Risk of thrombosis with thrombocytopenia syndrome after COVID‐19 vaccination prior to the recognition of vaccine‐induced thrombocytopenia and thrombosis: A self‐controlled case series study in England

Background

Objectives

Methods

Results

Conclusions

Methodology for sampling women at high maternal risk in administrative data

Background

In population level studies, the conventional practice of categorizing women into low and high maternal risk samples relies upon ascertaining the presence of various comorbid conditions in administrative data. Two problems with the conventional method include variability in the recommended comorbidities to consider and inability to distinguish between maternal and fetal risks. High maternal risk sample selection may be improved by using the Obstetric Comorbidity Index (OCI), a system of risk scoring based on weighting comorbidities associated with maternal end organ damage. The purpose of this study was to compare the net benefit of using OCI risk scoring vs the conventional risk identification method to identify a sample of women at high maternal risk in administrative data.

Methods

This was a net benefit analysis using linked delivery hospitalization discharge and vital records data for women experiencing singleton births in Georgia from 2008 to 2012. We compared the value identifying a sample of women at high maternal risk using the OCI score to the conventional method of dichotomous identification of any comorbidities. Value was measured by the ability to select a sample of women designated as high maternal risk who experienced severe maternal morbidity or mortality.

Results

The high maternal risk sample created with the OCI had a small but positive net benefit (+ 0.6), while the conventionally derived sample had a negative net benefit indicating the sample selection performed worse than identifying no woman as high maternal risk.

Conclusions

The OCI can be used to select women at high maternal risk in administrative data. The OCI provides a consistent method of identification for women at risk of maternal morbidity and mortality and avoids confounding all obstetric risk factors with specific maternal risk factors. Using the OCI may help reduce misclassification as high maternal risk and improve the consistency in identifying women at high maternal risk in administrative data.

Associations Between Hospital Maternal Service Level and Delivery Outcomes

OBJECTIVE

This study explored the associations between delivery hospital self-reported level of maternal service, as defined by the American Hospital Association, and both maternal and neonatal outcomes among women at high maternal risk, as defined by the Obstetric Comorbidity Index.

METHODS

This was a secondary analysis of linked delivery hospitalization discharge and vital records data for women experiencing singleton births in Georgia from 2008 to 2012. The need for maternal transfer was defined using a sample-specific cut-off of the risk score calculated using the Obstetric Comorbidity Index. Outcomes included poor maternal outcome (severe maternal morbidity or death), maternal length of stay, preterm delivery, low birth weight, and perinatal death. The analysis was completed using hierarchical logistic regression with a two-level model considering hospital level of maternal service and controlling for maternal race and transfer status.

RESULTS

In these data, there was no difference in the odds of a poor maternal or neonatal outcome according to delivery hospital level of maternal care; however, delivery at a hospital with maternal service level III was associated with a higher odds of an extended length of stay.

CONCLUSIONS

For this group of pregnant women in need of maternal transfer, delivery hospital self-reported level of maternal care was not associated with the odds of poor maternal or neonatal outcomes. This study supports the need for improved definitions of hospital level of maternal services.

Growing a Robust Academic Practice Partnership in an Academic Health System

Schools of nursing located within academic health centers have embraced expanded opportunities to lead in this era of rapid change and considerable uncertainty in US health care. These schools bear a unique responsibility to work with their clinical nursing partners to advance the care of patients, improve the health of communities and populations, and help steward the nation's health care resources. This article describes how the Emory University Nell Hodgson Woodruff School of Nursing has formed and sustained academic-practice partnerships in response to these imperatives. The structures and processes that have supported the partnerships are shared, as are the keys to success in a true partnership. The authors describe the work required to achieve mutually agreed-upon goals, along with the challenges that faculty and health care leaders have faced in their journey to system partnerships.

Post thrombotic syndrome following deep vein thrombosis in paediatric patients

Background Although well characterised in adults, less is known about post-thrombotic syndrome in children. In this review, current knowledge regarding paediatric post-thrombotic syndrome is summarised, with particular emphasis on pathophysiology, aetiology, diagnosis and management. Methods A Medline literature review was performed using search terms 'post thrombotic syndrome', 'post phlebitic syndrome', paediatric and children. Relevant articles were identified and included for summation analysis. Results The incident of paediatric venous thromboembolism is rising. Deep vein thrombosis can cause venous hypertension through a combination of venous reflux, venous obstruction and impairment of the calf muscle pump, leading to development of post-thrombotic syndrome. In children, this is more likely to occur if deep vein thrombosis diagnosis and treatment are delayed, if a higher number of vessels are involved, and if factors such as D-dimer are elevated at diagnosis and throughout treatment. Post-thrombotic syndrome occurs in about 26% of paediatric deep vein thrombosis, though the results of individual studies vary widely. A number of tools exist to diagnose paediatric post-thrombotic syndrome, including the modified Villalta scale and Manco-Johnson instrument. Once post-thrombotic syndrome develops, the mainstay of treatment remains supportive, with little evidence of benefit from pharmacological measures. Conclusion Surgical or interventional treatment is not advised except in exceptional cirumstances, due to variable prognosis of PTS in paediatric populations with rising incidence of paediatric venous thromboembolism, it follows that the prevalence of post-thrombotic syndrome in children may also increase. Evidence-based venous thromboembolism prevention strategies need to be implemented for prevention of deep vein thrombosis, but when it does occur, deep vein thrombosis requires prompt and effective treatment to prevent post-thrombotic syndrome. Optimum treatment strategies for post-thrombotic syndrome require further investigation.

Predictors of Patient Satisfaction With Telephone Nursing Services

Patient satisfaction has been shown to be a factor in clinical outcomes, health care quality, and patient follow-through. Thus, a high level of satisfaction is a desired outcome of patient care. This article examines predictors of patient satisfaction with telephone nursing services among a sample of 1,939 respondents, using a conceptual model derived from the literature and preliminary work. The study was conducted in medical offices and call centers of a large national health maintenance organization. Calls were taped and content coded and then matched with caller questionnaire data. In the final multivariate predictive models, patient health status; caller ratings of expectations met by the nurse for listening, clarity, and collaboration; and nurse competence were the strongest predictors of satisfaction. Consistent with the literature, findings suggest that nurses should expand interpersonal communication skills, and systems should reduce barriers to effective listening, clarity, and collaboration with callers.

Predicting Patient Follow-Through on Telephone Nursing Advice

Although use of telephone advice nursing services continues to grow, little research has addressed factors that affect crucial call outcomes like follow-through on the advice given. This article describes aspects of the advice call process and examines predictors of caller follow-through, using a conceptual model derived from the literature and the authors' preliminary work. Calls to call centers and medical offices of a large health maintenance organization were taped, then content was coded and matched with caller questionnaire (CQ) data. Out of 1,863 participants, 1,489 reported following all the advice. In the final multivariate predictive model, statistically significant predictors of follow-through were patient health status, caller's rating of nurse helpfulness, and the extent to which caller expectations for collaboration were met and the caller understood the advice given. Results suggest that nurses should receive continuous training on effective communication techniques, and advice nurse performance standards that create barriers to communication should be modified.

Clinical Decision Rules as Tools for Evidence-Based Nursing

Nursing practice is fraught with uncertainty and our patients do not always respond predictably to our interventions. Properly developed and tested Clinical Decision Rules (CDRs), a special type of decision support tool, help organize research evidence into standardized patient assessments and treatments, thereby increasing the probability of attaining the desired outcome and reducing uncertainty in practice. The purpose of this article is to examine CDRs as one kind of decision support tool that can be used to facilitate nursing decision making and evidence-based practice (EBP). CDRs differ from both treatment algorithms and clinical pathways in the ways they are developed and in their scope of applicability. CDRs are developed using strict methodological standards, with the goal that they function well when used by a variety of care providers, with various patient populations, and in different patient care settings.

Guidelines for Developing and Testing Clinical Decision Rules

Clinical decision rules (CDRs) are decision support tools that synthesize evidence for use in bedside practice. They differ from other decision support tools in the methodological rigor with which they are developed. This article describes the important considerations in developing a CDR, including identifying the need for the rule, carefully defining the outcome variable, identifying and selecting the possible predictor variables, and guidelines for initial testing of the CDR. The process of developing and testing CDRs is best undertaken by teams of researchers, with clinical nurses providing important input in both the development and testing. It's important that clinical nurses understand both the contributions of CDRs and their inherent limitations, as appropriate use of well-developed, well-validated CDRs will become more and more a necessity in evidence-based nursing.

Blood Glucose Levels of Patients With Diabetes in the Immediate Post-Acute Hemodialysis Period: An Exploratory Study

PROBLEM/PURPOSE: To establish the evidence on which to base a protocol for monitoring capillary blood glucose in hospitalized patients with diabetes mellitus in the immediate post-acute hemodialysis period.

SAMPLE

Hospitalized, non-critically ill, adult patients (n = 68) with diabetes undergoing acute hemodialysis treatments.

METHODS

Capillary blood glucose was tested 30 minutes prior to the end of the hemodialysis treatment, at the end of the treatment, and 30 minutes and 60 minutes post-treatment. Data were analyzed to determine both within and between patient variability.

RESULTS

Glucose levels varied widely before, during, and after hemodialysis, with greatest variability at 60 minutes post-hemodialysis. Levels did not vary based on diabetes type or admitting diagnosis. Possible relationships were identified with length of treatment, insulin administration prior to treatment, and food consumed within an hour after treatment. CONCLUSIONS/NURSING IMPLICATIONS: Testing post-dialysis glucose levels earlier than 60 minutes post-treatment may miss the need for additional medication.

The von Willebrand factor predicted unpaired cysteines are essential for secretion

BACKGROUND

von Willebrand factor (VWF) contains free thiols that mass spectroscopy has located to nine cysteines: two in the D3 domain (Cys889 and Cys898) and seven in the C domains (Cys2448, Cys2451, Cys2453, Cys2490, Cys2491, Cys2528, and Cys2533) (J Biol Chem, 7, 2007, 35604; Blood, 118, 5312). It has been suggested that these free thiols function to regulate the self-association of VWF through thiol-disulfide exchange (J Biol Chem, 7, 2007, 35604; Blood, 118, 5312). However, recent structural modeling has predicted that these cysteines are, in fact, disulfide-bonded (Blood, 118, 5312; Blood, 120, 449).

OBJECTIVES

To use mutation and expression analyses to investigate how these conflicting reports might be compatible with the synthesis and expression of VWF.

METHODS AND RESULTS

Both full-length VWF and VWF fragments with cysteine to alanine mutations of the nine cysteines and two predicted binding partners (Cys2431 and Cys2468) failed to secrete. Mutation of a cysteine pair, C2431A/C2453A, similarly resulted in a failure to secrete, indicating that this is not secondary to creation of an unpaired thiol. Deletion mutants containing seven of these cysteines, conforming to hypothesized domain boundaries, also failed to secrete: ∆C1C6 (2255-2720), ∆C3C4 (2429-2577), ∆C3 (2429-2496), and ∆C4 (2497-2577). Analysis of cell lysates and immunofluorescence confirmed that the mutants were retained within the endoplasmic reticulum (ER). Coexpression with wild-type VWF rescued secretion of some mutants to a limited extent.

CONCLUSIONS

These data suggest: first, that pairing of cysteines implicated in free thiol exchange is essential for correct folding of the VWF molecule, and unpairing must occur following exit from the ER or secretion from the cell; and second, that intact C domains are essential for efficient VWF secretion and must interact in the ER.

Clinical phenotype, laboratory features and genotype of 35 patients with heritable dysfibrinogenaemia

Heritable dysfibrinogenaemia (HD) is a rare qualitative disorder of fibrinogen (FGN). To better describe the clinical, laboratory and genotypic spectrum of HD, we evaluated 35 subjects identified at two UK centres using laboratory criteria. 12/35(34%) subjects with HD experienced bleeding (bleeding score >1 at any site), 3/35(9%) thrombosis and 20/35(57%) were asymptomatic. Amongst subjects with bleeding, symptoms were typically mild, at one anatomical site and seldom occurred after invasive procedures. All subject showed dry clot weight within or above laboratory reference interval (median 3·2 g/l; range 1·9-5·1), reduced Clauss fibrinogen (median 0·52 g/l; range 0·21-1·3), and prolonged thrombin (median 30·7 s; range 21·3-45·7) and reptilase (median 42·0 s; range 20·0-68·0) times. In all subjects, the prothrombin time ratio (PTR), determined by Sysmex CA-1500 coagulometer and Innovin activator, was abnormal (median 1·42; range 1·22-1·61). The activated partial thromboplastin time ratio and PTR with other coagulometers and activators were comparatively insensitive to HD. All subjects with HD harboured heterozygous candidate nucleotide variations within known hotspots in the FGN genes. The HD variants identified in this cross-sectional study seldom have significant clinical manifestations and show similar laboratory features irrespective of genotype. Selection of coagulometer and PT activator may markedly affect the detection of new HD cases using coagulation screening tests.

Impact of an interactive online nursing educational module on insulin errors in hospitalized pediatric patients

OBJECTIVE

To determine the effectiveness of an online module for reducing insulin administration errors by nurses caring for hospitalized pediatric patients.

RESEARCH DESIGN AND METHODS

Pediatric nursing staff completed a mandatory online educational module teaching insulin pharmacokinetics and the insulin order form, using diluted insulin and finishing with 15 interactive cases. A chart audit to determine all possible insulin errors of patients receiving insulin was done before and 2-6 months after the educational module.

RESULTS

All of the medical center's 283 pediatric nurses successfully completed the educational module. A total of 24 charts were audited in the preintervention phase and 22 in the postintervention phase. The preintervention insulin error rate was 14.8%, reduced to 1.7% (P < 0.001) postintervention. Improvement occurred in correct insulin dosing and type, timing of administration, and timely blood glucose monitoring and documentation.

CONCLUSIONS

An interactive online educational module can be an effective strategy for reducing pediatric nurses' insulin administration errors.

Determining Severe Respiratory Distress in Older Out-of-Hospital Patients

OBJECTIVES

This preliminary investigation represents the first step in developing a clinical decision rule (CDR) to assist out-of-hospital providers in caring for older patients in respiratory distress. The specific aims of the study were: 1) to identify up to ten candidate clinical indicators of severe respiratory distress in older out-of-hospital patients and 2) to determine the feasibility of obtaining data on these indicators from out-of-hospital treatment records, and of obtaining a measure of severe respiratory distress from the emergency department (ED) medical record.

METHODS

This mixed-methods study included a qualitative component to list possible clinical indicators of severe respiratory distress, and a Delphi survey N = six experts) to reduce the comprehensive list that resulted (aim 1). The feasibility of gathering clinical indicators and a measure of severe distress was evaluated using a retrospective chart review (N = 640) of out-of-hospital and ED medical records (aim 2).

RESULTS

Nine clinical indicators were identified: level of consciousness/mentation, inability to speak in full sentences, position of the patient on arrival, decreased oxygen saturation, accessory muscle use, dyspnea, increased respiratory effort, altered respiratory rate, and retractions. There were sufficient data available on all indicators except dyspnea and retractions; a measure of severe distress was readily obtained from the ED medical record.

CONCLUSION

Medical record data were available on seven out-of-hospital clinical indicators and an ED measure of severe distress. Further work needs to be done to refine the operational definitions of the indicators and to standardize the way they are documented in the out-of-hospital medical record.

Evaluating clinical decision rules

Clinical decision rules (CDRs) are decision support tools that synthesize evidence into bedside tools for practice. Before adopting CDRs into practice, nurses must be assured that there is sufficient evidence in the literature that the rule performs as expected, can do so in a variety of settings (especially in settings similar to one's own), and that using it will likely result in improved patient outcomes at no additional cost (or conversely, that it will lower costs with no adverse effect on clinical outcomes). This article provides a framework for clinical nurses to evaluate CDRs. The framework focuses on the processes used to establish the external validity of the rule, and the evidence that using the rule results in improved patient or systems outcomes, including cost-effectiveness. The Braden Scale is used as an example and is evaluated using the framework described.

Assessing pesticide safety knowledge among Hispanic migrant farmworkers in Oregon

The purpose of this article is to report on the development and initial use of a pesticide knowledge test (PKT) specifically designed to evaluate agricultural workers' knowledge of the content mandated by the federal Worker Protection Standard (WPS). The PKT is a 20-item, true-false test, used in a sample of 414 adult and adolescent migrant farmworkers in Oregon. The overall mean score, i.e., number correct, was 15.67(78.4%), with both adults and adolescents demonstrating the most difficulty with questions related to the overall health effects of pesticides. The internal consistency was 0.73, when estimated using a method to correct for small sample sizes. Only six items had less than 70% correct answers. Content validity was achieved by basing the items directly on the Worker Protection Standard; face validity was obtained by having the final version of the test reviewed by a bilingual (English-Spanish) educator familiar with the requirements of the WPS. Overall, adult participants scored better than adolescents, and those with previous pesticide training scored better than those without. There were no differences in scores based on gender or whether the test was taken in English or Spanish; however, participants who spoke indigenous languages scored significantly lower than those who did not. These results indicate that the PKT is a valid, reliable measure of worker knowledge of the content of the WPS, although it does not measure the extent to which that knowledge is actually used in the work setting.

Telephone advice nursing services in a US health maintenance organization

We studied telephone advice nursing (TAN) in the US. We recorded 4269 TAN calls in four regions served by Kaiser Permanente, a health maintenance organization. A call description form was used to record information regarding both calls and callers. The mean call length was 5.9 min (SD 3.6, range 0.3-35.8); 300 calls lasted less than 2 min. The mean call length differed significantly across regions, from 4.4 min in Hawaii to 8.7 min in Southern California. Calls to call centres lasted an average of 6.5 min (SD 3.8), compared with 4.2 min (SD 2.9) for those to medical offices. These differences were significant. Although 42% of calls required some further medical management, only 18% (n = 754) resulted in an urgent disposition, and only 16% (n = 121; 3% of all calls) of the urgent dispositions involved referral to emergency services. The likelihood of urgent disposition varied significantly by region. Callers generally used the TAN services for the right reasons, that is, with questions or concerns that could be reasonably handled by telephone advice nurses.

SARS update: Winter, 2003 to 2004

Transmission of severe acute respiratory syndrome (SARS) related coronavirus (CoV) appears to be heterogeneous. Most transmission occurs through large droplets, but there is some evidence of spread through aerosol transmission. Proper use of personal protective equipment (PPE) and scrupulous attention to hand hygiene are critical to reducing transmission of SARS, especially in health care facilities. Surgical masks have been shown to be highly effective in reducing transmission when N-95 respirators are unavailable. Health care workers bore a large burden of illness during the 2002 to 2003 SARS epidemic. Occupational health nurses working in health care agencies will play a key role in preparing for a re-emergence of the disease. Occupational health nurses should "bookmark" the Centers for Disease Control and Prevention website for Public Health Guidance for Community-Level Preparedness and Response to SARS: www.cdc.gov/ncidod/sars/clinicalguidance.htm for easy retrieval and reference.

Factor analysis of Gulf War illness: what does it add to our understanding of possible health effects of deployment?

The authors conducted factor analysis on survey data from 1,779 Persian Gulf War veterans. Their purposes were to: 1) determine whether factor analysis identified a unique "Gulf War syndrome" among veterans potentially exposed to chemical warfare agents; 2) compare the findings of factor analysis with those from an epidemiologic analysis of symptom prevalence; and 3) observe the behavior of factor analysis when performed on dichotomous data. The factor analysis identified three factors, but they were not unique to any particular deployment group. A unique pattern of illness was not found for the larger group of veterans potentially exposed to chemical warfare agents; however, veterans who had witnessed the demolition of chemical warfare agents at the Khamisiyah site in Iraq had a greater prevalence of dysesthesia. An analysis of the performance of dichotomous variables in factor analysis showed that the standard criteria used to determine the number of relevant factors and the dominant variables within them may be inappropriate. While Gulf War veterans appear to suffer an increased burden of illness, there is insufficient evidence to identify a unique syndrome in this population of deployed servicemen and women. Furthermore, the results provide evidence that factor analysis may make a limited contribution in this area of research.

Telemedicine for the Medicare population: pediatric, obstetric, and clinician-indirect home interventions

BACKGROUND

This report is a supplement to an earlier evidence report, Telemedicine for the Medicare Population, which was intended to help policymakers weigh the evidence relevant to coverage of telemedicine services under Medicare. That report focused on telemedicine programs and clinical settings that had been used with or were likely to be applied to Medicare beneficiaries. While we prepared that report, it became apparent that there are also telemedicine studies among non-Medicare beneficiaries--e.g., children and pregnant women--that could inform policymakers and provide more comprehensive evidence of the state of the science regarding telemedicine applications. In addition, the first evidence report only partially included a class of telemedicine applications (called self-monitoring/testing telemedicine) in which the beneficiary used a home computer or modern-driven telephone system to either report information or access information and support from Internet resources and indirectly interact with a clinician. Self-monitoring/testing applications in the first report required direct interaction with a clinician. The goal of this report is to systematically review the evidence in the clinical areas of pediatric and obstetric telemedicine as well as home-based telemedicine where there is indirect involvement of the health care professional. (In this report, we will refer to the latter as clinician-indirect home telemedicine.) Specifically, the report summarizes scientific evidence on the diagnostic accuracy, access, clinical outcomes, satisfaction, and cost-effectiveness of services provided by telemedicine technologies for these patient groups. It also identifies gaps in the evidence and makes recommendations for evaluating telemedicine services for these populations in the future. The evidence is clustered according to three categories of telemedicine service defined in our original report: store-and-forward, self-monitoring/testing, and clinician-interactive services. The three clinical practice areas reviewed in this report are defined as follows. The term pediatric applies to any telemedicine study in which the sample consisted wholly or partially of persons aged 18 or younger, including studies with neonatal samples. The term obstetric applies to any telemedicine study in which the sample consisted entirely of women seeking pregnancy-related care. The term clinician-indirect home telemedicine applies to home-based telemedicine (called self-monitoring/testing in our original report) where a telemedicine application used in the home has only indirect involvement by the health care professional. Interactive home telemedicine was applied in this report to all patient populations.

KEY QUESTIONS

The key questions that served as a guide for reviewing the literature in the evaluation of pediatric, obstetric, and clinician-indirect home telemedicine applications were derived by consensus among the evidence-review team based on the analytic framework established for the original evidence report. For the current report, the questions were applied to studies in all three practice areas as a whole group within each of the three categories of telemedicine services: store-and-forward; self-monitoring/testing; and clinician-interactive. The specific key questions were: 1. Does telemedicine result in comparable diagnosis and appropriateness of recommendations for management? 2. Does the availability of telemedicine provide comparable access to care? 3. Does telemedicine result in comparable health outcomes? 4. Does telemedicine result in comparable patient or clinician satisfaction with care? 5. Does telemedicine result in comparable costs of care and/or cost-effectiveness?

METHODS

We searched for peer-reviewed literature using several bibliographic databases. In addition, we conducted hand searches of leading telemedicine journals and identified key papers from the reference lists of journal articles. For our original evidence report on telemedicine for the Medicare population, we designed a search to find any publications about telemedicine and used it to search the MEDLINE, CINAHL, and HealthSTAR databases for all years the databases were available. Through this process, we captured studies of pediatric, obstetric, and clinician-indirect home telemedicine; however, they were excluded from the original report since they were outside its scope. For this supplemental report, we reviewed our original search results and identified studies relevant to this report. We identified additional studies from the reference lists of included papers and from hand searching two peer-reviewed telemedicine publications, the Journal of Telemedicine and Telecare and Telemedicine Journal. We critically appraised the included studies for each study area and key question and discussed the strengths and limitations of the most important studies at weekly meetings of the research team. We also developed recommendations for research to address telemedicine knowledge gaps. To match these gaps with the capabilities of specific research methods, we classified the telemedicine services according to the type of evidence that would be needed to determine whether the specific goals of covering such services had been met. We emphasized the relationship between the type and level of evidence found in the systematic review of effectiveness and the types of studies that might be funded to address the gaps in knowledge in this growing field of research.

FINDINGS

We identified a total of 28 eligible studies. In the new clinical areas, we found few studies in store-and-forward telemedicine. There is some evidence of comparable diagnosis and management decisions made using store-and-forward telemedicine from the areas of pediatric dental screening, pediatric ophthalmology, and neonatalogy. In self-monitoring/testing telemedicine for the areas of pediatrics, obstetrics, and clinician-indirect home telemedicine, there is evidence that access to care can be improved when patients and families have the opportunity to receive telehealth care at home rather than in-person care in a clinic or hospital. Access is particularly enhanced when the telehealth system enables timely communication between patients or families and care providers that allows self-management and necessary adjustments that may prevent hospitalization. There is some evidence that this form of telemedicine improves health outcomes, but the study sample sizes are usually small, and even when they are not, the treatment effects are small. There is also some evidence for the efficacy of clinician-interactive telemedicine, but the studies do not clearly define which technologies provide benefit or cost-efficiency. Some promising areas for diagnosis include emergency medicine, psychiatry, and cardiology. Most of the studies measuring access to care provide evidence that it is improved. Although none of these studies were randomized controlled trials, they provide some evidence of access improvement over prior conditions. Clinician-interactive telemedicine was the only area for which any cost studies were found. The three cost studies did not adequately demonstrate that telemedicine reduces costs of care (except comparing only selected costs). No study addressed cost-effectiveness.

CONCLUSIONS

This supplemental report covering the areas of pediatrics, obstetrics, and indirect-clinician home telemedicine echoes the findings of our initial report for the Medicare domain, which is that while the use of telemedicine is small but growing, the evidence for its efficacy is incomplete. Many of the studies are small and/or methodologically limited, so it cannot be determined whether telemedicine is efficacious. Future studies should focus on the use of telemedicine in conditions where burden of illness and/or barriers to access for care are significant. Use of recent innovations in the design of randomized controlled trials for emerging technologies would lead to higher quality studies. Journals publishing telemedicine evaluation studies must set high standards for methodologic quality so that evidence reports need not rely on studies with marginal methodologies.

Disparity detection in anticorrelated stereograms

Recent physiological observations in which stimuli with opposite contrast signs in the two eyes have been used (anticorrelated stereograms) show that these stimuli evoke responses in primary visual cortex which are the reverse of responses to correlated stimuli. Psychophysical investigations reveal no such reversals: reversed-contrast bars with crossed disparities are seen in front of those with uncrossed disparities. For anticorrelated random-dot stereograms human subjects perceive no depth at all, except at low dot densities. However, these human studies were carried out with stimuli that differed in several ways from those used in physiological studies. We therefore reexamined psychophysical responses using stimuli similar to those used for physiological recordings. Our results confirm the previous findings: there is no evidence of a reversed depth sensation for bar stereograms (crossed disparities are never seen behind uncrossed disparities), and subjects are unable to detect depth in anticorrelated random-dot stereograms at the densities used for the physiological recordings. The discrepancy between the psychophysical data and the responses of single neurons in primary visual cortex suggests that further processing outside area V1 is necessary to provide the signals that produce the sensation of stereoscopic depth.

Infections following implant arthroplasties of the forefoot

This article discusses the causes, pathogenesis, diagnosis, prevention, and treatment of infections associated with implant arthroplasties of the forefoot. Topics covered include isolated organisms, routes of infection, bacterial glycocalyx (that is, biofilm or slime layer) production, preoperative evaluation, air filtration systems, surgical technique, use of prophylactic antibiotics, inflammatory reactions (arthritic detritus, metallosis), differential diagnosis, and treatment protocols.

Right atrial myxoma with right to left shunting and mitral valve prolapse

A 58 year old black man presented with progressive dyspnea and persistent systemic arterial hypoxemia. Initial hemodynamic evaluation revealed mitral valve prolapse and evidence for isolated right to left shunting, presumed to be extracardiac. A detailed pulmonary evaluation disclosed normal volume and flow parameters with a mild reduction of the single breath carbon monoxide diffusing capacity. An open lung biopsy disclosed no abnormalities. Radionuclide studies of the heart, however, suggested the possibility of a filling defect in the right atrium, and echocardiography enforced the impression of a mass in the right atrium, subsequently demonstrated by superior vena cava angiography. Our report outlines the use of multiple diagnostic tools in difficult situations and stresses the importance of right atrial myxoma in the differential diagnosis of isolated right to left shunting