Difference In Diagnostic Accuracy Research Articles

Education in Clinical Reasoning: An Experimental Study on Strategies to Foster Novice Medical Students’ Engagement in Learning Activities

PurposeClinical reasoning forms the interface between medical knowledge and medical practice. However, it is not clear how to organize education to foster the development of clinical reasoning. This study compared two strategies to teach clinical reasoning. MethodAs part of a regular clinical reasoning course 333 students participated in a two-phase experiment. In the learning phase, participants were randomly assigned to either the conventional strategy (CS) or the new strategy (NS). Participants in the CS solved a clinical case using a written description of a patient encounter and individual study. Participants assigned to the NS solved the same case using a video patient encounter and group discussion. One week later, all participants took the same diagnostic performance test. Performance on the diagnostic test and differences between the groups regarding their interest, cognitive engagement, appreciation of the educational activity, and time investment in self-study were analyzed. ResultsThere was no significant effect of teaching strategy on diagnostic performance (p=.23). Students in the NS condition showed more interest during the session (p=.003) and were more appreciative of the course when assigning an overall grade than the students in the CS condition (p<.001). The NS students reported having spent fewer hours studying the clinical case individually before the group session than the CS students (p<.001). DiscussionThe NS resulted in more students’ involvement and higher appreciation of the learning activity compared to the CS. There was no difference in diagnostic accuracy, but the NS seems more efficient: to achieve the same performance, the NS students needed only half the preparation time before the learning session than the students working under the CS. This higher efficiency may be due to the benefits of small-group learning, but clarifying this finding requires further investigation.

Comparison of diagnostic utility of semi-quantitative analysis for DAT-SPECT for distinguishing DLB from AD

PurposeIt is widely known that there is low striatal 123I-FP-CIT dopamine transporter single photon emission computed tomography (DAT-SPECT) uptake in patients with dementia with Lewy bodies (DLB). However, a consistent quantitative evaluation method for DAT-SPECT has not yet been established. There are two semi-quantitative software packages for DAT-SPECT available in Japan, namely, DaTView and DaTQUANT. The aim of this study was to identify which of these is superior for distinguishing DLB from AD. Moreover, we aimed to identify which region of the striatum is more suitable for distinguishing DLB from AD. MethodsPatients with Alzheimer's disease (AD) (n=95) and patients with DLB (n=133) who underwent DAT-SPECT were enrolled. DaTView and DaTQUANT were used as semi-quantitative analysis tools for DAT-SPECT. ResultsThere were significant correlations in DAT uptake between DaTView and entire regions by DaTQUANT. There was no significant difference in diagnostic accuracy between DaTView and DaTQUANT except in the posterior putamen by DaTQUANT. ConclusionsFor distinguishing DLB from AD, both of DaTView and DaTQUANT software are useful. Moreover, assessing the DAT uptake in entire striatum by DaTView might be sufficient for distinguishing DLB from AD.

Comparison of the accuracy of US-guided biopsy of breast masses performed with 14-gauge, 16-gauge and 18-gauge automated cutting needle biopsy devices, and review of the literature.

To compare the diagnostic accuracy of ultrasound (US)-guided core needle biopsy (CNB) of breast masses performed with 14-gauge, 16-gauge and 18-gauge needles. We retrospectively reviewed the charts of 1,112 patients who underwent US-guided breast CNB with 14-gauge, 16-gauge and 18-gauge needles. Cases with surgical excision or a minimum of 2years of imaging follow-up were included. Rates of sample inadequacy, discordance with surgical or imaging findings and upgrade of DCIS to invasive cancer or high-risk lesion to in situ or invasive cancer were computed for each needle size. The study included 703 CNBs: 203 performed with 14-gauge, 235 with 16-gauge and 265 with 18-gauge needles. There were no significant differences between 14-gauge, 16-gauge and 18-gauge needles in rates of specimen inadequacy (0%, 0.4% and 1.9%, respectively) (p = 0.084); surgical discordance (2.6%, 2.9% and 3.8%) (p = 0.76); imaging discordance (0%, 0% and 2%) (p = 1.0); DCIS upgrade (43%, 43% and 36%) (p = 1.00) or high-risk lesion upgrade (38%, 25% and 55%) (p = 0.49). There was no statistically significant difference in diagnostic accuracy of US-guided CNB of breast masses performed with 14-gauge, 16-gauge and 18-gauge needles. • Percutaneous image-guided breast core needle biopsy (CNB) is the standard of care. • Breast CNB with 14-gauge, 16-gauge and 18-gauge needles has similar diagnostic accuracy. • Smaller gauge needles can be confidently used for ultrasound-guided breast CNB.

Comparing the diagnostic accuracy of ultrasound in the community and in the hospital setting for urinary calculi: A retrospective cohort study

Objective: The objective of this article is to test whether there is a significant difference in diagnostic accuracy between hospital and community-based ultrasound (US) for the detection of urinary calculi in the United Kingdom (UK). Materials and methods: A 30-month, single-blind, retrospective cohort study of all patients referred to Kent and Canterbury Hospital urology multidisciplinary meeting for suspected urinary calculi was conducted. Only those investigated with US and non-contrast computed tomography (NCCT, the gold standard) for their calculi were included. Concordance of US and NCCT was stratified by US location: i.e. either the hospital or community setting (e.g. the latter via general practitioners (GPs) or independent radiographers). Fisher’s exact test was subsequently utilised to test for any significant difference between these two patient groups. Results: Of 2464 patients referred, 257 had both ultrasound and NCCT in their diagnostic workup. Of these, 150 and 107 patients had their US performed in hospital and community settings, respectively. No significant difference in the accuracy of US was detected between the two groups for the detection of urinary calculi when compared with NCCT. Conclusion: US carried out by independent radiographers and GPs in the community is just as accurate as US carried out by hospital sonographers for the detection of urinary calculi in the UK. Greater use of community US for the diagnosis of urinary calculi may promote greater patient/GP satisfaction and reduce hospital attendance without loss of diagnostic accuracy.

The impact of a focused vascular lower limb arterial duplex (F-VLAD) scan in management decisions for acute limb ischaemia.

To establish the diagnostic accuracy of a 'focused vascular lower limb arterial duplex scan (F-VLAD)' developed to facilitate rapid decision-making for acute limb ischaemia (ALI). Ten cases of ALI were identified from our patient database; clinical details, history and examination findings were extracted from the clinical notes. Original 'full' duplex ultrasound (DUS) pictorial reports were 're-formatted' to include only anatomical segments included in the 'F-VLAD' scan. The series of 10 reports were emailed to 1741 vascular surgeons. Each recipient received a random mixture of full and F-VLAD scans. Participants were asked regarding next step in management and confidence in decision-making (Likert scale; 1 strongly disagree, 5 strongly agree). The cases were again sent out to the same database and respondents were asked as to the cause of ischaemia (embolic or thrombosis). Eighty-one participants responded to the first survey and 43 participants to the second survey. Participants felt more confident making decisions regarding management using the full duplex report compared to the F-VLAD report (4 (3-4) vs 3 (2-4), median (IQR); p<0.001). However, there was no significant difference in diagnostic accuracy (differentiating embolus from thrombosis) when comparing the F-VLAD and full DUS reports (85.4% vs 88.3%; p=0.461). F-VLAD and 'full' DUS reports had comparable sensitivity (85.1% vs 86.8%), specificity (85.6% vs 89.2%),positive predictive value (PPV) (80.4% vs 81.9%) and negative predictive value (NPV) (89.2% vs 92.2%), respectively. The F-VLAD scan has comparable accuracy to a traditional full DUS in diagnosing the underlying aetiology of ALI. This may facilitate surgeon-performed point-of-care DUS.

Endoleak detection using single-acquisition split-bolus dual-energy computer tomography (DECT)

ObjectivesTo assess a single-phase, dual-energy computed tomography (DECT) with a split-bolus technique and reconstruction of virtual non-enhanced images for the detection of endoleaks after endovascular aneurysm repair (EVAR).MethodsFifty patients referred for routine follow-up post-EVAR CT and a history of at least one post-EVAR follow-up CT examination using our standard biphasic (arterial and venous phase) routine protocol (which was used as the reference standard) were included in this prospective trial. An in-patient comparison and an analysis of the split-bolus protocol and the previously used double-phase protocol were performed with regard to differences in diagnostic accuracy, radiation dose, and image quality.ResultsThe analysis showed a significant reduction of radiation dose of up to 42 %, using the single-acquisition split-bolus protocol, while maintaining a comparable diagnostic accuracy (primary endoleak detection rate of 96 %). Image quality between the two protocols was comparable and only slightly inferior for the split-bolus scan (2.5 vs. 2.4).ConclusionsUsing the single-acquisition, split-bolus approach allows for a significant dose reduction while maintaining high image quality, resulting in effective endoleak identification.Key Points• A single-acquisition, split-bolus approach allows for a significant dose reduction.• Endoleak development is the most common complication after endovascular aortic repair (EVAR).• CT angiography is the imaging modality of choice for aortic aneurysm evaluation.

M-Health for Improving Screening Accuracy of Acute Malnutrition in a Community-Based Management of Acute Malnutrition Program in Mumbai Informal Settlements.

Acute malnutrition is linked to child mortality and morbidity. Community-Based Management of Acute Malnutrition (CMAM) programs can be instrumental in large-scale detection and treatment of undernutrition. The World Health Organization (WHO) 2006 weight-for-height/length tables are diagnostic tools available to screen for acute malnutrition. Frontline workers (FWs) in a CMAM program in Dharavi, Mumbai, were using CommCare, a mobile application, for monitoring and case management of children in combination with the paper-based WHO simplified tables. A strategy was undertaken to digitize the WHO tables into the CommCare application. To measure differences in diagnostic accuracy in community-based screening for acute malnutrition, by FWs, using a mobile-based solution. Twenty-seven FWs initially used the paper-based tables and then switched to an updated mobile application that included a nutritional grade calculator. Human error rates specifically associated with grade classification were calculated by comparison of the grade assigned by the FW to the grade each child should have received based on the same WHO tables. Cohen kappa coefficient, sensitivity and specificity rates were also calculated and compared for paper-based grade assignments and calculator grade assignments. Comparing FWs (N = 14) who completed at least 40 screenings without and 40 with the calculator, the error rates were 5.5% and 0.7%, respectively (p < .0001). Interrater reliability (κ) increased to an almost perfect level (>.90), from .79 to .97, after switching to the mobile calculator. Sensitivity and specificity also improved significantly. The mobile calculator significantly reduces an important component of human error in using the WHO tables to assess acute malnutrition at the community level.

Role of endoscopic ultrasound-guided fine needle aspiration in the diagnosis of mass lesions.

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is an accurate technique for sampling the pancreas and mediastinum; however, limited data are available for other mass lesions. The aim of this study was to explore the value of EUS-FNA in the differential diagnosis of all mass lesions. Data from patients who underwent EUS-FNA for the diagnosis of mass lesions, including pancreatic, mediastinal, celiac and retroperitoneal lesions were retrospectively analyzed. The accuracy was calculated by comparing the results of FNA with the results of pathological examination or follow-up surveillances in non-operated cases. A total of 150 cases were included. The location of the mass varied from the pancreas (n=62) to the mediastinum (n=29), gastrointestinal tract (n=36), celiac cavity and retroperitoneum (n=23). The sensitivity and Youdens index of EUS-FNA in the diagnosis of all lesions were 92.97% and 0.93 respectively. The accuracy of diagnosis of pancreatic, mediastinal, gastrointestinal, celiac and retroperitoneal lesions was 85.48, 89.66, 83.33 and 78.23%, respectively. Masses were categorized into parenchymal organs (n=66), luminal organs (n=36) and enlarged lymph nodes (n=33). Lesions in parenchymal organs were likely to be bigger than those in luminal organs (P=0.03) and enlarged lymph nodes (P=0.01). For solid and cystic masses, which constituted 63.3 and 14.7% of the total masses, no significant difference in diagnostic accuracy was observed (P=0.56); however, lesion sizes were significantly different between these two groups (P=0.04) and the majority of cystic masses were identified in women (P=0.03). Malignant lesions were more common in older (P=0.01) and male (P=0.03) patients. In conclusion, EUS-FNA is an effective tool in the diagnosis of unexplained mass lesions; it influences the management of patients by enabling the appropriate treatment to be identified.

Investigation into diagnostic accuracy of common strategies for automated perfusion motion correction.

Respiratory motion is a significant obstacle to the use of quantitative perfusion in clinical practice. Increasingly complex motion correction algorithms are being developed to correct for respiratory motion. However, the impact of these improvements on the final diagnosis of ischemic heart disease has not been evaluated. The aim of this study was to compare the performance of four automated correction methods in terms of their impact on diagnostic accuracy. Three strategies for motion correction were used: (1)independent translation correction for all slices, (2)translation correction for the basal slice with transform propagation to the remaining two slices assuming identical motion in the remaining slices, and (3)rigid correction (translation and rotation) for the basal slice. There were no significant differences in diagnostic accuracy between the manual and automatic motion-corrected datasets ([Formula: see text]). The area under the curve values for manual motion correction and automatic motion correction were 0.93 and 0.92, respectively. All of the automated motion correction methods achieved a comparable diagnostic accuracy to manual correction. This suggests that the simplest automated motion correction method (method 2 with translation transform for basal location and transform propagation to the remaining slices) is a sufficiently complex motion correction method for use in quantitative myocardial perfusion.

Cerebral CTA with Low Tube Voltage and Low Contrast Material Volume for Detection of Intracranial Aneurysms.

Multidetector row CTA has become the primary imaging technique for detecting intracranial aneurysms. Technical progress enables the use of cerebral CTA with lower radiation doses and contrast media. We evaluated the diagnostic accuracy of 80-kV(peak) cerebral CTA with 30 mL of contrast agent for detecting intracranial aneurysms. Two hundred four patients were randomly divided into 2 groups. Patients in group A (n = 102) underwent 80-kVp CTA with 30 mL of contrast agent, while patients in group B (n = 102) underwent conventional CTA (120 kVp, 60 mL of contrast agent). All patients underwent DSA. Image quality, diagnostic accuracy, and radiation dose between the 2 groups were compared. Diagnostic image quality was obtained in 100 and 99 patients in groups A and B, respectively (P = .65). With DSA as reference standard, diagnostic accuracy on a per-aneurysm basis was 89.9% for group A and 93.9% for group B. For evaluating smaller aneurysms (<3 mm), the diagnostic accuracy of groups A and B was 86.3% and 90.8%, respectively. There was no difference in diagnostic accuracy between each CTA group and DSA (all, P > .05) or between the 2 CTA groups (all, P > .05). The effective dose in group A was reduced by 72.7% compared with group B. In detecting intracranial aneurysms with substantial radiation dose and contrast agent reduction, 80-kVp/30-mL contrast CTA provides the same diagnostic accuracy as conventional CTA.

Diagnosis and Treatment of Intracranial Aneurysms with 320-Detector Row Volumetric Computed Tomography Angiography

The objective of the study was to determine the clinical utility of 320-detector row volume-computed tomographic angiography (VCTA) in the management of intracranial aneurysms. Between February 2011 and May 2015, 550 patients successfully underwent 320-detector row VCTA for suspected intracranial aneurysms. Three-dimensional (3D) digital subtraction angiography (DSA) was used as the ultimate reference standard, and the sensitivity, specificity, and accuracy of both nonsubtracted and subtracted VCTA in identifying aneurysms were analyzed. Nonsubtracted VCTA identified 417 aneurysms (2 false-positive readings, 12 false-negative readings). The diagnostic sensitivity, specificity, and accuracy of non-subtracted VCTA, on a per-aneurysm basis, were 97.2%, 99.0%, and 97.6%, respectively. Subtracted VCTA identified 426 aneurysms (2 false-positive readings, 3 false-negative readings). The sensitivity, specificity, and accuracy of subtracted VCTA, on a per-aneurysm basis, were 99.3%, 99.0%, and 99.2%, respectively. No differences in diagnostic accuracy were found between subtracted VCTA and 3D DSA. Nonsubtracted VCTA, however, was observed to be significantly less sensitive than 3D DSA and subtracted VCTA. Twenty-six aneurysm cases were referred for surgical treatment based on VCTA imaging. All aneurysms were deemed completely occluded during surgical clipping. On the basis of VCTA imaging, 299 aneurysms were found suitable for endovascular coiling, of which 293 aneurysms (98%) were treated successfully. The 320-detector row subtracted VCTA technique is an effective, first-line diagnostic imaging modality for surgical and endovascular treatment of aneurysms. The nonsubtracted VCTA was less accurate than the subtracted VCTA, especially for intracranial aneurysms adjoining bone tissue.

Magnetic Resonance Angiography in the Diagnosis of Cerebral Arteriovenous Malformation and Dural Arteriovenous Fistulas: Comparison of Time-Resolved Magnetic Resonance Angiography and Three Dimensional Time-of-Flight Magnetic Resonance Angiography.

BackgroundTraditional digital subtraction angiography (DSA) is currently the gold standard diagnostic method for the diagnosis and evaluation of cerebral arteriovenous malformation (AVM) and dural arteriovenous fistulas (dAVF).ObjectivesThe aim of this study was to analyze different less invasive magnetic resonance angiography (MRA) images, time-resolved MRA (TR-MRA) and three-dimensional time-of-flight MRA (3D TOF MRA) to identify their diagnostic accuracy and to determine which approach is most similar to DSA.Patients and MethodsA total of 41 patients with AVM and dAVF at their initial evaluation or follow-up after treatment were recruited in this study. We applied time-resolved angiography using keyhole (4D-TRAK) MRA to perform TR-MRA and 3D TOF MRA examinations simultaneously followed by DSA, which was considered as a standard reference. Two experienced neuroradiologists reviewed the images to compare the diagnostic accuracy, arterial feeder and venous drainage between these two MRA images. Inter-observer agreement for different MRA images was assessed by Kappa coefficient and the differences of diagnostic accuracy between MRA images were evaluated by the Wilcoxon rank sum test.ResultsAlmost all vascular lesions (92.68%) were correctly diagnosed using 4D-TRAK MRA. However, 3D TOF MRA only diagnosed 26 patients (63.41%) accurately. There were statistically significant differences regarding lesion diagnostic accuracy (P = 0.008) and venous drainage identification (P < 0.0001) between 4D-TRAK MRA and 3D TOF MRA. The results indicate that 4D-TRAK MRA is superior to 3D TOF MRA in the assessment of lesions.ConclusionCompared with 3D TOF MRA, 4D-TRAK MRA proved to be a more reliable screening modality and follow-up method for the diagnosis of cerebral AVM and dAVF.

Virtual monoenergetic reconstruction of contrast-enhanced dual energy CT at 70 keV maximizes mural enhancement in acute small bowel obstruction

PurposeIn patients with small bowel obstruction (SBO), it is challenging to detect early ischemia. The purpose of this study is to evaluate the quantitative and qualitative benefits of virtual monoenergetic image (VMI) reconstruction in the assessment of small bowel mural enhancement on dual source dual energy computed tomography (CT) scans of the abdomen. Materials and methodsInstitutional review board approval was obtained, for this retrospective analysis. 72 consecutive patients with acute SBO were scanned using a second generation 128-slice dual source, CT system. Images were reconstructed at VMI energy levels from 40 to 110keV in 10keV increments and were analysed quantitatively and qualitatively. Contrast to noise ratios (CNR) and signal to noise ratios (SNR) for mural enhancement were recorded for all VMI datasets and compared to conventional polychromatic images (PCI) at 120kVp. Subjective analysis of mural enhancement on VMI and PCI was performed by 3 blinded readers. ResultsOptimal CNR values for small intestinal mural enhancement were observed at 70keV. Qualitative assessment revealed that there was no statistical difference in diagnostic accuracy between VMI and PCI. All readers reported improved confidence when assessing the contrast enhancement on the 70keV VMI dataset and in our series, 2 additional cases of ischemia were identified on this reconstruction. ConclusionContrast-enhanced dual source dual energy CT with VMI reconstruction at 70keV maximizes the CNR of small bowel mural enhancement and increases the overall diagnostic confidence in assessing mural enhancement in patients with SBO.

The Development of Expertise in Radiology: In Chest Radiograph Interpretation, "Expert" Search Pattern May Predate "Expert" Levels of Diagnostic Accuracy for Pneumothorax Identification.

Purpose To investigate the development of chest radiograph interpretation skill through medical training by measuring both diagnostic accuracy and eye movements during visual search. Materials and Methods An institutional exemption from full ethical review was granted for the study. Five consultant radiologists were deemed the reference expert group, and four radiology registrars, five senior house officers (SHOs), and six interns formed four clinician groups. Participants were shown 30 chest radiographs, 14 of which had a pneumothorax, and were asked to give their level of confidence as to whether a pneumothorax was present. Receiver operating characteristic (ROC) curve analysis was carried out on diagnostic decisions. Eye movements were recorded with a Tobii TX300 (Tobii Technology, Stockholm, Sweden) eye tracker. Four eye-tracking metrics were analyzed. Variables were compared to identify any differences between groups. All data were compared by using the Friedman nonparametric method. Results The average area under the ROC curve for the groups increased with experience (0.947 for consultants, 0.792 for registrars, 0.693 for SHOs, and 0.659 for interns; P = .009). A significant difference in diagnostic accuracy was found between consultants and registrars (P = .046). All four eye-tracking metrics decreased with experience, and there were significant differences between registrars and SHOs. Total reading time decreased with experience; it was significantly lower for registrars compared with SHOs (P = .046) and for SHOs compared with interns (P = .025). Conclusion Chest radiograph interpretation skill increased with experience, both in terms of diagnostic accuracy and visual search. The observed level of experience at which there was a significant difference was higher for diagnostic accuracy than for eye-tracking metrics. (©) RSNA, 2016 Online supplemental material is available for this article.

Estimating the reliability of eyewitness identifications from police lineups

Laboratory-based mock crime studies have often been interpreted to mean that (i) eyewitness confidence in an identification made from a lineup is a weak indicator of accuracy and (ii) sequential lineups are diagnostically superior to traditional simultaneous lineups. Largely as a result, juries are increasingly encouraged to disregard eyewitness confidence, and up to 30% of law enforcement agencies in the United States have adopted the sequential procedure. We conducted a field study of actual eyewitnesses who were assigned to simultaneous or sequential photo lineups in the Houston Police Department over a 1-y period. Identifications were made using a three-point confidence scale, and a signal detection model was used to analyze and interpret the results. Our findings suggest that (i) confidence in an eyewitness identification from a fair lineup is a highly reliable indicator of accuracy and (ii) if there is any difference in diagnostic accuracy between the two lineup formats, it likely favors the simultaneous procedure.

Urinary Biomarkers for Diagnosis of Bladder Cancer: A Systematic Review and Meta-analysis.

Urinary biomarkers may be a useful alternative or adjunct to cystoscopy for diagnosis of bladder cancer. To systematically review the evidence on the accuracy of urinary biomarkers for diagnosis of bladder cancer in adults who have signs or symptoms of the disease or are undergoing surveillance for recurrent disease. Ovid MEDLINE (January 1990 through June 2015), Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and reference lists. 57 studies that evaluated the diagnostic accuracy of quantitative or qualitative nuclear matrix protein 22 (NMP22), qualitative or quantitative bladder tumor antigen (BTA), fluorescence in situ hybridization (FISH), fluorescent immunohistochemistry (ImmunoCyt [Scimedx]), and Cxbladder (Pacific Edge Diagnostics USA) using cystoscopy and histopathology as the reference standard met inclusion criteria. Case-control studies were excluded. Dual extraction and quality assessment of individual studies. Overall strength of evidence (SOE) was also assessed. Across biomarkers, sensitivities ranged from 0.57 to 0.82 and specificities ranged from 0.74 to 0.88. Positive likelihood ratios ranged from 2.52 to 5.53, and negative likelihood ratios ranged from 0.21 to 0.48 (moderate SOE for quantitative NMP22, qualitative BTA, FISH, and ImmunoCyt; low SOE for others). For some biomarkers, sensitivity was higher for initial diagnosis of bladder cancer than for diagnosis of recurrence. Sensitivity increased with higher tumor stage or grade. Studies that directly compared the accuracy of quantitative NMP22 and qualitative BTA found no differences in diagnostic accuracy (moderate SOE); head-to-head studies of other biomarkers were limited. Urinary biomarkers plus cytologic evaluation were more sensitive than biomarkers alone but missed about 10% of bladder cancer cases. Restricted to English-language studies; no search for studies published only as abstracts; statistical heterogeneity present in most analyses; few studies for qualitative NMP22, quantitative BTA, and Cxbladder; and methodological shortcomings in almost all studies. Urinary biomarkers miss a substantial proportion of patients with bladder cancer and are subject to false-positive results in others. Accuracy is poor for low-stage and low-grade tumors. Agency for Healthcare Research and Quality. (PROSPERO registration number: CRD42014013284).

Abstract 10357: The Usefulness of Home Blood Pressure Measurement in the Diagnosis of Hypertension: A Prospective Multicenter Study

Introduction: The major hypertension guidelines suggest methods for diagnosing hypertension by measuring the 24-hour ambulatory blood pressure (ABP) or home blood pressure (HBP) if hypertension is suspected. Hypothesis: there is no consensus of cut off values for HBP as the criterion for hypertension and also optimal duration of home blood pressure measurement (HBPM). Methods: 319 suspected hypertension patients (systolic blood pressure ≥140 mmHg or diastolic blood pressure ≥90 mmHg, average value of three times measurements of blood pressure in the office) were included in four university hospital. The blood pressure (BP) measurement taken by patients in his/her home with HBPM device (Watch BP Home, Microlife, Swiss) and measured three times with one minute interval at morning and evening for 7 days. The 24-hour ambulatory blood pressure measurement (ABPM) was performed by Mobil-O-Graph (IEM. GmbH, Germany). The device was set to obtain BP readings at 30-minute intervals during the day and night. The definition of hypertension was as follows, SBP ≥135 mmHg or DBP ≥85 mmHg for HBPM and SBP ≥130 mmHg or DBP ≥85 mmHg for ABPM. For the analysis for diagnostic accuracy of HBPM, we used ABPM as a reference standard for the diagnosis of hypertension. Results: We decided to exclude 53 patients due to dropout or lack of valid BP measurement (valid leadings &lt;70% of tried measurements of ABPM and less than 5-days HBPM). Finally we analyzed BP measurement data of 266 patients. Dropout or invalid BP measurement was more common in ABPM than HBPM. HBP was measured at least 6 days in more than 90% patients and white coat hypertension was diagnosed more frequently in the HBPM. HBPM had a more than 98.6% positive predictive value and 46.8% negative predictive value for the diagnosis of hypertension when put the criteria on ABPM. There are no difference of diagnostic accuracy for the diagnosis of hypertension according to the 5-day, 6-day and 7-day HBPM. Conclusions: A 5-day HBPM is enough for the diagnosis of hypertension considering ABPM as a reference. The cut off value of hypertension in HBPM is same to the current guideline values (135/85 mmHg) in this study. HBPM is an effective and available method for the diagnosis of hypertension in suspected hypertensive patients.

Progressing Toward a Cohesive Pediatric 18F-FDG PET/MR Protocol: Is Administration of Gadolinium Chelates Necessary?

With the increasing availability of integrated PET/MR scanners, the utility and need for MR contrast agents for combined scans is questioned. The purpose of our study was to evaluate whether administration of gadolinium chelates is necessary for evaluation of pediatric tumors on (18)F-FDG PET/MR images. First, in 119 pediatric patients with primary and secondary tumors, we used 14 diagnostic criteria to compare the accuracy of several MR sequences: unenhanced T2-weighted fast spin-echo imaging; unenhanced diffusion-weighted imaging; and-before and after gadolinium chelate contrast enhancement-T1-weighted 3-dimensional spoiled gradient echo LAVA (liver acquisition with volume acquisition) imaging. Next, in a subset of 36 patients who had undergone (18)F-FDG PET within 3 wk of MRI, we fused the PET images with the unenhanced T2-weighted MR images (unenhanced (18)F-FDG PET/MRI) and the enhanced T1-weighted MR images (enhanced (18)F-FDG PET/MRI). Using the McNemar test, we compared the accuracy of the two types of fused images using the 14 diagnostic criteria. We also evaluated the concordance between (18)F-FDG avidity and gadolinium chelate enhancement. The standard of reference was histopathologic results, surgical notes, and follow-up imaging. There was no significant difference in diagnostic accuracy between the unenhanced and enhanced MR images. Accordingly, there was no significant difference in diagnostic accuracy between the unenhanced and enhanced (18)F-FDG PET/MR images. (18)F-FDG avidity and gadolinium chelate enhancement were concordant in 30 of the 36 patients and 106 of their 123 tumors. Gadolinium chelate administration is not necessary for accurate diagnostic characterization of most solid pediatric malignancies on (18)F-FDG PET/MR images, with the possible exception of focal liver lesions.

Transient and 2-Dimensional Shear-Wave Elastography Provide Comparable Assessment of Alcoholic Liver Fibrosis and Cirrhosis

Alcohol abuse causes half of all deaths from cirrhosis in the West, but few tools are available for noninvasive diagnosis of alcoholic liver disease. We evaluated 2 elastography techniques for diagnosis of alcoholic fibrosis and cirrhosis; liver biopsy with Ishak score and collagen-proportionate area were used as reference. We performed a prospective study of 199 consecutive patients with ongoing or prior alcohol abuse, but without known liver disease. One group of patients had a high pretest probability of cirrhosis because they were identified at hospital liver clinics (in Southern Denmark). The second, lower-risk group, was recruited from municipal alcohol rehabilitation centers and the Danish national public health portal. All subjects underwent same-day transient elastography (FibroScan), 2-dimensional shear wave elastography (Supersonic Aixplorer), and liver biopsy after an overnight fast. Transient elastography and 2-dimensional shear wave elastography identified subjects in each group with significant fibrosis (Ishak score ≥3) and cirrhosis (Ishak score ≥5) with high accuracy (area under the curve ≥0.92). There was no difference in diagnostic accuracy between techniques. The cutoff values for optimal identification of significant fibrosis by transient elastography and 2-dimensional shear wave elastography were 9.6 kPa and 10.2 kPa, and for cirrhosis 19.7 kPa and 16.4 kPa. Negative predictive values were high for both groups, but the positive predictive value for cirrhosis was >66% in the high-risk group vs approximately 50% in the low-risk group. Evidence of alcohol-induced damage to cholangiocytes, but not ongoing alcohol abuse, affected liver stiffness. The collagen-proportionate area correlated with Ishak grades and accurately identified individuals with significant fibrosis and cirrhosis. In a prospective study of individuals at risk for liver fibrosis due to alcohol consumption, we found elastography to be an excellent tool for diagnosing liver fibrosis and for excluding (ruling out rather than ruling in) cirrhosis.

Nucleic acid amplification techniques (NAATs) for early diagnosis of HIV-1 and HIV-2 infections

This is the protocol for a review and there is no abstract. The objectives are as follows: Our primary objective is to assess the diagnostic accuracy (sensitivity and specificity) of NAATs (both quantitative and qualitative) for early diagnosis of people of all ages with suspected HIV-1 and -2 infections. We hypothesize that their accuracy for early diagnosis will be as good as the diagnosis at a later stage. We furthermore hypothesize that there will be no differences in diagnostic accuracy between the different molecular tests when evaluated against the same reference standard. We defined early detection as a period that is consistently between one and three weeks (Busch 1997; Fiebig 2003). The secondary objective of this review is to assess the influence of sources of heterogeneity on the diagnostic accuracy of tests performed, in particular the type of HIV (HIV-1 or HIV-2), different cut-off values, different samples, the healthcare setting, age of the participants, differences in timing of the tests, to investigate how the time of testing relates to accuracy; and study design features.