lasting more than three months and for which no obvious aetiology can be found. It affects around 8% of women and has significant negative impacts on quality of life. There is a paucity of research on healthcare management pathways and the use of evidence-based treatments in an Australian community setting. AIMS: To explore which healthcare professionals Australian women with vulvodynia seek treatment from, and which treatments are recommended, provided, or prescribed by these healthcare professionals. MATERIALS AND METHODS: A cross-sectional online survey was conducted from May 2019 to August 2019. Women were eligible to participate if they had been diagnosed with vulvodynia by a healthcare professional, were currently living in Australia, and were over 18 years old. RESULTS: Fifty respondents meet the inclusion criteria, with a mean age of 30.5 years. On average, respondents reported seeing four different types of healthcare professionals in the management of their vulvodynia, with general practitioners (GPs) (98%), medical specialists (96%), and physiotherapists (80%) being the three most commonly consulted. Most respondents reported seeing multiple GPs (>87%), multiple medical specialists (>77%), and multiple physiotherapists (50%). The most commonly prescribed interventions were pelvic floor down-training exercises (76%), topical (70%) and oral (70%) medication, and vulvodynia information (56%). CONCLUSIONS: Australian women with vulvodynia seek help from several professionals and receive a variety of treatments for their pain. Of concern is many treatments that are being offered clinically have very little peer-reviewed evidence of effectiveness in vulvodynia.

Emergency Department Utilization in Children <36 Months Is Not an Independent Risk Factor for Maltreatment.

BACKGROUND AND OBJECTIVES: Early childhood high-frequency use (HFU) of the emergency department (ED) has been endorsed as a marker for increased risk of child maltreatment. In a prior analysis of pediatric ED (PED) visits by 16,664 children, 0-36 months old, we defined early childhood HFU (the 90th percentile) as five or more visits. The purpose of this study was to follow HFU patients to determine if they had a higher likelihood of reported maltreatment. METHODS: This is a single-center, cross-sectional, observational study of the association between PED use in early life and subsequent intervention by child protective services (CPS). CPS data were obtained from a Department of Social Services database for subjects meeting criteria for PED HFU as well as sex, race, and ethnicity-matched controls. Multivariable analyses were performed to assess if HFU was independently associated with child maltreatment. RESULTS: While CPS involvement was more highly represented in the group with PED HFU, so were many confounding variables such as African American race, history of hospital admissions, and social work consultations in the PED for any reason. HFU, by itself, is not a risk factor for a major intervention by CPS. CONCLUSIONS: In efforts to identify children at risk for maltreatment, objective assessments such as PED utilization are potential markers to utilize to aid in recognition. Unfortunately, there are many risk factors for increased PED utilization that act as confounders for this marker. Future work is necessary to identify children at risk for maltreatment in the ED.

Major Adverse Events One Year After Acute Kidney Injury After Contrast-Enhanced Computed Tomography.

STUDY OBJECTIVE: Recent studies have demonstrated that a single episode of acute kidney injury from a number of causes can increase the risk of severe long-term outcomes, including major cardiovascular events and death. We tested the hypothesis that patients who develop acute kidney injury consistent with contrast-induced nephropathy after contrast-enhanced computed tomography (CT) imaging are at increased risk of major adverse events at 1 year. METHODS: We followed a prospective, heterogeneous cohort of consecutive emergency department patients undergoing contrast-enhanced CT for the outcomes of acute kidney injury consistent with contrast-induced nephropathy and major adverse events, defined as the combined outcome of death (all cause), renal failure, myocardial infarction, and stroke or other arterial vascular events, in any anatomic territory, requiring invention within 1 year. The primary outcome, major adverse events, was determined by the consensus of 2 of 3 blinded adjudicators. RESULTS: We followed 633 patients undergoing contrast-enhanced CT, of whom 11% developed acute kidney injury consistent with contrast-induced nephropathy and 15% (95/633; 95% confidence interval [CI] 12% to 18%) experienced at least 1 major adverse event within 1 year, including 7% (46/633; 95% CI 5% to 9%) who died. The development of acute kidney injury after contrast-enhanced CT was associated with an increased risk of 1-year major adverse event: the incident risk ratio was 4.01 (95% CI 2.61 to 6.05) and was 2.36 (95% CI 1.49 to 3.75) after adjusting for age, existing coronary artery disease, active malignancy, and 1 or more additional exposures to intravascular iodinated contrast media. CONCLUSION: The development of acute kidney injury after contrast-enhanced CT was associated with a 2-fold increase in 1-year major adverse events. Further research is needed to validate this observation.

Cost-effectiveness of quantitative pretest probability intended to reduce unnecessary medical radiation exposure in emergency department patients with chest pain and dyspnea.

OBJECTIVES: Quantitative pretest probability (qPTP) incorporated into a decision support tool with advice can reduce unnecessary diagnostic testing among patients with symptoms suggestive of acute coronary syndrome (ACS) and pulmonary embolism (PE), reducing 30-day costs without an increase in 90-day adverse outcomes. This study estimates long-term (beyond 90-day) costs and outcomes associated with qPTP. The authors hypothesized that qPTP reduces lifetime costs and improves outcomes in low-risk patients with symptoms suggestive of ACS and PE. METHODS: This was a cost-effectiveness analysis of a multicenter, randomized controlled trial of adult emergency patients with dyspnea and chest pain, in which a clinician encountering a low-risk patient with symptoms suggestive of ACS or PE conducted either the intervention (qPTP for ACS and PE with advice) or the sham (no qPTP and no advice). Effect of the intervention over a patient's lifetime was assessed using a Markov microsimulation model. Short-term costs and outcomes were from the trial; long-term outcomes and costs were from the literature. Outcomes included lifetime transition to PE, ACS, and intracranial hemorrhage (ICH); mortality from cancer, ICH, PE, ACS, renal failure, and ischemic stroke; quality-adjusted life-years (QALYs); and total medical costs compared between simulated intervention and sham groups. RESULTS: Markov microsimulation for a 40-year-old patient receiving qPTP found lifetime cost savings of $497 for women and $528 for men, associated with small gains in QALYs (2 and 6 days, respectively) and lower rates of cancer mortality in both sexes, but a reduction in ICH only in males. Sensitivity analysis for patients aged 60 years predicted that qPTP would continue to save costs and also reduce mortality from both ICH and cancer. Use of qPTP significantly reduced the lifetime probability of PE diagnosis, with lower probability of death from PE in both sexes aged 40 to 60 years. However, use of qPTP reduced the rate of ACS diagnosis and death from ACS at age 40, but increased the death rate from ACS at age 60 for both sexes. CONCLUSIONS: Widespread use of a combined qPTP for both ACS and PE has the potential to decrease costs by reducing diagnostic testing, while improving most long-term outcomes in emergency patients with chest pain and dyspnea.

Research priorities for the influence of gender on diagnostic imaging choices in the emergency department setting.

Diagnostic imaging is a cornerstone of patient evaluation in the acute care setting, but little effort has been devoted to understanding the appropriate influence of sex and gender on imaging choices. This article provides background on this issue and a description of the working group and consensus findings reached during the diagnostic imaging breakout session at the 2014 Academic Emergency Medicine consensus conference "Gender-specific Research in Emergency Care: Investigate, Understand, and Translate How Gender Affects Patient Outcomes." Our goal was to determine research priorities for how sex and gender may (or should) affect imaging choices in the acute care setting. Prior to the conference, the working group identified five areas for discussion regarding the research agenda in sex- and gender-based imaging using literature review and expert consensus. The nominal group technique was used to identify areas for discussion for common presenting complaints to the emergency department where ionizing radiation is often used for diagnosis: suspected pulmonary embolism, suspected kidney stone, lower abdominal pain with a concern for appendicitis, and chest pain concerning for coronary artery disease. The role of sex- and gender-based shared decision-making in diagnostic imaging decisions is also raised.

Frequent pediatric emergency department use in infancy and early childhood.

OBJECTIVE: To define the threshold and population factors associated with pediatric emergency department (PED) use above the norm during the first 36 months of life. METHODS: We conducted a cross-sectional study of children born between 2003 and 2006, treated in a single PED within the first 36 months of life. Exclusion criteria included out-of-county residence or history of abuse or neglect. The primary outcome, frequent PED use, was defined by the 90th percentile for PED visits per patient. Multivariate analysis was used to identify factors associated with frequent PED use. RESULTS: A total of 41,912 visits occurred for 16,664 patients during the study. Pediatric ED use skewed heavily toward less than 2 visits per patient (median, 2; range, 1-39; interquartile range, 2). The threshold for frequent PED use was 5 or more visits per patient and occurred for 14% (95% confidence interval [95% CI], 13%-15%) of patients. Most visits were coded with low acuity International Classifications of Diseases, 9th Revision, Clinical Modification codes. The following factors were strongly associated with frequent PED use: lack of primary care physician (odds ratio [OR], 6.03; 95% CI, 5.39%-6.80%; P < 0.0001), non private insurance (OR, 3.64; 95% CI, 2.99%-4.46%; P<0.0001), and history of inpatient admission (OR, 3.09; 95% CI, 1.66%-2.24%; P < 0.0001). Leaving without being seen, black race, Hispanic ethnicity, and residence in a poverty-associated zip code were also significantly associated, but less strongly predictive of, frequent PED use. CONCLUSIONS: The threshold for frequent PED use was more than 5 visits per patient within the first 36 months of life. Further study is needed to better define this population and develop targeted interventions to ensure care provision occurs in the ideal setting.

N-acetylcysteine plus intravenous fluids versus intravenous fluids alone to prevent contrast-induced nephropathy in emergency computed tomography.

STUDY OBJECTIVE: We test the hypothesis that N-acetylcysteine plus normal saline solution is more effective than normal saline solution alone in the prevention of contrast-induced nephropathy. METHODS: The design was a randomized, double blind, 2-center, placebo-controlled interventional trial. Inclusion criteria were patients undergoing chest, abdominal, or pelvic computed tomography (CT) scan with intravenous contrast, older than 18 years, and at least one contrast-induced nephropathy risk factor. Exclusion criteria were end-stage renal disease, pregnancy, N-acetylcysteine allergy, or clinical instability. Intervention for the treatment group was N-acetylcysteine 3 g in 500 mL normal saline solution as an intravenous bolus and then 200 mg/hour (67 mL/hour) for up to 24 hours; and for the placebo group was 500 mL normal saline solution and then 67 mL/hour for up to 24 hours. The primary outcome was contrast-induced nephropathy, defined as an increase in creatinine level of 25% or 0.5 mg/dL, measured 48 to 72 hours after CT. RESULTS: The data safety and monitoring board terminated the study early for futility. Of 399 patients enrolled, 357 (89%) completed follow-up and were included. The N-acetylcysteine plus saline solution group contrast-induced nephropathy rate was 14 of 185 (7.6%) versus 12 of 172 (7.0%) in the normal saline solution only group (absolute risk difference 0.6%; 95% confidence interval -4.8% to 6.0%). The contrast-induced nephropathy rate in patients receiving less than 1 L intravenous fluids in the emergency department (ED) was 19 of 147 (12.9%) versus 7 of 210 (3.3%) for greater than 1 L intravenous fluids (difference 9.6%; 95% confidence interval 3.7% to 15.5%), a 69% risk reduction (odds ratio 0.41; 95% confidence interval 0.21 to 0.80) per liter of intravenous fluids. CONCLUSION: We did not find evidence of a benefit for N-acetylcysteine administration to our ED patients undergoing contrast-enhanced CT. However, we did find a significant association between volume of intravenous fluids administered and reduction in contrast-induced nephropathy.

Prospective study of the incidence of contrast-induced nephropathy among patients evaluated for pulmonary embolism by contrast-enhanced computed tomography.

OBJECTIVES: Contrast-enhanced computed tomography (CECT) of the pulmonary arteries (CTPA) has become the mainstay to evaluate patients with suspected pulmonary embolism (PE) and is one of the most common CECT imaging studies performed in the emergency department (ED). While contrast-induced nephropathy (CIN) is a known complication, this risk is not well defined in the ED or other ambulatory setting. The aim of this study was to define the risk of CIN following CTPA. METHODS: The authors enrolled and followed a prospective, consecutive cohort (June 2007 through January 2009) of patients who received intravenous (IV) contrast for CTPA in the ED of a large, academic tertiary care center. Study outcomes included 1) CIN defined as an increase in serum creatinine (sCr) of ≥ 0.5 mg/dL or ≥ 25%, 2 to 7 days following contrast administration; and 2) severe renal failure defined as an increase in sCr to ≥ 3.0 mg/dL or the need for dialysis within 45 days and/or renal failure as a contributing cause of death at 45 days, determined by the consensus of three independent physicians. RESULTS: A total of 174 patients underwent CTPA, which demonstrated acute PE in 12 (7%, 95% confidence interval [CI] = 3% to 12%). Twenty-five patients developed CIN (14%, 95% CI = 10% to 20%) including one with acute PE. The development of CIN after CTPA significantly increased the risk of the composite outcome of severe renal failure or death from renal failure within 45 days (relative risk = 36, 95% CI = 3 to 384). No severe adverse outcomes were directly attributable to complications of venous thromboembolism (VTE) or its treatment. CONCLUSIONS: In this population, CIN was at least as common as the diagnosis of PE after CTPA; the development of CIN was associated with an increased risk of severe renal failure and death within the subsequent 45 days. Clinicians should consider the risk of CIN associated with CTPA and discuss this risk with patients.

Immediate complications of intravenous contrast for computed tomography imaging in the outpatient setting are rare.

OBJECTIVES: Despite increasing attention to the long-term risks of radiation exposure and contrast-induced nephropathy (CIN), institutional guidelines and patient consent procedures for contrast-enhanced computed tomography (CECT) imaging in the emergency department (ED) setting have focused primarily on more immediate complications, directly attributable to the administration of intravenous (IV) iodinated contrast administration. Thus, this study sought to define the risk of these immediate complications with the overall aim of improving institutional guidelines and patient consent procedures. METHODS: This was a prospective, consecutive cohort study of patients undergoing CECT of any body region in the ED, for complications occurring within 1 week of contrast administration, using predefined implicit definitions. Severe complications were defined as any of the following requiring medical or surgical intervention: bronchospasm with acute respiratory failure, airway obstruction, anaphylactoid shock, or acute pulmonary edema. The development of compartment syndrome, lactic acidosis, or pulmonary edema within 1 week of contrast administration was also considered a severe complication. RESULTS: Of 633 patients, only five (0.8%, 95% confidence interval [CI] = 0.3% to 1.8%) reported any immediate complications, all of which were classified as minor. No patient developed a reaction meeting the study definition of a severe complication. CONCLUSIONS: The frequency of severe, immediate complications from CECT imaging that includes IV contrast is less than 1%, and the frequency of mild complications is less than 2%. The authors conclude that CECT is associated with a very low rate of severe immediate complications.

Incidence of contrast-induced nephropathy after contrast-enhanced computed tomography in the outpatient setting.

BACKGROUND AND OBJECTIVES: No prospective study has reported the incidence of contrast-induced nephropathy (CIN) or the associated morbidity and mortality after contrast-enhanced computed tomography (CECT) in the outpatient setting. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We enrolled and followed a prospective, consecutive cohort (June 2007 through January 2009) of patients who received intravenous contrast for CECT in the emergency department of a large, academic, tertiary care center. Outcomes measured were as follows (1) CIN: An increase in serum creatinine > or =0.5 mg/dl or > or =25% 2 to 7 d after contrast administration; (2) severe renal failure: An increase in serum creatinine to > or =3.0 mg/dl or the need for dialysis at 45 d; and (3) renal failure as a contributing cause of death (consensus of three independent physicians) at 45 d. RESULTS: The incidence of CIN was 11% (70 of 633) among the 633 patients enrolled. Fifteen (2%) patients died within 45 d, including six deaths after study-defined CIN. Seven (1%) patients developed severe renal failure, six of whom had study-defined CIN. Of the six patients with CIN and severe renal failure, four died, and adjudicators determined that renal failure significantly contributed to all four deaths. Thus, CIN was associated with an increased risk for severe renal failure and death from renal failure. CONCLUSIONS: CIN occurs in >10% of patients who undergo CECT in the outpatient setting and is associated with a significant risk for severe renal failure and death.

Tandem measurement of D-dimer and myeloperoxidase or C-reactive protein to effectively screen for pulmonary embolism in the emergency department.

OBJECTIVES: The hypothesis was that the tandem measurement of D-dimer and myeloperoxidase (MPO) or C-reactive protein (CRP) could significantly decrease unnecessary pulmonary vascular imaging in emergency department (ED) patients evaluated for pulmonary embolism (PE) compared to D-dimer alone. METHODS: The authors measured the sequential combinations of D-dimer and MPO and D-dimer and CRP in a prospective sample of ED patients evaluated for PE at two centers. Patients were followed for 90 days for venous thromboembolism (VTE, either PE or deep venous thrombosis [DVT]), which required the consensus of two of three blinded physician reviewers. RESULTS: The authors enrolled 304 patients, 22 with VTE (7%; 95% confidence interval [CI] = 5% to 10%). The sensitivity and specificity of a D-dimer alone (cutoff > or = 500 ng/mL) were 100% (95% CI = 85% to 100%) and 59% (95% CI = 53% to 65%), respectively, and was followed by pulmonary vascular imaging negative for PE in 38% (115/304; 95% CI = 32% to 44%). The combination of either a negative D-dimer, or MPO < 22 mg/dL, had a sensitivity of 100% and specificity of 73% (95% CI = 67% to 78%). Thus, tandem measurement of D-dimer and MPO would have decreased the frequency of subsequent negative pulmonary vascular imaging from 38% to 25% (95% CI of the difference of -13% = -5% to -20%). The combination of CRP and D-dimer would not have significantly improved the rate of negative imaging. CONCLUSIONS: The tandem measurement of D-dimer and MPO would have significantly decreased negative pulmonary vascular imaging compared with D-dimer alone and should be validated prospectively.

Emergency clinician-performed compression ultrasonography for deep venous thrombosis of the lower extremity.

STUDY OBJECTIVE: Emergency clinician-performed ultrasonography holds promise as a rapid and accurate method to diagnose and exclude deep venous thrombosis. However, the diagnostic accuracy of emergency clinician-performed ultrasonography performed by a heterogenous group of clinicians remains undefined. METHODS: Prospective, single-center study conducted at an urban, academic emergency department (ED). Clinician participants included ED faculty, supervised residents, and midlevel providers who completed a training course for above-calf, 3-point-compression, venous ultrasonography. Patient participants had suspected leg deep venous thrombosis and greater than or equal to 1 predefined sign or symptom. Before any imaging, clinicians classified patients as low (<15%), moderate (15% to 40%), or high (>40%) pretest probability of deep venous thrombosis, followed by emergency clinician-performed ultrasonography. A whole-leg reference venous ultrasonography was then performed and interpreted separately in the radiology department. Patients were followed for 30 days. The criterion standard for deep venous thrombosis(+), required thrombosis of any leg vein on a reference ultrasonograph and clinical plan to treat. RESULTS: We enrolled 183 patients, and 27 (15%) had deep venous thrombosis(+). The sensitivity and specificity emergency clinician-performed ultrasonography was 70% (95% confidence interval [CI] 60% to 80%) and 89% (95% CI 83% to 94%), respectively, with overall diagnostic accuracy of 85% (95% CI 79% to 90%). The posterior probability of deep venous thrombosis(+) among the 88 low-risk patients with a negative emergency clinician-performed ultrasonographic result was 1 of 88, or 1.1% (95% CI 0% to 6%), and the posterior probability of deep venous thrombosis(+) among 14 high-risk patients with a positive emergency clinician-performed ultrasonographic result was 11 of 14, or 79% (95% CI 49% to 95%). CONCLUSION: The overall diagnostic accuracy of single-visit emergency clinician-performed ultrasonography performed by a heterogeneous group of ED clinicians is intermediate but may be improved by pretest probability assessment.

Systematic bias introduced by the informed consent process in a diagnostic research study.

OBJECTIVES: To determine population characteristics, outcomes, and reasons for unsuccessful enrollment among potential study subjects approached for written, informed consent in a minimal-risk emergency department (ED) study. The authors hypothesized that the prevalence of venous thromboembolism (VTE) would be lower among study participants and that medical acuity and refusal to provide a blood sample would be the most common reasons for nonparticipation. METHODS: The authors requested prospective, written, informed consent for a blood sample and follow-up from consecutive ED patients undergoing evaluation for pulmonary embolism (PE) and recorded spontaneously stated reasons for refusal. VTE was diagnosed or excluded using a combination of D-dimer testing and selective computed tomography (CT) angiography of the chest with venography of the lower extremities. The primary outcome was defined by the number of CT scans positive for VTE among ED patients evaluated for PE. RESULTS: Over 16 weeks, 260 of 287 (91%, 95% confidence interval [CI] = 87 to 94%) eligible patients were approached and consent was obtained from 183 patients (64%, 95% CI = 58% to 69%). The prevalence of VTE was 6% among participants and 13% among nonparticipants (95% CI [of the difference] = 1% to 15%). The proportions of African Americans, uninsured, and Medicaid patients were significantly higher among nonparticipants. No significant differences were found in the proportions of nonparticipants who disliked or distrusted research or desired financial reimbursement, compared to those not enrolled due to medical acuity or refused a blood sample. CONCLUSIONS: These data implicate the written, informed consent process as a significant source of bias on estimated disease prevalence.

Direct comparison of the diagnostic accuracy of fifty protein biological markers of pulmonary embolism for use in the emergency department.

OBJECTIVES: Pulmonary embolism (PE) is associated with abnormal concentrations of many proteins involved in inflammation, hemostasis, and vascular injury. The authors quantified the diagnostic accuracy of a battery of protein biological markers for the detection of PE in emergency department (ED) patients. METHODS: A random and a consecutive sample of ED patients evaluated for PE were prospectively enrolled at two academic EDs between August 2005 and April 2006. A plasma sample was obtained at enrollment, and all patients were followed by telephone and medical record review at 90 days for the development of venous thromboembolism (VTE) defined as PE or deep venous thrombosis (DVT), requiring the consensus of two of three blinded physician reviewers. Measurements of potential biological markers were performed by technicians blinded to the study objectives. The diagnostic accuracy of each biological marker was determined by the area under the receiver operating characteristic (ROC) curve. RESULTS: Fifty potential biological markers were measured in 304 ED patients, including 22 patients (7%, 95% confidence interval [CI] = 4% to 10%) with VTE. Fourteen biological markers demonstrated an area under the curve (AUC) with the lower limit of the 95% CI > or = 0.5. Of these, three demonstrated an AUC > or = 0.7: D-dimer (0.90), C-reactive protein (CRP; 0.78), and myeloperoxidase (MPO; 0.78). CONCLUSIONS: From 50 candidate biological markers, only D-dimer, CRP, and MPO demonstrated sufficient diagnostic accuracy to suggest potential utility as biological marker of PE.

Prospective study of the diagnostic accuracy of the simplify D-dimer assay for pulmonary embolism in emergency department patients.

OBJECTIVE: To determine if a d-dimer assay (Simplify D-dimer; Agen Biomedical; Brisbane, Australia) can reliably exclude pulmonary embolism (PE) by producing a posttest probability of PE < 1% in low-risk, symptomatic emergency department (ED) patients. METHODS: Hemodynamically stable patients were evaluated for PE using a structured d-dimer-centered protocol; d-dimer testing was performed prior to imaging. Prior to testing, physicians completed an electronic data form that included their unstructured clinical estimate for the pretest probability of PE (< 15%, 15 to 40%, or > 40%) and the elements of the Charlotte rule and Canadian score for PE. Criterion standard was selective use of pulmonary vascular imaging and 90-day follow-up. RESULTS: We enrolled 2,302 patients (mean age, 45 +/- 16 years [+/- SD]; 31% male); 108 patients received a diagnosis of PE (4.7%; 95% confidence interval [CI], 3.6 to 5.6%). The overall sensitivity and specificity of the d-dimer assay were 80.6% (95% CI, 71.8 to 87.5%) and 72.5% (95% CI, 70.6 to 74.4%), respectively. The negative likelihood ratio and negative predictive value were 0.27 (95% CI, 0.18 to 0.39) and 98.7% (95% CI, 98.0 to 99.1%), respectively. The posttest prevalence of PE among low-risk patients with negative d-dimer results was 0.7% (95% CI, 0.3 to 1.4%) for the unstructured estimate, 1.2% (95% CI, 0.7 to 2.0%) for the Canadian score, and 1.1% (95% CI, 0.6 to 1.7%) for the Charlotte rule. CONCLUSIONS: The Simplify D-dimer assay had moderate sensitivity and relatively high specificity for PE in low-risk ED patients. The combination of a physician's unstructured estimate of pretest probability of PE of < 15% and a negative d-dimer result produced a posttest probability of PE of 0.7% (95% CI, 0.3 to 1.4%).