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PubMed1987

Improved sex-specific criteria of left ventricular hypertrophy for clinical and computer interpretation of electrocardiograms: validation with autopsy findings.

In a previous study of 543 patients we developed, using echocardiographic left ventricular mass as the reference standard, two new sets of criteria that improve the electrocardiographic diagnosis of left ventricular hypertrophy (LVH). One set of criteria, which is suitable for routine clinical use, detects LVH when the sum of voltage in RaVL + SV3 (Cornell voltage) exceeds 2.8 mV in men and 2.0 mV in women. The second set of criteria, suitable for use in interpretation of the computerized electrocardiogram, uses logistic regression models based on electrocardiographic and demographic variables with independent predictive value for LVH, with separate equations for patients in sinus rhythm and atrial fibrillation. To test these criteria prospectively with use of a different reference standard, antemortem electrocardiograms were compared with left ventricular muscle mass measured at autopsy in 135 patients. Sensitivity of standard Sokolow-Lyon voltage (SLV) criteria (SV1 + RV5 or RV6 greater than 3.5 mV) for LVH was only 22%, but specificity was 100%. The Cornell voltage criteria improved sensitivity to 42%, while maintaining high specificity at 96%. Higher sensitivity (62%) was achieved by use of the new regression criteria, with a specificity of 92%. Overall test accuracy was 60% for SLV criteria, 68% for the Cornell voltage criteria, and 77% for the new regression criteria (p less than .005 vs SLV). We conclude that the Cornell voltage criteria improve the sensitivity of the electrocardiogram for detection of LVH and are easily applicable in clinical practice.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiomegaly↗
PubMed2001

The certification of SRM 1546--Meat Homogenate, a new reference material for nutrients in a high protein, high fat matrix.

In response to reference material needs expressed by the food industry and government regulators, the National Institute of Standards and Technology (NIST) has developed a new Standard Reference Material (SRM) consisting of a canned meat product with certified and reference values for a large number of constituents. SRM 1546 Meat Homogenate consists of a mixture of finely ground pork and chicken prepared and canned by a commercial process. NIST determined the concentration levels of cholesterol, sodium, calcium, iron, and seven fatty acids in this SRM using well defined methods and procedures. These analytes as well as 34 other constituents or properties were determined in an interlaboratory comparison exercise involving 21 laboratories, most of which are associated with the National Food Processors Association (NFPA) Food Industry Analytical Chemists Subcommittee (FIACS). From statistical analysis of the data, NIST assigned certified concentrations for the eleven analytes measured at NIST and reference concentrations for the proximates, six additional fatty acids, seven minerals, and seven water-soluble vitamins. Information values without uncertainties are provided for the concentrations of six additional constituents for which the uncertainties could not adequately be assessed. SRM 1546 will provide laboratories with a means to evaluate the accuracy of the methods they use to assign nutrient levels to processed meats and similar products.

Animals↗
PubMed2002

Serologic herpes testing in the real world: validation of new type-specific serologic herpes simplex virus tests in a public health laboratory.

BACKGROUND: Serologic testing for herpes simplex virus type-2 (HSV-2) is being implemented in sexually transmitted disease (STD) clinics. GOAL: To determine the performance characteristics of two HSV-2 type-specific serologic assays in a public health laboratory. STUDY DESIGN: Sera stored from a cross-sectional study were tested with the Meridian Diagnostics and Focus Technologies HSV-2 ELISA tests and a type-specific strip immunoblot assay (Chiron Corp.) was used as the reference standard. RESULTS: Prevalence of HSV-2 infection in this sample was 44%. Compared to the reference standard, the sensitivity of the Meridian Diagnostics HSV-2 test was 95.5% (95% CI 83.3, 99.2) and specificity was 98.2% (95% CI 89.0, 99.9). The Focus Technologies test yielded 97.7% (95% CI 86.5, 99.9) sensitivity and 94.5% (95% CI 83.9, 98.6) specificity. CONCLUSIONS: The performance of these HSV-2 type-specific serologic assays was adequate to support their use in high prevalence populations, such as STD clinic patients.

Adolescent↗
PubMed2006

Ultra-low flow nanospray for the normalization of conventional liquid chromatography/mass spectrometry through equimolar response: standard-free quantitative estimation of metabolite levels in drug discovery.

Nanospray experiments were performed on an ensemble of drug molecules and their commonly known metabolites to compare performance with conventional electrospray ionization (ESI) and to evaluate equimolar response capabilities. Codeine, dextromethorphan, tolbutamide, phenobarbital, cocaine, and morphine were analyzed along with their well-known metabolites that were formed via hydroxylation, dealkylation, hydrolysis, and glucuronidation. Nanospray exhibited a distinct trend toward equimolar response when flow rate was reduced from 25 nL/min to less than 10 nL/min. A more uniform response between the parent drug and the corresponding metabolites was obtained at flow rates of 10 nL/min or lower. The largest discrepancy was within +/-50% for plasma samples. Nanospray was used as a calibrator for conventional ESI liquid chromatography/tandem mass spectrometry (LC/MS/MS) and normalization factors were applied to the quantitation of an acyl-glucuronide metabolite of a proprietary compound in rat plasma. A nanospray calibration method was developed with the standard curve of the parent drug to generate quantitative results for drug metabolites within +/-20% of that obtained with reference standards and conventional ESI. The nanospray method provides a practical solution for the quantitative estimation of drug metabolites in drug discovery when reference standards are not available.

Calibration↗
PubMed2002

Quantification of procyanidins in oral herbal medicinal products containing extracts of Crataegus species.

According to the European Pharmacopeia a photometric assay is used for the estimation of procyanidins in Crataegi fructus. This assay is also most commonly used for procyanidin analysis in herbal medicinal products (HMPs) containing extracts of hawthorn (Crataegus species). In order to find an appropriate method for the determination of oligomeric and polymeric procyanidins by analysing various preparations containing extracts of Crataegus, the Ph. Eur.-method was compared to an HPLC-method with chemical reaction detection (HPLC-CRD-method) and another conventional photometric assay using 4-dimethylamino-cinnamic-aldehyde (DMACA). Total procyanidins estimates obtained with the pharmacopeial method were, depending on the reference standard used, at least more than 50% higher than those obtained with the DMACA-assay. The determination of individual procyanidins could only be achieved by HPLC-CRD. Monomeric, dimeric, and trimeric procyanidins could be separated and detected individually, whereas no HPLC separation was possible for higher polymeric compounds. However, these compounds could be analysed as co-eluting groups. Using the DMACA method for the estimation of total oligomeric procyanidins and the HPLC-CRD method for quantification of the mono- up to trimeric procyanidins, some market leading herbal medicinal products from Germany containing extracts Crataegus species (C. monogyna Jacq., C. laevigata D.C., C. pentagyna Waldst. et Kit., C. nigra Waldst. et Kit, C. azarolus L.) were analysed. Procyanidin B2 (epicatechin-(4 beta-->8)-epicatechin) was isolated from Aesculus hippocastanum fruit shells as reference standard for calibration purposes. The structure elucidation was carried out by by means of MS and 1H-NMR. Quantitative 1H-NMR spectroscopy (qNMR) was applied for purity assessment.

Antioxidants↗
PubMed1993

Rapid detection of herpes simplex virus in culture by in situ hybridization.

Detection of herpes simplex virus (HSV) by a newly developed HSV-DNA in situ hybridization (ISH) technique (Diagnostic Hybrids, Inc., Athens, OH, USA) was compared with a reference standard that combines observation for cytopathic effect in shell vial cultures with subsequent identification of virus by staining with fluorescein-labeled HSV-specific monoclonal antibody. The new technique utilizes a probe consisting of an alkaline phosphatase direct labeled, cloned, single stranded DNA fragment that is common to HSV-1 and HSV-2. Both methods include enhancement of infection by centrifugation. In concurrent testing of 98 freshly collected specimens, HSV was detected in 17 by culture and 16 by ISH. In testing of 57 frozen positive specimens, HSV was detected in 54 by culture and 53 by ISH. Of the total isolates, 22 were HSV-1 and 49 were HSV-2. HSV was detected after 24 hrs of incubation by the DNA probe technique. Using the shell vial method as a reference standard, the new HSV-DNA ISH method had a sensitivity of 97.2%, specificity of 100%, positive predictive value of 100%, and a negative predictive value of 97.7%. HSV-DNA ISH appears to be a practical, sensitive, and specific technique for detection of HSV.

Cytopathogenic Effect, Viral↗
PubMed2004

[Evaluation of experimental cartilage lesions with ultrahigh-resolution multi-slice-CT in comparison to histology].

PURPOSE: Histologic validation of ultrahigh-resolution multi-slice (MS)-CT for the evaluation of focal, experimental cartilage lesions with special regard to the subchondral bone. Testing of micro-CT ( micro CT) as alternative reference standard. METHODS: 32 experimental cartilage lesions in bovine patellae were imaged surrounded by air (MS-CT-air) and immersed in a contrast material solution (MS-CT-CM) with MS-CT (collimation 2 x 0,5 mm). After the micro CT (8 micro m-voxelsite) examination in three specimen and histologic work-up of 29 specimen two radiologist graded the defects on MS-CT images in consensus (subchondral bone involvement yes or no) and results were compared to the results of histomorphometry and micro CT. RESULTS: The MS-CT-air and -CM had an accuracy of 94 % (30/32) and 88 % (28/32), respectively. MS-CT-air led to one false-positive (remaining cartilage: = 0,1 mm) and false-negative result, each. MS-CT-CM showed false-positive results if the remaining cartilage was < 0,3 mm thick (n = 4), i. e. showed subchondral bone involvement. Contrast-to-noise ratio was significantly higher in MS-CT-air compared to MS-CT-CM. micro CT yielded a clear depiction of cartilage defect depth in the three cases. CONCLUSION: MS-CT-air has a high accuracy in the depiction of focal cartilage defects. MS-CT-CM has a tendency to overestimate cartilage defect depth. micro CT could potentially serve as alternative reference standard to histology.

Animals↗
PubMed2006

Ovarian reserve tests for predicting fertility outcomes for assisted reproductive technology: the International Systematic Collaboration of Ovarian Reserve Evaluation protocol for a systematic review of ovarian reserve test accuracy.

BACKGROUND: The presence of a wide range of tests of ovarian reserve suggests that no single test provides a sufficiently accurate result. Many tests are used without reference to an evidence base. So far, individual studies conducted on these tests are too small to give precise estimates of prognostic accuracy. OBJECTIVES: To systematically assess the accuracy of the available tests of ovarian reserve in terms of prediction of fertility outcomes. SEARCH STRATEGY: The search will be conducted using the name of the respective index test being studied (as listed on the MESH database), if more than 2000 citations are listed, 'ovary' and or 'ovarian', 'fertility' and or 'reserve' will be combined with the original search term as required. Studies of the accuracy of tests of ovarian reserve will be obtained without language restrictions from 1980 to 2005 using the following electronic databases and Ovid software: MEDLINE, EMBASE, PUBmed, Biological extracts, Pascal, Cochrane Library (CDSR, DARE, CCTR, HTA), Best Evidence databases, SCISEARCH, Conference Proceedings (ISI Proceedings, Healthstar, Current Contents, Science Citation Index, Cancerlit and Econlit and NHS Economic Evaluation database. The National Research Register, the Medical Research Council's Clinical Trials Register, MEDION, DARE, and the US Clinical Trials register. SELECTION CRITERIA: Studies will be selected if accuracy of tests are compared with a reference standard and include data that can be abstracted into a two-by-two table to calculate sensitivity and specificity. The studies to be included in this review will examine one of the following index 'tests' within a study population of women undergoing assisted reproductive technology: * Clinical variables--age, history of cancelled cycles. * Basal blood tests--follicle-stimulating hormone (FSH), lutenising hormone (LH), FSH:LH ratios, estradiol (E(2)), inhibin A and B, progesterone (P(4)), P(4):E(2) ratios, antimullerian hormone, testosterone, vascular endothelial growth factor, insulin-like growth factor-1:insulin-like growth factor binding protein-1 ratios. * Dynamic tests--clomiphene citrate challenge test, gonadotropin analogue stimulating test, exogenous FSH ovarian reserve test. * Ultrasound tests-antral follicle count, ovarian volume, ovarian stromal peak systolic velocity, including waveform and pulsatility index, ovarian follicular vascularity. * Histology--ovarian biopsy. Data collection and analysis Two independent reviewers will perform quality assessment and data extraction. Prognostic accuracy will be determined by calculating positive and negative likelihood ratios for the following outcomes or reference standards: live birth, ongoing pregnancy, clinical pregnancy, biochemical pregnancy, embryos available for transfer, eggs obtained at oocyte retrieval, cycles cancelled prior to oocyte retrieval. Main results and conclusions N/A.

Data Collection↗
PubMed2006

Interrater reliability in assessing quality of diagnostic accuracy studies using the QUADAS tool. A preliminary assessment.

RATIONALE AND OBJECTIVES: Quality Assessment of Diagnostic Accuracy Studies (QUADAS) is a new tool to measure the methodological quality of diagnostic accuracy studies in systematic reviews. We used data from a systematic review of magnetic resonance spectroscopy (MRS) in the characterization of suspected brain tumors to provide a preliminary evaluation of the inter-rater reliability of QUADAS. MATERIALS AND METHODS: A structured literature search identified 19 diagnostic accuracy studies. These publications were distributed randomly to primary and secondary reviewers for dual independent assessment. Reviewers recorded methodological quality by using QUADAS on a custom-designed spreadsheet. We calculated correlation, percentage of agreement, and kappa statistic to assess inter-rater reliability. RESULTS: Most studies in our review were judged to have used an accurate reference standard. Conversely, the MRS literature frequently failed to specify the length of time between index and reference tests or that the clinicians were unaware of the index test findings when reporting the reference standard. There was good correlation (rho = 0.78) between reviewers in assessment of the overall number of quality criteria met. However, mean agreement for individual QUADAS questions was only fair (kappa = 0.22) and ranged from no agreement beyond chance (kappa < 0) to moderate agreement (kappa = 0.58). CONCLUSION: Inter-rater reliability in our study was relatively low. Nevertheless, we believe that QUADAS potentially is a useful tool for highlighting the strengths and weaknesses of existing diagnostic accuracy studies. Low reliability suggests that different reviewers will reach different conclusions if QUADAS is used to exclude "low-quality" articles from meta-analyses. We discuss methods for improving the validity and reliability of QUADAS.

Brain Neoplasms↗
PubMed2004

Diagnosis of noncalcareous hydronephrosis: role of magnetic resonance urography and noncontrast computed tomography.

OBJECTIVES: To evaluate the role of magnetic resonance urography (MRU) and noncontrast computed tomography (NCCT) in the diagnosis of noncalcareous hydronephrosis when excretory urography (intravenous urography) is either contraindicated or inconclusive. METHODS: A total 108 consecutive patients with noncalcareous hydronephrosis were included in this study. In all patients, intravenous urography was either contraindicated or could not determine the diagnosis. In all patients, calculus obstruction was excluded by NCCT and all underwent heavily T2-weighted MRU. The final definitive diagnosis was established by retrograde or antegrade ureterography, endoscopy, or open surgery and was considered the reference standard for the diagnosis of obstruction. Normal kidneys in patients with unilateral obstruction were considered the reference standard for the absence of obstruction. The results of MRU were compared with those of NCCT regarding sensitivity, specificity, and overall accuracy. RESULTS: Of the 108 patients, 5 had bilateral obstruction and the remaining 103 had unilateral obstruction. Of the latter group, 5 had a solitary kidney; therefore, the total number of renal units was 211 (113 obstructed and 98 normal units). Ureteral strictures were identified by NCCT in 15 (28%) of 54 and by MRU in 45 (83%) of 54 patients. Bladder, ureter, or prostate tumors causing ureteral obstruction could be diagnosed in one half of the 54 patients with such tumors by NCCT (27 of 54) and in all but 2 patients by MRU (52 of 54). Both NCCT and MRU could identify all extraurinary causes of obstruction. Overall, of the 113 kidneys with noncalculus obstruction, the cause could be identified by MRU in 102 (sensitivity of 90%) and by NCCT in 47 (sensitivity of 42%), a difference of statistically significant value in favor of MRU (P <0.001). The specificity of T2-weighted MRU and NCCT was 100% and 99%, respectively (not a statistically significant difference). The overall accuracy of T2-weighted MRU and NCCT was 95% and 68%, respectively (P <0.001). CONCLUSIONS: In patients with ureteral obstruction in whom intravenous urography is not helpful and after NCCT has excluded stone disease, heavily T2-weighted MRU is a sensitive and specific method in the identification of the cause of obstruction.

Adult↗
PubMed1998

Accuracy of echocardiography for detection of aortic arch obstruction after stage I Norwood procedure.

BACKGROUND: Echocardiography has been widely used in postoperative assessment after stage I Norwood procedure, but its accuracy in detecting aortic arch obstruction (AAO) has not been determined. This study was designed to determine the accuracy of echocardiography in the diagnosis of AAO after stage I Norwood procedure, identify echocardiographic predictors of arch obstruction, and examine the time course of its development. METHODS: The records and echocardiography reports of 139 patients who survived stage I Norwood procedure were reviewed. Reference standard for the diagnosis of AAO was catheterization, surgery, or autopsy. RESULTS: AAO was diagnosed by reference standard criteria in 31 (22%) patients. Echocardiography correctly diagnosed AAO in 19 patients, missed the diagnosis in five, and wrongly predicted AAO in eight, yielding a 73% sensitivity, 92% specificity, 70% positive predictive value, and 88% accuracy. Moderate or severe right ventricular dysfunction, moderate or severe tricuspid regurgitation, and an abnormal abdominal aortic Doppler flow pattern were more common in patients with AAO. The probability of AAO developing within 6 months after stage I Norwood procedure was 21.1%, with a very small likelihood after that point. Beyond the first 30 days after surgery, the risk of death was higher in patients in whom AAO developed compared with those in whom it did not (relative risk 5.9, 95% confidence interval 2.7 to 13.2). CONCLUSIONS: Echocardiography is a highly specific modality in detecting AAO after stage I Norwood procedure but its sensitivity is limited. Because of the increased risk of death associated with AAO and because most obstructions develop between 1 and 6 months postoperatively, early cardiac catheterization with possible intervention should be considered in patients with moderate or severe right ventricular dysfunction, moderate or sever tricuspid regurgitation, or an abnormal abdominal Doppler flow pattern during that period.

Aortic Arch Syndromes↗
PubMed2004

Simulated annealing of microarray data reduces noise and enables cross-experimental comparisons.

Microarrays are a powerful tool for assessing the genome-wide induction of a transcriptional response to internal or external stimuli, but are not considered quantitatively rigorous (i.e., the signal intensity of hybridized probe is normally used to quantify relative transcript abundance). Thus, it is difficult, if not impossible, to accurately compare separate microarray experiments without a reference standard. However, even among replicated microarray experiments, each gene varies significantly in the amount of signal detected, suggesting no single gene would be appropriate as a standard. We propose and test a method to "align" experimental transcription profiles to a set of reference experiments using simulated annealing (SA), essentially using the relative positions of all genes as a reference standard. SA attempts to find a globally optimal adjustment factor for the relative expression level of each experimental gene expression signal, given a previously observed range of gene expression measurements. By defining a relative dynamic range of gene expression under control conditions for all genes, we can more accurately compare transcription profiles between separate experiments and, potentially, between species--enabling comparative transcriptomics. Testing SA on a published dataset, we find that it significantly reduces interexperimental variation, suggesting it holds promise to accomplish this goal.

Oligonucleotide Array Sequence Analysis↗
PubMed2005

Accuracy of parents in measuring body temperature with a tympanic thermometer.

BACKGROUND: It is now common for parents to measure tympanic temperatures in children. The objective of this study was to assess the diagnostic accuracy of these measurements. METHODS: Parents and then nurses measured the temperature of 60 children with a tympanic thermometer designed for home use (home thermometer). The reference standard was a temperature measured by a nurse with a model of tympanic thermometer commonly used in hospitals (hospital thermometer). A difference of >or= 0.5 degrees C was considered clinically significant. A fever was defined as a temperature >or= 38.5 degrees C. RESULTS: The mean absolute difference between the readings done by the parent and the nurse with the home thermometer was 0.44 +/- 0.61 degrees C, and 33% of the readings differed by >or= 0.5 degrees C. The mean absolute difference between the readings done by the parent with the home thermometer and the nurse with the hospital thermometer was 0.51 +/- 0.63 degrees C, and 72 % of the readings differed by >or= 0.5 degrees C. Using the home thermometer, parents detected fever with a sensitivity of 76% (95% CI 50-93%), a specificity of 95% (95% CI 84-99%), a positive predictive value of 87% (95% CI 60-98%), and a negative predictive value of 91% (95% CI 79-98 %). In comparing the readings the nurse obtained from the two different tympanic thermometers, the mean absolute difference was 0.24 +/- 0.22 degrees C. Nurses detected fever with a sensitivity of 94% (95 % CI 71-100 %), a specificity of 88% (95% CI 75-96 %), a positive predictive value of 76% (95% CI 53-92%), and a negative predictive value of 97% (95%CI 87-100 %) using the home thermometer. The intraclass correlation coefficient for the three sets of readings was 0.80, and the consistency of readings was not affected by the body temperature. CONCLUSIONS: The readings done by parents with a tympanic thermometer designed for home use differed a clinically significant amount from the reference standard (readings done by nurses with a model of tympanic thermometer commonly used in hospitals) the majority of the time, and parents failed to detect fever about one-quarter of the time. Tympanic readings reported by parents should be interpreted with great caution.

Adolescent↗
PubMed2004

Radiologic and patient-reported functional outcomes in an elderly cohort with conservatively treated distal radius fractures.

PURPOSE: There have been few prospective studies of elderly patients with conservatively treated distal radius fractures and little is known about the relationship between acceptable radiographic reduction and functional outcomes in this population. We hypothesized that acceptable fracture reduction (according to standard radiographic dorsal/volar tilt criteria) would be associated with better functional outcomes and greater satisfaction. METHODS: Seventy-four patients who were at least 50 years of age with conservatively managed distal radius fractures were recruited from 2 large urban emergency departments from January 2001 to December 2001. Patients with wrist fractures treated in the emergency department and discharged home were included; patients admitted to the hospital or who required surgical reduction were excluded. Standard lateral radiographs were taken after the final cast was removed. These were reviewed independently by a reference-standard musculoskeletal radiologist and the degree of dorsal/volar tilt was recorded. This value was dichotomized according to standard published dorsal/volar tilt criteria as acceptable (dorsal tilt <10 degrees or volar tilt <20 degrees ) or unacceptable (dorsal tilt >10 degrees or volar tilt >20 degrees ). The Medical Outcomes Study Short-Form 12 (SF-12); the Disabilities of the Arm, Shoulder, and Hand questionnaire; and a patient satisfaction survey were used to assess patient-reported outcomes 6 months after the injury. RESULTS: The average dorsal/volar tilt measured by the reference standard radiologist was 3.4 degrees (SD=13.6) dorsal; overall 47 patients (64%) were considered to have an acceptable radiographic reduction. Acceptable radiographic reduction was not associated with better generic physical or mental health status, lesser degrees of upper-extremity disability, or greater satisfaction with outcomes than was unacceptable reduction. Overall 44 of 74 patients (59%) reported being satisfied or very satisfied with their functional status at 6 months. CONCLUSIONS: Contrary to our hypotheses we found that acceptable radiographic reduction (according to dorsal/volar tilt criteria) was not associated with better self-reported functional outcomes or increased satisfaction at 6 months in elderly patients with conservatively treated distal radius fractures.

Aged↗
PubMed2005

Synthesis and pharmacological investigation of novel 1-substituted-4-phenyl-1,2,4-triazolo[4,3-a]quinazolin-5(4H)-ones as a new class of H1-antihistaminic agents.

A series of novel 1-substituted-4-phenyl-1,2,4-triazolo[4,3-a]quinazolin-5(4H)-ones 7 were synthesized by the cyclization of 2-hydrazino-3-phenylquinazolin-4(3H)-one 6 with various one carbon donors. The starting material 2-hydrazino-3-phenylquinazolin-4(3H)-one 6, was synthesized from aniline 1 by a novel innovative route. When tested for their in vivo H(1)-antihistaminic activity on conscious guinea pigs all the test compounds protected the animals from histamine induced bronchospasm significantly, whereas the compound 1-methyl-4-phenyl-1,2,4-triazolo[4,3-a]quinazolin-5(4H)-one 7b (percentage protection 70.7%) was found to be equipotent with the reference standard chlorpheniramine maleate (percentage protection 71%). These compounds show negligible sedation ( approximately 5%) when compared to the reference standard (26%). Hence they could serve as prototype molecules for future development.

Animals↗
PubMed1998

A two-term MEDLINE search strategy for identifying randomized trials in obstetrics and gynecology.

OBJECTIVE: To develop and test a simple MEDLINE search strategy for identification of randomized controlled trials (RCTs) in obstetrics and gynecology. METHODS: To develop our search strategy, we asked clinicians in our department to indicate, from a list of search terms, the terms they would use to identify RCTs in MEDLINE. The two most common terms, controlled-clinical-trial (publication type) and randomized-controlled-trial (publication type), were combined with the link word, OR, and then used to identify RCTs in four obstetrics and gynecology journals for the years 1975, 1980, 1985, 1990, and 1995. Concurrently, a handsearch of these same journals and years was performed to identify RCTs. The sensitivity and precision of MEDLINE and handsearch were calculated using the total number of RCTs identified by both methods as a reference standard. Sensitivity is the RCTs identified by search strategy as a percentage of all RCTs identified by reference standard. Precision is the RCTs identified by a search strategy as a percentage of all articles identified by it. RESULTS: The overall sensitivity of our MEDLINE search strategy was 72.5%, and the precision was 83.4%. Over 2 decades, sensitivity of our MEDLINE search increased from 0% to 94.9% (P < .001), while its precision dropped from 100% to 75.5% (P=.003). For 1990 and 1995 combined, sensitivity and precision of our MEDLINE search strategy were 90.3% and 79.6%, respectively. Overall sensitivity for handsearch was 96.5%; its precision was 5.0%. Over 2 decades, the sensitivity of handsearch dropped insignificantly from 100% to 92.3% (P=.05), while the precision increased from 2.6% to 6.3% (P < .001). CONCLUSION: Our simple MEDLINE search strategy has a high sensitivity and precision, especially in more recent years. Obstetricians and gynecologists may use it to search quickly for RCTs to guide patient care.

Gynecology↗
PubMedDate not supplied

Evaluation of a non-isotopic polymerase chain reaction-based assay to detect and predict treatment failure of Plasmodium vivax malaria in travellers.

With the emergence of chloroquine-resistant Plasmodium vivax (CRPV), new tests to detect P. vivax and predict response to therapy would be useful for clinical and research applications. We performed a 'blinded' evaluation of a non-isotopic (colourimetric) polymerase chain reaction (PCR) based assay (Digene SHARP Signal System) compared with microscopy and PCR/radiometric probe hybridization of ribosomal ribonucleic acid genes (RPH) for the detection of P. vivax malaria in 182 febrile travellers. Compared with PCR/RPH as the reference standard, the colourimetric assay had a sensitivity of 100% and specificity of 98%. Using microscopy as the reference standard, 84 of 87 patients with P. vivax infection had a positive colourimetric assay. The 3 patients with a negative assay were subsequently shown to be infected with P. ovale as determined by PCR/RPH. In a subset of patients followed longitudinally, the colourimetric assay was positive in 5 of 13 patients 6 or more days after initiation of therapy. Of these 5 patients, 4 were subsequently demonstrated to be infected with CRPV as determined by treatment failure in vivo and/or chloroquine blood levels. A positive assay result 6 or more days after initiation of therapy was associated with subsequent treatment failure (P < 0.01). This non-isotopic assay is a sensitive, specific, and rapid method for the detection of P. vivax PCR products and may prove useful in predicting treatment failure.

Antimalarials↗
PubMed2002

Use of plasma aldosterone concentration-to-plasma renin activity ratio as a screening test for primary aldosteronism. A systematic review of the literature.

The aldosterone-renin ratio is widely used to screen for primary aldosteronism. We conducted a systematic review of the literature to establish the test characteristics (sensitivity, specificity, likelihood ratios at different cutoff values) of the aldosterone-renin ratio used in screening for primary aldosteronism in subjects with presumed essential hypertension. We searched Medline, EMBASE, and Current Contents databases, bibliographies of retrieved papers, and personal files for all reports published from January 1966 to October 2001. We consulted experts to identify additional published and unpublished reports. We included prospective studies of the ratio as a screening test for primary aldosteronism, without applying language or data availability restrictions. We excluded retrospective studies, case reports, and duplicate or preliminary reports. Working independently, we selected the articles, assessed their quality, and extracted their data. Data extracted included sample size and care setting, description of the testing conditions, description of the confirmatory tests, and the test characteristics of the ratio (sensitivity, specificity, likelihood ratios at different cutoff values). This review includes 16 studies with 3136 participants. None of the studies evaluated the aldosterone-renin ratio and the reference standard independently of each other; only two studies evaluated patients who had a "negative" ratio with the reference standard. Only 16.7% of the subjects had both the ratio and the confirmatory test performed. Ratio cutoff values ranged from 200 to 2774 pmol/L per ng/mL per hour. None of the studies provided valid estimates of the aldosterone-renin ratio test characteristics. There are no published valid estimates of the test characteristics of the aldosterone-renin ratio when used as a screening test for primary aldosteronism in patients with presumed essential hypertension.

Aldosterone↗