The role of before-after studies of therapeutic impact in the evaluation of diagnostic technologies

Factors influencing the clinical adoption of quantitative gait analysis technology with a focus on clinical efficacy and clinician perspectives: A scoping review

INTRODUCTION

Quantitative gait analysis (QGA) has the potential to support clinician decision-making. However, it is not yet widely accepted in practice. Evidence for clinical efficacy (i.e., efficacy and effectiveness), as well as a users' perspective on using the technology in clinical practice (e.g., ease of use and usefulness) can help impact their widespread adoption.

OBJECTIVE

To synthesize the literature on the clinical efficacy and clinician perspectives on the use of gait analysis technologies in the clinical care of adult populations.

METHODS

This scoping review followed the Joanna Briggs Institute (JBI) methodology for scoping reviews. We included peer-reviewed and gray literature (i.e., conference abstracts). A search was conducted in MEDLINE (Ovid), CENTRAL (Ovid), EMBASE (Ovid), CINAHL (EBSCO) and SPORTDiscus (EBSCO). Included full-text studies were critically appraised using the JBI critical appraisal tools.

RESULTS

A total of 15 full-text studies and two conference abstracts were included in this review. Results suggest that QGA technologies can influence decision-making with some evidence to suggest their role in improving patient outcomes. The main barrier to ease of use was a clinician's lack of data expertise, and main facilitator was receiving support from staff. Barriers to usefulness included challenges finding suitable reference data and data accuracy, while facilitators were enhancing patient care and supporting clinical decision-making.

SIGNIFICANCE

This review is the first step to understanding how QGA technologies can optimize clinical practice. Many gaps in the literature exist and reveal opportunities to improve the clinical adoption of gait analysis technologies. Further research is needed in two main areas: 1) examining the clinical efficacy of gait analysis technologies and 2) gathering clinician perspectives using a theoretical model like the Technology Acceptance Model to guide study design. Results will inform research aimed at evaluating, developing, or implementing these technologies.

FUNDING

This work was supported by the Walter and Maria Schroeder Institute for Brain Innovation and Recovery and AGE-WELL Graduate Student Award in Technology and Aging [2021,2022].

Influence of cone beam computed tomography on endodontic treatment planning: A systematic review

OBJECTIVES

The aim of this systematic review was to evaluate how treatment plans changed when cone beam computed tomography (CBCT) imaging was used in endodontic treatment decision-making.

DATA

Studies examining changes in clinicians' treatment plans with and without the use of CBCT were included. Risk of bias assessment was completed using a modification of the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool.

SOURCES

A systematic search was performed in PubMed, Embase, Scopus, Cochrane databases from inception to 14 September 2021.

STUDY SELECTION

The initial search identified 3379 titles and abstracts; 20 articles fulfilled inclusion and exclusion criteria for full text review. An additional three articles were identified through citation searching. Sixteen studies met inclusion and exclusion criteria for data extraction and analysis. Fifteen studies reported changes in treatment plan with CBCT imaging. Five studies reported changes in 45 - 66.7% of the cases but did not mention specific treatment options. Of the 11 remaining studies, 10 studies reported changes in 24.3 - 56% of cases and changes in treatment options, while one study reported no significant change in treatment plan after CBCT imaging was introduced. With CBCT imaging, clinicians were more likely to prescribe further intervention that included endodontic treatment and extractions.

CONCLUSION

Although the current evidence was heterogeneous, it was clear that CBCT offered more information than periapical radiography. This influenced endodontic treatment decision-making and in more complex cases, led to further intervention including non-surgical and surgical endodontic treatment and extractions.

CLINICAL SIGNIFICANCE

Additional information from CBCT imaging influenced endodontic treatment decision-making in the following situations: high difficulty cases, diagnosis of symptomatic teeth after failed root canal treatment, evaluation of periapical healing, pre-surgical treatment planning, and management of traumatised immature teeth and external cervical resorption.

Rosier P, Serati M, Solomon E, van Koeveringe G, Bachmann LM, Kessler TM. Randomised Controlled Trials Assessing the Clinical Value of Urodynamic Studies: A Systematic Review and Meta-analysis

Context

The role of urodynamic studies (UDSs) in the diagnosis of lower urinary tract symptoms (LUTS) is crucial. Although expert statements and guidelines underline their value for clinical decision-making in various clinical settings, the academic debate as to their impact on patient outcomes continues.

Objective

To summarise the evidence from all randomised controlled trials assessing the clinical usefulness of UDS in the management of LUTS.

Evidence acquisition

For this systematic review, searches were performed without language restrictions in three electronic databases until November 18, 2020. The inclusion criteria were randomised controlled study design and allocation to receive UDS or not prior to any clinical management. Quality assessment was performed by two reviewers independently, using the Cochrane Collaboration’s tool for assessing the risk of bias. A random-effect meta-analysis was performed on the uniformly reported outcome parameters.

Evidence synthesis

Eight trials were included, and all but two focused on women with pure or predominant stress urinary incontinence (SUI). A meta-analysis of six studies including 942 female patients was possible for treatment success, as defined by the authors (relative risk 1.00, 95% confidence interval: 0.93–1.07), indicating no difference in efficacy when managing women with UDS.

Conclusions

Although UDSs are not replaceable in diagnostics, since there is no other equivalent method to find out exactly what the lower urinary tract problem is, there are little data supporting its impact on outcomes. Randomised controlled trials have focussed on a small group of women with uncomplicated SUI and showed no added value, but these findings cannot be extrapolated to the overall patient population with LUTS, warranting further well-designed trials.

Patient summary

Despite urodynamics being the gold standard to assess lower urinary tract symptoms (LUTS), as it is the only method that can specify lower urinary tract dysfunction, more studies assessing the clinical usefulness of urodynamic studies (UDSs) in the management of LUTS are needed. UDS investigation is not increasing the probability of success in the treatment of stress urinary incontinence.

The impact of endoscopic ultrasound on the management and outcome of patients with oesophageal cancer: an update of a systematic review

AIM

To provide an updated systematic review concerning the impact of endoscopic ultrasound (EUS) in the modern era of oesophageal cancer staging.

MATERIALS AND METHODS

To update the previous systematic review, databases including MEDLINE and EMBASE were searched and studies published from 2005 onwards were selected. Studies reporting primary data in patients with oesophageal or gastro-oesophageal junction cancer who underwent radiological staging and treatment, regardless of intent, were included. The primary outcome was the reported change in management after EUS. Secondary outcomes were recurrence rate and overall survival. Two reviewers extracted data from included articles. This study was registered with PROSPERO (CRD42021231852).

RESULTS

Eighteen studies with 11,836 patients were included comprising 2,805 patients (23.7%) who underwent EUS compared to 9,031 (76.3%) without EUS examination. Reported change of management varied widely from 0% to 56%. When used, EUS fine-needle aspiration precluded curative treatment in 37.5%-71.4%. Overall survival improvements ranged between 121 and 639 days following EUS intervention compared to patients without EUS. Smaller effect sizes were observed in a randomised controlled trial, compared to larger differences reported in observational studies.

CONCLUSION

Current evidence for the effectiveness of EUS in oesophageal cancer pathways is conflicting and of limited quality. In particular, the extent to which EUS adds value to contemporary cross-sectional imaging techniques is unclear and requires formal re-evaluation.

Impact on patient management of non-mydriatic fundus photography compared to direct ophthalmoscopy in a regional Australian emergency department

OBJECTIVE

To investigate the management impact of non-mydriatic fundus photography (NMFP) implementation for appropriate ED patients; compare the diagnostic accuracy of direct ophthalmoscopy (DO) and NMFP, and determine the prevalence of fundus pathology in a regional Australian ED.

METHODS

This before/after crossover study prospectively enrolled patients presenting with headache, neurological deficit, visual disturbance and/or hypertensive urgency. Patients received DO examination, then separate NMFP examination. Emergency clinicians (ECs) were surveyed on their patient management plans following both DO examination and NMFP imaging. Telemedicine review of NMFP images was performed by an ophthalmologist within 48 h, and any additional management changes were documented.

RESULTS

The use of NMFP influenced changes in management in 52 (39%) of 133 enrolled patients (95% confidence interval 31-48%). Of these, 65% were escalations of management due to acute fundus pathology, while 35% were de-escalating changes following normal fundus findings. ECs diagnostic accuracy for acute fundus pathology improved from 0% to 29% sensitivity, and 59% to 84% specificity using DO and NMFP respectively, and telemedicine registrar review increased this to 50% sensitivity and 86% specificity. The period prevalence of acute fundus pathology was 10.5% (95% confidence interval 6-17%).

CONCLUSION

The addition of NMFP images can significantly impact the management of ED patients requiring fundus examination, facilitating expedited and optimised patient care. NMFP improves ECs diagnostic acumen for fundus pathology over DO examination and telehealth specialist review is important for diagnostic accuracy. There is a clinically important prevalence of fundus pathology in this regional ED setting.

Through the quality kaleidoscope: reflections on research in dentomaxillofacial imaging

The REduce research Waste And Reward Diligence statement has highlighted how weaknesses in health research can produce misleading results and waste valuable resources. Research on diagnostic efficacy in the field of dentomaxillofacial radiology (DMFR) is no exception to these criticisms and could be strengthened by more robust study designs, consistent use of a core set of outcome measures and completeness in reporting. Furthermore, we advocate that everyone participating in collaborative research on clinical interventions subscribes to the importance of methodological quality in how imaging methods are used. The aim of this paper, therefore, is to present a guide to conducting high-quality research on diagnostic efficacy in DMFR.We initially propose a framework inspired by the hierarchical model of efficacy of Fryback and Thornbury, highlighting study designs, measures of analysis, completeness of reporting and established guidelines to assist in these aspects of research. Bias in research, and measures to prevent or limit it, are then described.It is desirable to climb the Fryback and Thornbury "ladder" from technical efficacy, via accuracy and clinical efficacy, to societal efficacy of imaging methods. Efficacy studies on the higher steps of the ladder may be difficult to perform, but we must strive to answer questions of how useful our methods are in patient management and assess benefits, risks, costs, ethical and social issues. With the framework of six efficacy levels as the structure and based on our experience, we present information that may facilitate quality enhancement of diagnostic efficacy research in DMFR.

Radiomics and Deep Learning from Research to Clinical Workflow: Neuro-Oncologic Imaging

Imaging plays a key role in the management of brain tumors, including the diagnosis, prognosis, and treatment response assessment. Radiomics and deep learning approaches, along with various advanced physiologic imaging parameters, hold great potential for aiding radiological assessments in neuro-oncology. The ongoing development of new technology needs to be validated in clinical trials and incorporated into the clinical workflow. However, none of the potential neuro-oncological applications for radiomics and deep learning has yet been realized in clinical practice. In this review, we summarize the current applications of radiomics and deep learning in neuro-oncology and discuss challenges in relation to evidence-based medicine and reporting guidelines, as well as potential applications in clinical workflows and routine clinical practice.

The impact of computed radiography and teleradiology on patients' diagnosis and treatment in Mweso, the Democratic Republic of Congo

INTRODUCTION

High quality diagnostic imaging can provide increased diagnostic accuracy and help guide medical decision-making and management, however challenges for radiology in resource-limited settings are numerous. Diagnostic imaging and teleradiology have financial and logistical implications, so evidence of impact is crucial. We sought to test the hypothesis that the implementation of computed radiography with teleradiology consultation support will significantly change diagnoses and treatment plans in a resource limited setting.

METHOD

Paired before-after study to determine the therapeutic impact of an add-on diagnostic test. 'Preliminary Plan' and 'Final Plan' forms allowed direct comparison of diagnosis and treatment plans at initial consultation and following radiography and teleradiology. Consecutive consenting patients were included until the sample size (600) was reached. Changes in both diagnosis and treatment plan were analysed in the whole cohort, with sub-analyses of children aged <5 years, and cases of chest radiography.

RESULTS

Final analysis included 536 cases. Diagnosis changed following radiography and teleradiology in 62% of cases, and treatment plans changed in 61%. In chest radiography cases, 70% of diagnoses and 62% of treatment plans changed, while in children <5 years 66% of diagnoses and 58% of treatment plans changed. Reduced final treatment plans were most common for exploratory surgery (72% decrease), surgical orthopaedic intervention (62% decrease), and TB treatment (52% decrease), allowing more conservative medical or surgical management in 61 cases. Increased final treatment plans were highest in the orthopaedic and interventional surgery and referral categories. Of 42 cases requiring interventional surgery in the final plan, 26 (62%) were identified only after radiography and teleradiology. 16 additional cases were indicated for orthopaedic surgery, 10 cases required patient transfer, and TB treatment was indicated in 45 cases. A change in the original prescription plan occurred in 41% of 536 cases, with one or more prescriptions stopped in 28% of all cases.

CONCLUSION

We found that computed radiography with teleradiology had significant clinical value in this resource-limited setting, with the potential to affect both patient outcomes and treatment costs through providing improved diagnostics and avoiding unnecessary treatments and medications.

Impact of the radiographic method on treatment decisions related to dental caries in primary molars: a before-after study

OBJECTIVES

To evaluate the impact of radiographic examination on changes of treatment decision related to dental caries compared to decisions guided by visual inspection alone in primary molars.

MATERIALS AND METHODS

A total of 126 children aged 3-6 years who had sought dental assistance were randomly selected and examined by two calibrated examiners using visual inspection. A treatment plan regarding dental caries was generated based on this assessment. The same examiners then evaluated two bitewing radiographs, creating an additional treatment plan guided by concurrent assessment of both visual and radiographic methods. Occlusal and proximal surfaces of primary molars received a treatment decision as follows: (i) no treatment, (ii) non-operative treatment, and (iii) operative treatment. The frequency of changes in the treatment decision after radiographic examination was calculated, with subsequent Poisson multilevel regression analysis to evaluate variables influencing such changes.

RESULTS

Changes from "no treatment" decided with visual inspection to "non-operative treatment" after radiographic evaluation occurred in 52 surfaces (3.2%), and changes to "operative treatment" were observed in 46 dental surfaces (2.8%). Furthermore, 50 surfaces (6.2%) had their treatment decision changed from non-operative to operative treatment after radiographic assessment. In addition, changes were significantly more frequent in children with higher caries experience, on proximal surfaces and in 1st primary molars.

CONCLUSIONS

The impact of radiographic examination on changes in the treatment decision of primary molars made with visual inspection is modest. Changes are more frequent in children with higher caries experience and in proximal surfaces.

CLINICAL RELEVANCE

The benefits of the radiographic method for detecting caries in children, as a protocol in the diagnostic process, seem to be overestimated; the impact of this method on changes in treatment decision made by visual examination alone is low. Radiographs could be, however, useful in particular conditions, such as in children with high caries experience.

Decision making about healthcare-related tests and diagnostic test strategies. Paper 2: a review of methodological and practical challenges

OBJECTIVES

In this first of a series of five articles, we provide an overview of how and why healthcare-related tests and diagnostic strategies are currently applied. We also describe how our findings can be integrated with existing frameworks for making decisions that guide the use of healthcare-related tests and diagnostic strategies.

STUDY DESIGN AND SETTING

We searched MEDLINE, references of identified articles, chapters in relevant textbooks, and identified articles citing classic literature on this topic.

RESULTS

We provide updated frameworks for the potential roles and applications of tests with suggested definitions and practical examples. We also discuss study designs that are commonly used to assess tests' performance and the effects of tests on people's health. These designs include diagnostic randomized controlled trials and retrospective validation. We describe the utility of these and other currently suggested designs, which questions they can answer and which ones they cannot. In addition, we summarize the challenges unique to decision-making resulting from the use of tests.

CONCLUSION

This overview highlights current challenges in the application of tests in decision-making in healthcare, provides clarifications, and informs the proposed solutions.

Computed tomography (CT) in the selection of treatment for root-filled maxillary molars with apical periodontitis

OBJECTIVES

The aims of this study were to evaluate whether the use of CT facilitates agreement among endodontists in selecting treatments for root-filled maxillary molars with apical periodontitis and to assess the efficacy of CT in choosing a treatment for such teeth.

METHODS

39 root-filled maxillary molars from 34 patients with suspected apical periodontitis were independently evaluated by 4 endodontists and 1 postgraduate student (decision-makers). Treatment decisions were made based on intra-oral radiographs and a fictive clinical history. After 1-3 months, the same decision-makers repeated the examination of the same teeth but with additional information from a CT examination. Agreement between decision-makers with or without the availability of the CT results was measured with Cohen's kappa coefficient. Differences in selected treatments with or without accessibility to the CT results were plotted for the same endodontists using descriptive statistics.

RESULTS

The agreement in assessments among endodontists was slight or fair before the CT results were available (range: 0.081-0.535). No increase was observed after reviewing the CT results (range: 0.116-0.379). After the use of CT, the treatment plan was changed 38-76% of the time by all decision-makers, and the changes affected 57.8% of the cases in the study.

CONCLUSIONS

The endodontists in this study exhibited a low degree of agreement when choosing a treatment for root-filled maxillary molars with apical periodontitis. A CT examination of the investigated teeth did not result in a significantly higher degree of agreement, and CT frequently contributed to a shift in the selected therapy.

Impact of Molecular Diagnostics for Tuberculosis on Patient-Important Outcomes: A Systematic Review of Study Methodologies

BACKGROUND

Several reviews on the accuracy of Tuberculosis (TB) Nucleic Acid Amplification Tests (NAATs) have been performed but the evidence on their impact on patient-important outcomes has not been systematically reviewed. Given the recent increase in research evaluating such outcomes and the growing list of TB NAATs that will reach the market over the coming years, there is a need to bring together the existing evidence on impact, rather than accuracy. We aimed to assess the approaches that have been employed to measure the impact of TB NAATs on patient-important outcomes in adults with possible pulmonary TB and/or drug-resistant TB.

METHODS

We first develop a conceptual framework to clarify through which mechanisms the improved technical performance of a novel TB test may lead to improved patient outcomes and outline which designs may be used to measure them. We then systematically review the literature on studies attempting to assess the impact of molecular TB diagnostics on such outcomes and provide a narrative synthesis of designs used, outcomes assessed and risk of bias across different study designs.

RESULTS

We found 25 eligible studies that assessed a wide range of outcomes and utilized a variety of experimental and observational study designs. Many potentially strong design options have never been used. We found that much of the available evidence on patient-important outcomes comes from a small number of settings with particular epidemiological and operational context and that confounding, time trends and incomplete outcome data receive insufficient attention.

CONCLUSIONS

A broader range of designs should be considered when designing studies to assess the impact of TB diagnostics on patient outcomes and more attention needs to be paid to the analysis as concerns about confounding and selection bias become relevant in addition to those on measurement that are of greatest concern in accuracy studies.

The effect of cone beam CT (CBCT) on therapeutic decision-making in endodontics

OBJECTIVES

The aim was to assess to what extent cone beam CT (CBCT) used in accordance with current European Commission guidelines in a normal clinical setting has an impact on therapeutic decisions in a population referred for endodontic problems.

METHODS

The study includes data of consecutively examined patients collected from October 2011 to December 2012. From 2 different endodontic specialist clinics, 57 patients were referred for a CBCT examination using criteria in accordance with current European guidelines. The CBCT examinations were performed using similar equipment and standardized among clinics. After a thorough clinical examination, but before CBCT, the examiner made a preliminary therapy plan which was recorded. After the CBCT examination, the same examiner made a new therapy plan. Therapy plans both before and after the CBCT examination were plotted for 53 patients and 81 teeth. As four patients had incomplete protocols, they were not included in the final analysis.

RESULTS

4% of the patients referred to endodontic clinics during the study period were examined with CBCT. The most frequent reason for referral to CBCT examination was to differentiate pathology from normal anatomy, this was the case in 24 patients (45% of the cases). The primary outcome was therapy plan changes that could be attributed to CBCT examination. There were changes in 28 patients (53%).

CONCLUSIONS

CBCT has a significant impact on therapeutic decision efficacy in endodontics when used in concordance with the current European Commission guidelines.

Changes in treatment plan for carpal tunnel syndrome based on electrodiagnostic test results

This study evaluated how often the treatment plan for carpal tunnel syndrome (CTS) changed based on electrodiagnostic test results. Secondly, we assessed factors associated with a change in the treatment plan for CTS. One-hundred-and-thirty English-speaking adult patients underwent electrodiagnostic testing in a prospective cohort study. Treatment plan was recorded before and after testing. Treatment plan changed in 25 patients (19%) based on electrodiagnostic test results. The plan for operative treatment before testing decreased significantly after testing (83% versus 72%). The best logistic regression model for no change in treatment plan included a prolonged or non-recordable median distal sensory latency (normal, prolonged, or non-recordable), and explained 24% of the variation. For surgeons that manage CTS on the basis of objective pathophysiology rather than symptoms, electrodiagnostic test results often lead to changes in recommended treatment.

Using patient management as a surrogate for patient health outcomes in diagnostic test evaluation

Background

Before a new test is introduced in clinical practice, evidence is needed to demonstrate that its use will lead to improvements in patient health outcomes. Studies reporting test accuracy may not be sufficient, and clinical trials of tests that measure patient health outcomes are rarely feasible. Therefore, the consequences of testing on patient management are often investigated as an intermediate step in the pathway. There is a lack of guidance on the interpretation of this evidence, and patient management studies often neglect a discussion of the limitations of measuring patient management as a surrogate for health outcomes.

Methods

We discuss the rationale for measuring patient management, describe the common study designs and provide guidance about how this evidence should be reported.

Results

Interpretation of patient management studies relies on the condition that patient management is a valid surrogate for downstream patient benefits. This condition presupposes two critical assumptions: the test improves diagnostic accuracy; and the measured changes in patient management improve patient health outcomes. The validity of this evidence depends on the certainty around these critical assumptions and the ability of the study design to minimise bias. Three common designs are test RCTs that measure patient management as a primary endpoint, diagnostic before-after studies that compare planned patient management before and after testing, and accuracy studies that are extended to report on the actual treatment or further tests received following a positive and negative test result.

Conclusions

Patient management can be measured as a surrogate outcome for test evaluation if its limitations are recognised. The potential consequences of a positive and negative test result on patient management should be pre-specified and the potential patient benefits of these management changes clearly stated. Randomised comparisons will provide higher quality evidence about differences in patient management using the new test than observational studies. Regardless of the study design used, the critical assumption that patient management is a valid surrogate for downstream patient benefits or harms must be discussed in these studies.

Linking the evidence: intermediate outcomes in medical test assessments

OBJECTIVES

The aim of this study is to review how health technology assessments (HTA) of medical tests incorporate intermediate outcomes in conclusions about the effectiveness of tests on improving health outcomes.

METHODS

Systematic review of English-language test assessments in the HTA database from January 2005 to February 2010, supplemented by a search of the Web sites of International Network of Agencies for Health Technology Assessment (INAHTA) members.

RESULTS

A total of 149 HTAs from eight countries were assessed. Half evaluated tests for screening or diagnosis, a third for disease classification (including staging, prognosis, monitoring), and a fifth for multiple purposes. In seventy-one HTAs (48 percent) only diagnostic accuracy was reported, while in seventeen (11 percent) evidence of health outcomes was reported in addition to accuracy. Intermediate outcomes, mainly the impact of test results on patient management, were considered in sixty-one HTAs (41 percent). Of these, forty-seven identified randomized trials or observational studies reporting intermediate outcomes. The validity of these intermediate outcomes as a surrogate for health outcomes was not consistently discussed; nor was the quality appraisal of this evidence. Clear conclusions about whether the test was effective were included in approximately 60 percent of HTAs.

CONCLUSIONS

Intermediate outcomes are frequently assessed in medical test HTAs, but interpretation of this evidence is inconsistently reported. We recommend that reviewers explain the rationale for using intermediate outcomes, identify the assumptions required to link intermediate outcomes and patient benefits and harms, and assess the quality of included studies.

WITHDRAWN: Chest radiograph in acute respiratory infections

BACKGROUND

Chest radiography is widely used during the management of acute lower respiratory infections, but the benefits are unknown.

OBJECTIVES

To assess the effects of chest radiography on clinical outcome in acute lower respiratory infections.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, Issue 1), MEDLINE (1950 to January 2007) and EMBASE (January 1976 to February 2007).

SELECTION CRITERIA

Randomised or quasi-randomised trials of chest radiography in acute respiratory infections.

DATA COLLECTION AND ANALYSIS

Both review authors independently applied the inclusion criteria, extracted data and assessed trial quality.

MAIN RESULTS

We identified two trials. One, of 522 outpatient children (and performed by the review authors), found that 46% of both radiography and control participants had recovered by seven days (relative risk (RR) 1.01, 95% confidence interval (CI) 0.79 to 1.31). Thirty-three per cent of radiography participants and 32% of control participants made a subsequent hospital visit within four weeks (RR 1.02, 95% CI 0.79 to 1.30) and 3% of both radiography and control participants were subsequently admitted to hospital within four weeks (RR 1.02, 95% CI 0.41 to 2.52). The other trial involving 1502 adults attending an emergency department found no significant difference in length of illness, the single outcome prespecified for this review (mean of 16.9 days in radiograph group versus 17.0 days in control group, P > 0.05).

AUTHORS' CONCLUSIONS

There is no evidence that chest radiography improves outcome in outpatients with acute lower respiratory infection. The findings do not exclude a potential effect of radiography, but the potential benefit needs to be balanced against the hazards and expense of chest radiography. The findings apply to outpatients only.

Using the Principles of Randomized Controlled Trial Design to Guide Test Evaluation

The decision to use a new test should be based on evidence that it will improve patient outcomes or produce other benefits without adversely affecting patients. In principle, long-term randomized controlled trials (RCTs) of test-plus-treatment strategies offer ideal evidence of the benefits of introducing a new test relative to current best practice. However, long-term RCTs may not always be necessary. The authors advocate using the hypothetical RCT as a conceptual framework to identify what types of comparative evidence are needed for test evaluation. Evaluation begins by stating the major claims for the new test and determining whether it will be used as a replacement, add-on, or triage test to achieve these claims. A flow diagram of this hypothetical RCT is constructed to show the essential design elements, including population, prior tests, new test and existing test strategies, and primary and secondary outcomes. Critical steps in the pathway between testing and patient outcomes, such as differences in test accuracy, changes in treatment, or avoidance of other tests, are displayed for each test strategy. All differences between the tests at these critical steps are identified and prioritized to determine the most important questions for evaluation. Long-term RCTs will not be necessary if it is valid to use other sources of evidence to address these questions. Validity will depend on issues such as the spectrum of patients identified by the old and new test strategies.

Use of brain imaging (computed tomography and magnetic resonance imaging) in first-episode psychosis: review and retrospective study

OBJECTIVE

To identify and review available evidence on the diagnostic yield of brain computed tomographies (CTs) and magnetic resonance images (MRIs) in first-episode psychosis, and examine yield in our own institution (Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, Quebec).

METHOD

Using MEDLINE (1966 to October 2007) and EMBASE (1980 to October 2007), we identified and analyzed studies that examined imaging yields in first-episode psychosis; yield being defined as the percentage of scans showing abnormalities that may result in psychosis. We also retrospectively analyzed diagnostic yields in 46 patients hospitalized in our institution between 2001 and 2006 for first-episode psychosis.

RESULTS

Five studies were deemed relevant. Including our own series, the sample comprised 384 CT and 184 MRI scans. Point estimate for diagnostic yield was 1.3% for CT and 1.1% for MRI scans. These yields likely overestimate clinical usefulness of findings. MRI scans also resulted in a sizeable number of fortuitous, clinically irrelevant findings.

CONCLUSIONS

In first-episode psychosis, routine CT or MRI scans are of little benefit and should be reserved for situations where history or examination suggests neurological causation, or possibly for people aged 50 years and older.

Quality assessment of diagnostic before-after studies: development of methodology in the context of a systematic review

Background

Quality assessment tools for primary studies of test accuracy are relatively well developed, although only one is validated (QUADAS), but very little work has been done to develop tools to quality-assess studies evaluating the impact of diagnostic testing on management of patients (diagnostic or therapeutic yield). The recent draft NICE Guide to the Methods of Technology Appraisal (2007) suggests QUADAS "as a useful starting point for appraising studies that evaluate the sensitivity and specificity of a test" but does not mention how to quality assess diagnostic or therapeutic yield studies, in particular diagnostic before-after studies. In the context of undertaking a rapid systematic review of structural neuroimaging in psychosis for NICE, we describe the modifications that we made to QUADAS, our experience of this in practice and in relation to published theory on diagnostic or therapeutic yield studies.

Methods

The QUADAS tool was assessed for use in the review by two systematic reviewers with in-depth knowledge of the clinical area being reviewed and the types of studies being found in the searches that could answer the clinical question. Modifications were made following discussion as considered appropriate.

Results

Two QUADAS questions were removed altogether and. four additional questions were developed to capture additional quality issues not addressed by QUADAS. However, the developed checklist only partially helped to discern implications of the study designs on the results given.

Conclusion

The division between topic-specific and more generic quality items of relevance to diagnostic before-after studies is important. With more time, further work could have been done to create a better quality assessment tool, for example by incorporating some of the issues mentioned in previous work in this area. This paper is a discussion around quality assessment and is intended to offer insights into the types of issues that should be assessed. A quality assessment tool for diagnostic before-after studies that incorporates items from QUADAS and published theory needs to be further developed and validated.

Systematic review of the impact of endoscopic ultrasound on the management of patients with esophageal cancer

OBJECTIVES

Although endoscopic ultrasound (EUS) staging of esophageal cancer is established in clinical practice, high-quality evidence about its impact on patient outcomes is not available. This study aims to determine the impact of EUS for esophageal cancer staging on patient management and survival.

METHODS

A systematic review was conducted using Medline, PreMedline, Embase, and The Cochrane Library. Included studies were (i) comparative studies reporting survival following EUS esophageal cancer staging, (ii) therapeutic impact studies reporting change in patient management following EUS. The quality of included studies was critically appraised.

RESULTS

One systematic review, five studies reporting therapeutic impact, and two studies reporting patient survival were identified. The design and quality of the therapeutic impact studies varied widely. Management changed in 24-29 percent of patients following EUS staging of esophageal cancer (two studies). No studies provided data on the avoidance of surgery for this indication. One retrospective cohort study with historical control found EUS staging of esophageal cancer improved patient survival; a second study with similar design limitations did not find a survival benefit for EUS staging in patients undergoing resection. These studies had a high potential for bias, limiting the value of these findings.

CONCLUSIONS

Two studies provided evidence of a change in patient management following EUS for staging esophageal cancer, a higher level of evidence for a clinical benefit than can be obtained from accuracy studies alone. This evidence contributed to a recommendation for public funding of EUS in staging esophageal cancer in Australia.

Chest radiograph in acute respiratory infections

BACKGROUND

Chest radiography is widely used during the management of acute lower respiratory infections, but the benefits are unknown.

OBJECTIVES

To assess the effects of chest radiography on clinical outcome in acute lower respiratory infections.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, Issue 1), MEDLINE (1950 to January 2007) and EMBASE (January 1976 to February 2007).

SELECTION CRITERIA

Randomised or quasi-randomised trials of chest radiography in acute respiratory infections.

DATA COLLECTION AND ANALYSIS

Both review authors independently applied the inclusion criteria, extracted data and assessed trial quality.

MAIN RESULTS

We identified two trials. One, of 522 outpatient children (and performed by the review authors), found that 46% of both radiography and control participants had recovered by seven days (relative risk (RR) 1.01, 95% confidence interval (CI) 0.79 to 1.31). Thirty-three per cent of radiography participants and 32% of control participants made a subsequent hospital visit within four weeks (RR 1.02, 95% CI 0.79 to 1.30) and 3% of both radiography and control participants were subsequently admitted to hospital within four weeks (RR 1.02, 95% CI 0.41 to 2.52). The other trial involving 1502 adults attending an emergency department found no significant difference in length of illness, the single outcome prespecified for this review (mean of 16.9 days in radiograph group versus 17.0 days in control group, P > 0.05).

AUTHORS' CONCLUSIONS

There is no evidence that chest radiography improves outcome in outpatients with acute lower respiratory infection. The findings do not exclude a potential effect of radiography, but the potential benefit needs to be balanced against the hazards and expense of chest radiography. The findings apply to outpatients only.

The value of thoracic computed tomography scans in clinical diagnosis: a prospective study

BACKGROUND

Computed tomography (CT) scans are used extensively to investigate chest disease because of their cross-sectional perspective and superior contrast resolution compared with chest radiographs. These advantages lead to a more accurate imaging assessment of thoracic disease. The actual use and evaluation of the clinical impact of thoracic CT has not been assessed since scanners became widely available.

OBJECTIVE

To identify patterns of utilization, waiting times and the impact of CT scan results on clinical diagnoses.

DESIGN

A before and after survey of physicians who had ordered thoracic CT scans.

SETTING

Vancouver General Hospital--a tertiary care teaching centre in Vancouver, British Columbia.

SUBJECTS

Physicians who had ordered CT scans.

INTERVENTION

Physicians completed a standard questionnaire before and after the CT scan result was available.

MEASUREMENTS

Changes in the clinical diagnosis, estimates of the probabilities for the diagnosis both before and after the CT scan, and waiting times.

RESULTS

Four hundred fifty-four thoracic CT cases had completed questionnaires, of whom 80% were outpatients. A change in diagnosis was made in 48% of cases (25% with a normal CT scan and 23% with CT scan findings that indicated a different diagnosis). The largest change in probability scores for the clinical diagnosis before and after the CT scan was 43.9% for normal scans, while it was 36.3% for a different diagnosis and 26.3% for the same diagnosis. High-priority scans were associated with decreased waiting time (--7.89 days for each unit increase in priority).

CONCLUSIONS

The CT scan results were associated with a change in diagnosis in 48% of cases. Normal scans constituted 25% of the total and had the greatest impact scores. Waiting times were highly correlated with increased urgency of the presenting problem.

Peripheral arterial disease: therapeutic confidence of CT versus digital subtraction angiography and effects on additional imaging recommendations

PURPOSE

To compare multi-detector row computed tomographic (CT) angiography and digital subtraction angiography (DSA) prior to revascularization in patients with symptomatic peripheral arterial disease for the purpose of assessing recommendations for additional imaging and physician confidence ratings for chosen therapy.

MATERIALS AND METHODS

In a randomized controlled trial, 73 patients were assigned to CT angiography, and 72 were assigned to DSA. Physician confidence in the treatment decision was measured as a continuous outcome on a scale of 0-10 (uncertain to certain) and as a dichotomous outcome (further imaging recommended, yes or no). Mean confidence scores and additional imaging recommendations were compared between CT and DSA groups in an intention-to-diagnose-and-treat analysis. To detect trends in confidence, confidence scores were plotted over time, and multiple linear regression analysis was performed. To detect trends in additional imaging recommendations, logistic regression analysis was used. Data from eligible nonrandomized patients were analyzed separately.

RESULTS

No statistically significant difference in baseline characteristics between randomized groups was found. CT had a lower confidence score than did DSA (7.2 vs 8.2, P < .001). Further imaging was recommended more often after CT (25 of 71 patients, 35%) than after DSA (nine of 66 patients, 14%; P = .003). Analysis of trends demonstrated increasing (but not statistically significant) confidence in CT and stable confidence in DSA. No significant difference was found in baseline characteristics between randomized and nonrandomized patients. Among nonrandomized patients, no significant difference in mean confidence score (8.2 vs 8.3, P = .26) was found between CT (n = 24) and DSA (n = 26).

CONCLUSION

With CT angiography, physician confidence decreases with an associated increase in additional imaging prior to revascularization in patients with symptomatic peripheral arterial disease. Given that CT is less invasive than DSA, results suggest that CT may replace DSA in selected cases.

Prospective use of serial questionnaires to evaluate the therapeutic efficacy of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in suspected lung cancer

BACKGROUND

A study was undertaken to study the effect of (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) on the diagnosis and management of clinically problematic patients with suspected non-small cell lung cancer (NSCLC).

METHODS

A prospective before-after study was performed in a cohort of all 164 patients (university/community settings) referred for PET between August 1997 and July 1999. PET was restricted to cases where non-invasive tests had failed to solve clinical problems. The impact on diagnostic understanding and management was assessed using questionnaires (intended treatment without PET, actual treatment choice after PET, post hoc clinical assessment).

RESULTS

Diagnostic problems especially pertained to unclear radiological findings (n=112; 63%), mediastinal staging (n=36; 20%), and distant staging issues (n=16; 9%). PET findings were validated by reviewing medical records. PET had a positive influence on diagnostic understanding in 84%. Improved diagnostic understanding solely based on PET was reported in 26%. According to referring physicians, PET resulted in beneficial change of treatment in 50%. Cancelled surgery was the most frequent change in treatment after PET (35%).

CONCLUSION

FDG PET applied as "add on" technology in patients with these clinical problems appears to be a clinically useful tool, directly improving treatment choice in 25% of patients. The value of increased confidence induced by PET scanning requires further evaluation.

Reproducibility and clinical value of 18F-fluorodeoxyglucose positron emission tomography in recurrent melanoma

The purpose of this study was to assess the reproducibility and clinical impact of positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) in patients with (suspected) recurrent melanoma. The clinical value of PET was prospectively measured in 58 consecutive patients referred for PET because of unresolved clinical questions after conventional work-up. Diagnostic understanding and therapy choice by referring physicians were evaluated before, directly after, and 6 months after PET. Observer agreement of PET readings was measured with respect to various parameters (interpretation, number and localization of lesions, 'clinically decisive' metastases), using intra-class correlation coefficients. FDG PET improved diagnostic understanding in 33 cases (57%). In six patients (10%), diagnostic understanding was solely based on PET information. According to the attending clinicians, PET contributed to a positive change of planned treatment in 23 patients (40%) and increased confidence in the chosen treatment in 23 (40%). Observer agreement of PET readings was very high (intra-class correlation coefficients were between 0.87 and 0.94). The diagnostic value related especially to the whole-body scan technique and the superior specificity, compared to conventional work-up. It is concluded that, in problematical cases with (suspected) recurrent melanoma, 18F-FDG PET had considerable impact on diagnostic understanding and management. Together with the excellent observer reliability, these results justify further studies to determine the optimal place of PET in routine diagnostic algorithms in recurrent melanoma.

MR imaging of the wrist: effect on clinical diagnosis and patient care

PURPOSE

To evaluate the effect of magnetic resonance (MR) imaging of the wrist on clinicians' diagnoses, diagnostic certainty, and patient care.

MATERIALS AND METHODS

A controlled observational study was performed. Referring clinicians completed questionnaires about diagnosis and intended management before and after wrist MR imaging. One hundred eighteen consecutive patients referred for MR imaging of the wrist were recruited from the MR imaging units at a regional teaching hospital and a large district general hospital. The main measures were changes in the clinicians' leading and subsidiary diagnoses after MR imaging, their certainty in these diagnoses, and changes in intended patient care.

RESULTS

Questionnaires were incorrectly completed for five patients, questionnaires were not returned for three, appointments were canceled for 10, and two could not tolerate the MR examination. Complete follow-up data were available for 98 patients. The clinical diagnosis changed in 55 of 98 patients; in the remaining 43 patients, diagnostic certainty increased in 23. Clinicians reported that MR imaging had substantially improved their understanding of the disease in 67 of 98 patients. The care plan changed in 45 of 98 patients, with a shift away from surgical treatment. Twenty-eight patients were discharged without further investigation. MR imaging was similarly effective in the regional teaching center and the district general hospital.

CONCLUSION

MR imaging of the wrist influences clinicians' diagnoses and management plans.

Influence of imaging on clinical decision making in the treatment of lower back pain

PURPOSE

To assess the impact of cross-sectional imaging with magnetic resonance (MR) imaging or computed tomography (CT) on clinical decision making for patients with lower back pain (LBP).

MATERIALS AND METHODS

A randomized controlled before-and-after study was performed in 145 patients who had symptomatic lumbar spinal disorders and had been referred to orthopedists or neurosurgeons. Participants were a subgroup within a multicenter pragmatic randomized comparison of two imaging policies on LBP treatment: "imaging" versus "no imaging," unless a clear indication developed. Paired assessments were made of diagnosis, diagnostic confidence, proposed treatment, treatment confidence at trial entry and follow-up, and expectations of imaging. Data were analyzed according to the groups as randomized.

RESULTS

At follow-up, there were no statistically significant differences between the groups with respect to diagnosis or treatment plans. Significant increases in diagnostic and therapeutic confidence between trial entry and follow-up were observed for both groups, with a significantly greater increase in diagnostic confidence (P =.01) in the imaging group.

CONCLUSION

Imaging may increase diagnostic confidence but has minimal influence on diagnostic or therapeutic decisions for patients with LBP. The results highlight the need for evidence-based guidelines for imaging in LBP treatment.

Studies of symptoms in primary care

Publications on the frequency of defined symptoms in the practice setting, underlying conditions and prognosis have been rare in the past. Also, studies addressing these questions have suffered from several methodological problems. We therefore developed criteria to help investigators improve the quality of study design, implementation and publication. Studies evaluating symptoms in practice can make an important contribution to a more rational approach to diagnostic decision making especially in primary care.

What is the real clinical utility of echocardiography? A prospective observational study

This was a prospective, structured interview to evaluate physician expectations of echocardiography and the subsequent impact on patient care. The setting involved requests for echocardiograms in patients admitted to a tertiary care teaching hospital. Measurements included assessment of the diagnostic and therapeutic implications of echocardiography perceived by the physicians and subsequently reported and confirmed by blinded chart review. From January to May 1997, 542 echocardiograms were performed on 500 inpatients (age 62 +/- 17 years; 56% men). Referring physicians were mainly house staff (83%) and from medical services. The main indications were evaluation of left ventricular function (54%) or valve function (16%). At the time of the request, 89% of physicians believed that echocardiography was needed to guide future investigations or treatment, although in 24% of cases, physicians could not provide details of such. A reported change in treatment occurred in 57% and was validated by chart review in 38%. Changes occurred more frequently in patients in the intensive care unit versus those not in the intensive care unit (54% vs 37%, P =.02) but were similar between attending physicians and house staff (frequency of change 41% vs 39%, P = not significant) and between those with and those without previous echocardiograms (38% vs 39%, P = not significant). The utility of the echocardiogram to influence treatment decisions in hospitalized patients is high, especially in critically ill patients. However, this impact is less than is anticipated at the time of the initial request. Further studies involving more select populations of patients are required.

The clinical utility of invasive diagnostic techniques in the setting of ventilator-associated pneumonia. Canadian Critical Care Trials Group

OBJECTIVE

To evaluate the clinical utility of bronchoscopy with protected brush catheter (PBC) and BAL for patients with ventilator-associated pneumonia (VAP).

DESIGN

Prospective cohort study.

SETTING

Ten tertiary care ICUs in Canada.

PATIENTS

Ninety-two mechanically ventilated patients with a clinical suspicion of VAP who underwent bronchoscopy were compared with 49 patients with a clinical suspicion of pneumonia who did not.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

We compared antibiotic use, duration of mechanical ventilation, ICU stay, and mortality. In addition, for patients who received bronchoscopy, we administered a questionnaire (before and after bronchoscopy) to evaluate the effect of PBC or BAL on (1) physician perception of the probability of VAP, (2) physician confidence in the diagnosis of VAP, and (3) changes to antibiotic management. After bronchoscopy results became available, from the physician's perspective, the diagnosis of VAP was deemed much less likely (p < 0.001), confidence in the diagnosis increased (p = 0.03), and level of comfort with the management plan increased (p = 0.02). Following the results of invasive diagnostic tests, in the group that underwent bronchoscopy, patients were receiving fewer antibiotics (31/92 vs 9/49, p = 0.05) and more patients had treatment with all their antibiotics discontinued (18/92 vs 3/49, p = 0.04) compared with the group that did not undergo bronchoscopy. Duration of mechanical ventilation and ICU stay were similar between the two groups, but mortality was lower in the group that underwent bronchoscopy with PBC or BAL (18.5% vs 34.7%, p = 0.03).

CONCLUSIONS

Invasive diagnostic testing may increase physician confidence in the diagnosis and management of VAP and allows for greater ability to limit or discontinue antibiotic treatment. Whether performing PBC or BAL affects clinically important outcomes requires further study.

A critical synopsis of the diagnostic and screening radiology outcomes literature

In summary, the radiology outcomes research literature is both extensive and broad. The methodologic quality, however, is quite variable. Overall, this quality could be improved by intervention in two areas: methodologic dissemination and development. The number of researchers investigating radiology-related outcomes is high, and presently there are over 20 journals devoted exclusively to radiology research. Even with a relatively narrow definition of "outcomes," we identified over 200 radiology outcomes studies, most from the past few years. However, the methodologic quality of most of these articles was relatively low, with important design flaws and biases. Nonetheless, a substantial number of radiology publications do employ state-of-the-art research methods and innovative approaches to methodologic challenges. The quality of radiology outcomes research overall would benefit tremendously from dissemination of such research methods. Instruction in outcomes research methods is accessible to radiologists. For example, there have been several recent articles and series of articles on outcomes research methods in JAMA, including guidelines for the performance and reporting of cost-effectiveness analyses (38-40) and for developing clinical prediction rules (57). Within radiology, several recent articles have appeared on, among other things, cost-effectiveness analysis (34,59,60), assessing quality of life (43), screening for disease (53), and defining the study population (61). The research compendium compiled for the GERRAF (General Electric-Association of University Radiologists Radiology Research Academic Fellowships) program remains a comprehensive methodologic source for many of the issues in radiology outcomes research, and outcomes research methods courses are offered every year at the Society for Health Services Research in Radiology and Society for Medical Decision Making meetings, as well as at the meeting of the Radiological Society of North America. Even so, awareness of the need for such research techniques remains limited. Dissemination of sound research methods is limited at least in part by the current incentives in radiology research. At many institutions, the number of research publications produced, rather than their quality, determines promotion or academic success. Unfortunately, more rigorous study designs often require more time and resources. Further, because peer reviewers are often as uninformed about research methods as the bulk of those who are submitting manuscripts, it may actually be more difficult to publish articles with more advanced methodologic designs. The standard in radiology is the uncontrolled case series, and deviation from the standard may make acceptance for publication more difficult. On a more optimistic note, recent publication of a number of methodology articles suggests that at least some journals are promoting improved research in methodology (43,53,59-61). We hope that time will be available for manuscript reviewers to learn to understand the strengths and weaknesses of various research approaches. If more rigorous study designs were required for publication, radiology outcomes research would probably improve drastically. Nevertheless, the current peer-review system does not effectively promote sound research design. The other great incentive in research is funding. Clearly, if advanced research design is required for funding, then there is incentive for improvement in research quality. Traditionally, National Cancer Institute and other National Institutes of Health and public sector funding has been predicated on a high level of research sophistication. Undoubtedly, availability of grants for diagnostic and screening imaging clinical trials and other research will go far to improve radiology research methods. The other traditional source of research funding is industry.

Economic evaluation of diagnostic technology. Methodological challenges and viable solutions

The principles of economic evaluation are increasingly accepted by clinicians and policy makers as evidence from a significant number of studies becomes available to support their decisions. However, methods of assessment still need to be improved. This paper reports a comprehensive review of methodological challenges in the economic evaluation of diagnostic technology, where such challenges are more evident. This review formed the basis for a prioritized research agenda, with four main areas: modeling techniques for dealing with complexity; measures of the opportunity cost of shared resources; techniques for eliciting decision makers' utility functions for diagnostic tests; and ways of assessing the robustness of decisions. A number of methodological solutions are proposed, aimed at capturing elements and relationships that are usually neglected and fully recognizing the presence of an inductive cognitive component in decision-making processes.

Randomised controlled trial of clinical outcome after chest radiograph in ambulatory acute lower-respiratory infection in children

BACKGROUND

When available, chest radiographs are used widely in acute lower-respiratory-tract infections in children. Their impact on clinical outcome is unknown.

METHODS

522 children aged 2 to 59 months who met the WHO case definition for pneumonia were randomly allocated to have a chest radiograph or not. The main outcome was time to recovery, measured in a subset of 295 patients contactable by telephone. Subsidiary outcomes included diagnosis, management, and subsequent use of health facilities.

FINDINGS

There was a marginal improvement in time to recovery which was not clinically significant. The median time to recovery was 7 days in both groups (95% CI 6-8 days and 6-9 days in the radiograph and control groups respectively, p=0.50, log-rank test) and the hazard ratio for recovery was 1.08 (95% CI 0.85-1.34). This lack of effect was not modified by clinicians' experience and no subgroups were identified in which the chest radiograph had an effect. Pneumonia and upper-respiratory infections were diagnosed more often and bronchiolitis less often in the radiograph group. Antibiotic use was higher in the radiograph group (60.8% vs 52.2%, p=0.05). There was no difference in subsequent use of health facilities.

INTERPRETATION

Chest radiograph did not affect clinical outcome in outpatient children with acute lower-respiratory infection. This lack of effect is independent of clinicians' experience. There are no clinically identifiable subgroups of children within the WHO case definition of pneumonia who are likely to benefit from a chest radiograph. We conclude that routine use of chest radiography is not beneficial in ambulatory children aged over 2 months with acute lower-respiratory-tract infection.

Comparative assessment of digital and analog radiography: diagnostic accuracy, cost analysis and quality of care

OBJECTIVE

The aim of this study was to compare digital and conventional radiography for diagnostic accuracy, direct costs, and quality of care.

MATERIALS AND METHODS

Diagnostic accuracy was assessed by a critical review of the literature on sensitivity, specificity and ROC analysis of these imaging techniques and by a survey with a panel of radiologists. Direct costs and quality of care were evaluated with a before/after study of the implementation of digital radiography in a Department of Radiology in 'Hospices Civils de Lyon' (France). We included 292 patients and measured duration of examinations and direct costs of equipment, films, maintenance and depreciation. To evaluate any changes in working conditions and patient management, a questionnaire was filled out by the staff of the department.

RESULTS

Diagnostic accuracy with digital radiography was equivalent to that of conventional radiography but there were wide variations depending on the type of examination. In 1993, although digital radiography resulted in savings of FF 18,000 including tax (US$ 3600) on film consumption for 1 year of examinations, there was a global additional cost of FF 253,000 (US$ 50,600) for maintenance and depreciation. Results showed a nonsignificant tendency to reduced procedure times for all examinations. Working conditions improved, including greater availability for the patient, improved safety, and increased job interest.

CONCLUSION

Digital radiography can be introduced into a large hospital to improve patient and staff conditions, at a higher cost than analog radiography, and depending on the type of examinations performed by the radiology department.

Influence of magnetic resonance imaging on diagnosis and therapeutic intention

RATIONALE AND OBJECTIVES

We assessed the contribution of magnetic resonance (MR) imaging to diagnostic and therapeutic decision making.

METHODS

In a before-after observational study, we collected information from clinicians before and after patients were given MR examinations. We studied 406 cases selected from consecutive referrals to a single MR imaging facility in Manitoba between November 1, 1991, and October 30, 1992, for diagnosis of suspected brain, spinal column, or large-joint disorder. We examined changes in diagnoses, changes in clinician diagnostic confidence, and changes in therapeutic intentions after MR examinations.

RESULTS

Overall, MR imaging findings contributed to a change in referring physicians' diagnoses or diagnostic confidence in 76% of the cases. Referring physicians reported a change in provisional diagnosis in 42% of the cases. In 67% of these cases, the referring physician's provisional diagnosis was ruled out by normal examination findings; in the remaining 33% of the cases, an alternate diagnosis was offered by the consulting radiologist. In the 58% of the cases in which the provisional diagnosis was not altered by MR imaging findings, clinical confidence in the provisional diagnosis increased in 46% of the cases and decreased in 12% of the cases. Management plans were reported to be altered in 54% of the cases; in 24% of the cases, therapeutic intentions changed from lower to higher levels of intervention.

CONCLUSION

Although MR imaging had a substantial influence on clinicians' decisions concerning diagnoses, the influence of MR imaging findings on therapeutic decision making, and therefore on patients' health status, was more moderate.

Self-critical federal science? The ethics experiment within the U.S. Human Genome Project

On October 1, 1988, thirty-five years after co-discovering the structure of the DNA molecule, Dr. James Watson launched an unprecedented experiment in American science policy. In response to a reporter's question at a press conference, he unilaterally set aside 3 to 5 percent of the budget of the newly launched Human Genome Project to support studies of the ethical, legal, and social implications of new advances in human genetics. The Human Genome Project (HGP), by providing geneticists with the molecular maps of the human chromosomes that they use to identify specific human genes, will speed the proliferation of a class of DNA-based diagnostic and risk-assessment tests that already create professional ethical and health-policy challenges for clinicians. “The problems are with us now, independent of the genome program, but they will be associated with it,” Watson said. “We should devote real money to discussing these issues.” By 1994, the “ELSI program” (short for “Ethical, Legal, and Social Implications”) had spent almost $20 million in pursuit of its mission, and gained both praise and criticism for its accomplishments.

Staging for M disease

The presence of distant metastatic disease (M disease) in non-small-cell cancer patients is associated with a poor prognosis, and surgical resection at the primary site is contraindicated. Careful preoperative evaluation to identify the subset of patients presenting with M disease is essential in order to avoid unnecessary surgery. Current indications for the use of diagnostic techniques and the methods utilized to detect metastatic disease at the commonest sites encountered in patients with non-small-cell carcinoma, including the pleura, central nervous system, liver, adrenal glands, and skeletal system, are discussed.

The clinical utility of transcranial Doppler ultrasound in suspected vertebrobasilar ischemia

The impact of transcranial Doppler ultrasound (TCD) on the management of 107 consecutively referred patients with suspected vertebrobasilar ischemia was studied. Physicians who referred patients for TCD of the posterior circulation were interviewed before and after being given the results of the TCD examination. Management plans devised prior to knowledge of the TCD results were compared to those devised after TCD results were given. Management changed in 42% of the patients after TCD results were given, and there was a 58% reduction in the use of angiography (p = 0.04) and a 128% increase in the use of aspirin (p = 0.005). Changes in the use of anticoagulants and other diagnostic or therapeutic approaches were not significant. TCD appears to have a significant impact on the management of patients with suspected vertebrobasilar ischemia.