Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Data Accuracy”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 991 records · Page 55Linked to original sources
PubMed1999

Performance of a Fourier-based program for three-dimensional reconstruction of the mitral annulus on application to sparse, noisy data.

OBJECTIVES: We investigated the accuracy of mitral annular reconstruction from noisy, sparse data typical of three-dimensional (3D) transthoracic echocardiograms. BACKGROUND: Our Fourier-based method for reconstructing the annulus from dense, accurate 3D transesophageal echo (TEE) data has been validated in vitro with four harmonics in the x, y, and z coordinates (4,4,4). METHODS: Thirteen mitral annuli were reconstructed from 'complete' 3D TEE data using four harmonics (4,4,4) and used to measure area, eccentricity. height, perimeter, and interpeak and intervalley distances; these were the 'true values'. To simulate transthoracic echo data, the TEE data sets were reduced evenly and unevenly (randomly). The complete and reduced data sets were used to reconstruct the annuli using three sets of fitting parameters: (4,4,4), (1,1,3), and (1,1,4). The resulting size and shape measurements were compared with true values. RESULTS: Regardless of the fitting parameters used, area, 2D perimeter, and 3D perimeter measurements were more accurate using reconstructions from evenly-reduced than randomly-reduced data sets (p < 0.006), and depended significantly on both data density (p < 0.015 for all) and data distribution (p < 0.02 for all). Perimeter, height, and eccentricity of the reconstructed annuli were more accurately measured using four harmonics (4,4,4). CONCLUSIONS: Mitral annuli can be reconstructed from sparse, noisy data using the (4,4,4) fit if at least 25 points are obtained from evenly distributed imaging planes. These results suggest that detailed analysis of mitral annular size and shape can be made accurately from 3D transthoracic echocardiograms.

Case-Control Studies↗
PubMed2000

Wavelet domain de-noising of time-courses in MR image sequences.

Magnetic resonance images acquired with high temporal resolution often exhibit large noise artifacts, which arise from physiological sources as well as from the acquisition hardware. These artifacts can be detrimental to the quality and interpretation of the time-course data in functional MRI studies. A class of wavelet-domain de-noising algorithms estimates the underlying, noise-free signal by thresholding (or 'shrinking') the wavelet coefficients, assuming the underlying temporal noise of each pixel is uncorrelated and Gaussian. A Wiener-type shrinkage algorithm is developed in this paper, for de-noising either complex- or magnitude-valued image data sequences. Using the de-correlation properties of the wavelet transform, as elucidated by Johnstone and Silverman, the assumption of i.i.d. Gaussian noise can be abandoned, opening up the possibility of removing colored noise. Both wavelet- and wavelet-packet based algorithms are developed, and the Wiener method is compared to the traditional Hard and Soft wavelet thresholding methods of Donoho and Johnstone. The methods are applied to two types of data sets. In the first, an artificial set of complex-valued images was constructed, in which each pixel has a simulated bimodal time-course. Gaussian noise was added to each of the real and imaginary channels, and the noise removed from the complex image sequence as well as the magnitude image sequence (where the noise is Rician). The bias and variance between the original and restored paradigms was estimated for each method. It was found that the Wiener method gives better balance in bias and variance than either Hard or Soft methods. Furthermore, de-noising magnitude data provides comparable accuracy of the restored images to that obtained from de-noising complex data. In the second data set, an actual in vivo complex image sequence containing unknown physiological and instrumental noise was used. The same bimodal paradigm as in the first data set was added to pixels in a small localized region of interest. For the paradigm investigated here, the smooth Daubechies wavelets provide better de-noising characteristics than the discontinuous Haar wavelets. Also, it was found that wavelet packet de-noising offers no significant improvement over the computationally more efficient wavelet de-noising methods. For the in vivo data, it is desirable that the groups of "activated" time-courses are homogeneous. It was found that the internal homogeneity of the group of time-courses increases when de-noising is applied. This suggests using de-noising as a pre-processing tool for both exploratory and inferential data analysis methods in fMRI.

Journal Article↗
PubMed2003

Diagnostic value of single versus dual chamber electrograms recorded from an implantable defibrillator.

INTRODUCTION: The clinical utility of ventricular electrograms in comparison to atrial and ventricular electrograms in diagnosing the type of tachycardias recorded by an implantable defibrillator has not been addressed from the standpoint of a clinician's diagnostic accuracy and confidence in that diagnosis. METHODS: Fifty-two tachycardia episodes recorded from dual chamber defibrillators were divided into two tests. The initial test contained only information from the ventricular electrogram and the second test contained information from both the atrial and ventricular electrograms. For each test, the reviewers were asked to provide the specific diagnosis, the originating chamber of origin of the tachycardia, and the confidence of their responses for each question. McNemar's test for matched pairs was used to determine accuracy and an analysis of variance to determine reviewer confidence. RESULTS: The overall accuracy for both the specific diagnosis (61% vs. 79%; p < 0.001) and the chamber of origin (76% vs. 90%; p < 0.001) improved when both the atrial and ventricular electrograms were available for review. Reviewer confidence appeared to correlate with diagnostic accuracy. CONCLUSIONS: The data clearly show the favorable impact of dual chamber defibrillators on the diagnostic accuracy and confidence of clinicians faced with a clinical tachycardia recorded from an implantable defibrillator. Such improvements may translate into more focused and appropriate therapeutic interventions.

Aged↗
PubMedDate not supplied

Predicting outcome in the idiopathic glomerulopathies.

Improving accuracy in predicting outcome in the idiopathic glomerulopathies requires standard clinical and laboratory data observed over time and the application of certain basic biostatistical tests. In our initial model we examined categories of glomerular disease that progress i.e. membranous, membranoproliferative, diffuse proliferative, focal sclerosing and IgA nephropathy. We determined that a combination of severity and persistence of proteinuria above certain levels over fixed time frames plus the knowledge of any change in glomerular filtration rate during these periods resulted in slopes of creatinine clearances that were the same across this histologic spectrum. This modeling of disease was then applied in a more rigorous fashion to our patients with idiopathic membranous nephropathy (IMGN). Multivariate logistic regression analyses was used to test all other potential clinical and laboratory predictors of chronic renal failure. These additional factors did not improve our ability to predict outcome. This algorithm was subsequently validated on two independent IMGN data bases. Overall accuracy of prediction estimated within 6 months of presentation was maintained at > 85%. The role of this type of evaluation in both clinical practice and research is discussed.

Glomerulonephritis↗
PubMed1994

Customized dual data entry for computerized data analysis.

A major responsibility of any Quality Assurance Unit (QUA) is to ensure data integrity. Errors made during data entry can lead to many problems in the study review process and decrease the quality, accuracy, and overall efficiency of data management. One technique that can reduce the number of data entry errors in computer data sets is the use of a dual entry data system. Currently available software allows creation of customized data entry screens that either closely resemble or duplicate the data collection forms used during studies. Two data entry operators enter data into two independent data sets. The use of an on-screen display that resembles the data collection form reduces the potential for keypunch errors. The two data sets can then be electronically compared. The comparison reports differences between the two data sets. When differences exist, the correct values can be determined by reference to the original data sheets and the two data files can then be corrected. Theoretically, the only key punch errors that will exist after making these corrections are when the two independent entry operators make the same exact data entry error. Typically, the time required for two people to enter data is minimal compared to the time required to manually identify and correct data entry discrepancies. With error-free data entry, we have found that electronic data quality, accuracy, and audit efficiency are improved at every subsequent step of data management, analysis, quality assurance auditing, and report generation.

Information Systems↗
PubMedDate not supplied

A new coincidence model for single particle counters, part III: realization of single particle counting accuracy.

U.S.P. objective tests for particle contamination in injectable fluids are based on counts of single particles in a specified test volume. Accuracy standards for these tests must therefore be based on single particle count accuracy. A definitive analysis for this purpose is described whose results can be used during a counting experiment. To improve the accuracy of particle counter data, U.S.P.XXIII has added a particle counter accuracy requirement defined in terms of a maximum particle concentration for 10 microns particles at which there is a 10% ratio of coincident occurrences. The 10% coincident count ratio cannot be directly measured: it must be calculated from experimental results using a model of the counting process. The U.S.P.XXIII count accuracy specification relies on vendor statements without definition of the methodology or model to be employed. The model of particle counting described in the literature is the Geometric Poisson model due to Jaenicke (4) and extended by Lieberman (5). Recent publications (1, 2) have shown that calculations based on this model do not agree with experimental data. This conclusion is supported and extended in this paper. The single particle counting error estimate for U.S.P.XXIII (788) SVI (3), using Jaenicke's Geometric model to evaluate a good commercial laser sourced detector, is 9.32%; the single particle count error estimate for this detector using the experimentally validated Particle-Triggered Poisson model is 19%. The count error for the concentration calculated with the Jaenicke Geometric model for the same detector is 40.5% when calculated with the validated Particle-Triggered Poisson model. The estimated count error increases for particles larger than 10 microns. Light extinction particle counters are well behaved instruments fully capable of the workhorse task of making accurate, routine single particle contamination measurements in injectable products. In principle, any particle counter instrument now in use, operated within calculated particle size and concentration contours, can deliver accurate single particle counting data. Operation within these limits both within and below the U.S.P.XXIII (788) (3) size range will assure single particle count accuracy without the injection of false counts or undercounts. These count limits vary with particle size and are determined by the capability of the counter. No single particle test can characterize the complex particle size and concentration response of a detector. In practice, selection of a counter with sufficient capability to provide the desired accuracy without constant dilution is an important consideration. When particle concentration exceeds the selected count accuracy contour, dilution and a repeat of the assay provide a practical solution.

Drug Contamination↗
PubMed1999

Prediction of performance on the RCMP physical ability requirement evaluation.

The Royal Canadian Mounted Police use the Physical Ability Requirement Evaluation (PARE) for screening applicants. The purposes of this investigation were to identify those field tests of physical fitness that were associated with PARE performance and determine which most accurately classified successful and unsuccessful PARE performers. The participants were 27 female and 21 male volunteers. Testing included measures of aerobic power, anaerobic power, agility, muscular strength, muscular endurance, and body composition. Multiple regression analysis revealed a three-variable model for males (70-lb bench press, standing long jump, and agility) explaining 79% of the variability in PARE time, whereas a one-variable model (agility) explained 43% of the variability for females. Analysis of the classification accuracy of the males' data was prohibited because 91% of the males passed the PARE. Classification accuracy of the females' data, using logistic regression, produced a two-variable model (agility, 1.5-mile endurance run) with 93% overall classification accuracy.

Adult↗
PubMed2004

The effect of time lapse on the accuracy of two acrylic resins used to assemble an implant framework for soldering.

STATEMENT OF PROBLEM: There are insufficient data on the accuracy of resin indexing materials for the assembly of implant prostheses in vivo. MATERIAL AND METHODS: This in vitro study assessed the fit of an implant framework with the use of 2 common acrylic resins. PURPOSE: A standardized type IV gold alloy cast framework with 3 stainless steel implant replicas secured to 3 premachined gold cylinders placed 200 mm apart using a parallelometer was fabricated on a flat type IV stone model. Wax was placed around the center of each bar section, and a silicone matrix was fabricated to enable the same quantity of material to be used for each assembly. Each bar was sectioned at the center of the matrix, and indices (n=20) were fabricated from Duralay and GC Pattern acrylic resins. The materials were allowed to polymerize for 15 minutes before the assemblies were removed from the model. Frameworks were visually assessed for fit after an additional 15 minutes, after 2 hours, and after 24 hours, using the Sheffield 1-screw test. Observational outcomes are presented indicating visually perceived fit relative to the type of indexing resin. RESULTS: Both indexing materials were judged to be visually accurate at the 15-minute time interval only. CONCLUSION: Within the limitations of this in vitro study, both resin-indexed implant assemblies were judged visually accurate for fit 15 minutes after polymerization but not at subsequent test intervals.

Acrylic Resins↗
PubMed2001

Experimental tests of EEG source localization accuracy in spherical head models.

OBJECTIVES: The locations of electrical sources in the brain can be calculated using EEG data. However, the accuracy of these calculations is not well known because it is usually not possible to compare calculated source locations with actual locations since little accurate location information is available about most sources in the brain. METHODS: In this study, sources at known locations are created by injecting current into electrodes implanted in the brains of human subjects. The locations of the implanted and scalp EEG electrodes are determined from CTs. The EEG signals produced by these dipolar sources are used to calculate source locations in spherical head models containing brain, skull, and scalp layers. The brain and scalp layers have the same electrical conductivity while 3 different skull conductivity ratios of 1/80th, 1/40th, and 1/20th of brain and scalp conductivity are used. Localization errors have been determined for 177 sources in 13 subjects. RESULTS: An average localization error of 10.6 (SD=5.5) mm for all 177 source was obtained for a skull conductivity ratio of 1/40. The average errors for the other ratios are only a few millimeters larger. The average localization error for 108 sources at superior locations in the brain is 9.2 (4.4) mm. The average error for 69 inferior location sources is 12.8 (6.2) mm. There are no significant differences in localization accuracy for deep and superficial sources. CONCLUSIONS: These results indicate that the best average localization that can be achieved using a spherical head model is approximately 10 mm. More realistic head models will be required for greater localization accuracy.

Algorithms↗
PubMed2001

[Clinical laboratory data and reference intervals standardized in Fukuoka].

In Fukuoka whose population is approximately five million inhabitants, surveys on the accuracy of laboratory data have been performed by the Fukuoka Prefecture Medical Association for the last 30 years. We have been attempting to evaluate the data for routine use since 1988, and it has become possible to share laboratory data between all institutions in Fukuoka prefectures. As a result, reference intervals for 23 clinical chemistry analytes were established in 1995, to which were added in 1996 five serum protein constituents that have been utilized for clinical examinations. Methods for documentations and monitorings the data obtained in the prefecture were also established, standardization of the above analytes extended to 97% of the institutions in the prefecture. Results for 14 of the 23 clinical chemistry analytes have become highly reliable and clinically useful as differences between institutions in terms of results have narrowed. Standardization of other analytes is now in progress.

Aged↗
PubMed2000

Predicting marital stability and divorce in newlywed couples.

A longitudinal study with 95 newlywed couples examined the power of the Oral History Interview to predict stable marital relationships and divorce. A principal-components analysis of the interview with the couples (Time 1) identified a latent variable, perceived marital bond, that was significant in predicting which couples would remain married or divorce within the first 5 years of their marriage. A discriminant function analysis of the newlywed oral history data predicted, with 87.4% accuracy, those couples whose marriages remained intact or broke up at the Time 2 data collection point. The oral history data predicted with 81% accuracy those couples who remained married or divorced at the Time 3 data collection point. This study offers support for causal linkages between perceptual biases and selective attention on the path of marriage.

Adult↗
PubMed1999

Virtual light field projection for CT-simulation.

We report a method to project a virtual light field over the patient during CT-simulations of external beam radiotherapy. It can be used to perform all the tasks associated with the physical light field of a conventional simulator. The system consists of a three-dimensional sonic digitizer interfacing with a window-based software on a personal computer. The digitizer can provide the three-dimensional coordinates of any point in space accessible by the digitizer probe. When these coordinates are transformed into the beam's eye view, the position of the digitized point relative to the beam can readily be displayed. Thus, the system establishes a virtual light field in space, which can be "seen" only by the digitizer probe. For any digitized point, the system can immediately show, by the beam's eye view display, whether the point is inside the field, outside of the field, or on the field border. Moreover, this virtual field projection allows one to evaluate external target coverage (or external normal tissue sparing) conveniently and interactively. By simply digitizing the concerned area and viewing its position in the beam's eye view display, one can immediately assess the coverage and if necessary, modify the treatment field accordingly. The system also provides an efficient and essential procedure in CT-simulations for marking treatment portals on the patient. By cruising the digitizer probe on the patient's skin surface under visual and audio guidances, one can promptly find the projection of the field center, field corners, etc., on the patient. Measurements have been performed to study the accuracy of the GP-12 sonic digitizer using rigid phantoms. Based on the measured data, the overall accuracy of the portal localization system is estimated to be +/-2 mm. The system has been in clinical use for our CT simulator.

Calibration↗
PubMed2005

On-line solid phase extraction using the Prospekt-2 coupled with a liquid chromatography/tandem mass spectrometer for the determination of dextromethorphan, dextrorphan and guaifenesin in human plasma.

An on-line liquid chromatography/tandem mass spectrometry (LC-MS/MS) procedure, using the Prospekt- 2 system, was developed and used for the determination of the levels of the active ingredients of cough/cold medications in human plasma matrix. The experimental configuration allows direct plasma injection by performing on- line solid phase extraction (SPE) on small cartridge columns prior to elution of the analyte(s) onto the analytical column and subsequent MS/MS detection. The quantitative analysis of three analytes with differing polarities, dextromethorphan (DEX), dextrorphan (DET) and guaifenesin (GG) in human plasma presented a significant challenge. Using stable-isotope-labeled internal standards for each analyte, the Prospekt-2 on-line methodology was evaluated for sensitivity, suppression, accuracy, precision, linearity, analyst time, analysis time, cost, carryover and ease of use. The lower limit of quantitation for the on-line SPE procedure for DEX, DET and GG was 0.05, 0.05 and 5.0 ng mL(-1), respectively, using a 0.1 mL sample volume. The linear range for DEX and DET was 0.05-50 ng mL(-1) and was 5-5,000 ng mL(-1) for GG. Accuracy and precision data for five different levels of QC samples were collected over three separate days. Accuracy ranged from 90% to 112% for all three analytes, while the precision, as measured by the %RSD, ranged from 1.5% to 16.0%

Antitussive Agents↗
PubMed2002

Aspirin for the primary prevention of cardiovascular events: a summary of the evidence for the U.S. Preventive Services Task Force.

BACKGROUND: The use of aspirin to prevent cardiovascular disease events in patients without a history of cardiovascular disease is controversial. PURPOSE: To examine the benefits and harms of aspirin chemoprevention. DATA SOURCES: MEDLINE (1966 to May 2001). STUDY SELECTION: 1) Randomized trials at least 1 year in duration that examined aspirin chemoprevention in patients without previously known cardiovascular disease and 2) systematic reviews, recent trials, and observational studies that examined rates of hemorrhagic strokes and gastrointestinal bleeding secondary to aspirin use. DATA EXTRACTION: One reviewer read and extracted data from each included article and constructed evidence tables. A second reviewer checked the accuracy of the data extraction. Discrepancies were resolved by consensus. DATA SYNTHESIS: Meta-analysis was performed, and the quantitative results of the review were then used to model the consequences of treating patients with different levels of baseline risk for coronary heart disease. Five trials examined the effect of aspirin on cardiovascular events in patients with no previous cardiovascular disease. For patients similar to those enrolled in the trials, aspirin reduces the risk for the combined end point of nonfatal myocardial infarction and fatal coronary heart disease (summary odds ratio, 0.72 [95% CI, 0.60 to 0.87]). Aspirin increased the risk for hemorrhagic strokes (summary odds ratio, 1.4 [CI, 0.9 to 2.0]) and major gastrointestinal bleeding (summary odds ratio, 1.7 [CI, 1.4 to 2.1]). All-cause mortality (summary odds ratio, 0.93 [CI, 0.84 to 1.02]) was not significantly affected. For 1000 patients with a 5% risk for coronary heart disease events over 5 years, aspirin would prevent 6 to 20 myocardial infarctions but would cause 0 to 2 hemorrhagic strokes and 2 to 4 major gastrointestinal bleeding events. For patients with a risk of 1% over 5 years, aspirin would prevent 1 to 4 myocardial infarctions but would cause 0 to 2 hemorrhagic strokes and 2 to 4 major gastrointestinal bleeding events. CONCLUSIONS: The net benefit of aspirin increases with increasing cardiovascular risk. In the decision to use aspirin chemoprevention, the patient's cardiovascular risk and relative utility for the different clinical outcomes prevented or caused by aspirin use must be considered.

Adult↗
PubMed2004

Does this woman have osteoporosis?

CONTEXT: Although recent US Preventive Services Task Force guidelines recommend bone densitometry for all women older than 65 years, identifying younger women at increased risk for osteoporosis and women with occult vertebral fractures remains a clinical challenge. We investigated whether physical signs are useful as a screening tool either for early referral to bone densitometry or for occult spinal fractures. OBJECTIVE: To review the accuracy and precision of physical examination findings for the diagnosis of osteopenia, osteoporosis, or spinal fracture. DATA SOURCES: We conducted a MEDLINE search for articles published from 1966 through August 2004, manually reviewed bibliographies, consulted 4 clinical skills textbooks, and contacted experts in the field. STUDY SELECTION: Studies were included if they contained adequate original data on the accuracy or precision of physical examination for diagnosing osteopenia, osteoporosis, or spinal fracture. Two authors screened abstracts found by the search. Fourteen of 191 full articles reviewed met inclusion criteria. DATA EXTRACTION: Two authors independently abstracted data from the included studies. Disagreements were resolved by discussion. DATA SYNTHESIS: No single maneuver is sufficient to rule in or rule out osteoporosis or spinal fracture without further testing. The following yielded the greatest positive likelihood ratios (LR+): weight less than 51 kg, LR+, 7.3 (95% confidence interval [CI], 5.0-10.8); tooth count less than 20, LR+, 3.4 (95% CI, 1.4-8.0); rib-pelvis distance less than 2 finger breadths, LR+, 3.8 (95% CI, 2.9-5.1); wall-occiput distance greater than 0 cm, LR+, 4.6 (95% CI, 2.9-7.3), and self-reported humped back, LR+, 3.0 (95% CI, 2.2-4.1). CONCLUSIONS: In patients who do not meet current bone mineral density screening recommendations, several convenient examination maneuvers, especially low weight, can significantly change the pretest probability of osteoporosis and suggest the need for earlier screening. Wall-occiput distance greater than 0 cm and rib-pelvis distance less than 2 fingerbreadths suggest the presence of occult spinal fracture.

Absorptiometry, Photon↗
PubMed2001

Potential technology for studying dosimetry and response to airborne chemical and biological pollutants.

Advances in computational, and imaging techniques have enabled the rapid development of three-dimensional (3-D) models of biological systems in unprecedented detail. Using these advances, 3-D models of the lungs and nasal passages of the rat and human are being developed to ultimately improve predictions of airborne pollutant dosimetry. Techniques for imaging the respiratory tract by magnetic resonance imaging (MRI) were developed to improve the speed and accuracy of geometric data collection for mesh reconstruction. The MRI resolution is comparable to that obtained by manual measurements but at much greater speed and accuracy. Newly developed software (NWGrid) was utilized to translate imaging data from MR into 3-D mesh structures. Together, these approaches significantly reduced the time to develop a 3-D model. This more robust airway structure will ultimately facilitate modeling gas or vapor exchange between the respiratory tract and vasculature as well as enable linkages of dosimetry with cell response models. The 3-D, finite volume, viscoelastic mesh structures form the geometric basis for computational fluid dynamics modeling of inhalation, exhalation and the delivery of individual particles (or concentrations of gas or vapors) to discrete regions of the respiratory tract. The ability of these 3-D models to resolve dosimetry at such a high level of detail will require new techniques to measure regional airflows and particulate deposition for model validation.

Air Movements↗
PubMedDate not supplied

Does this woman have an acute uncomplicated urinary tract infection?

CONTEXT: Symptoms suggestive of acute urinary tract infection (UTI) constitute one of the most common reasons for women to visit clinicians. Although the clinical encounter typically involves taking a history and performing a physical examination, the diagnostic accuracy of the clinical assessment for UTI remains uncertain. OBJECTIVE: To review the accuracy and precision of history taking and physical examination for the diagnosis of UTI in women. DATA SOURCES: We conducted a MEDLINE search for articles published from 1966 through September 2001 and manually reviewed bibliographies, 3 commonly used clinical skills textbooks, and contacted experts in the field. STUDY SELECTION: Studies were included if they contained original data on the accuracy or precision of history or physical examination for diagnosing acute uncomplicated UTI in women. One author initially screened titles and abstracts found by our search. Nine of 464 identified studies met inclusion criteria. DATA EXTRACTION: Two authors independently abstracted data from the included studies. Disagreements were resolved by discussion and consensus with a third author. DATA SYNTHESIS: Four symptoms and 1 sign significantly increased the probability of UTI: dysuria (summary positive likelihood ratio [LR], 1.5; 95% confidence interval [CI], 1.2-2.0), frequency (LR, 1.8; 95% CI, 1.1-3.0), hematuria (LR, 2.0; 95% CI, 1.3-2.9), back pain (LR, 1.6; 95% CI, 1.2-2.1), and costovertebral angle tenderness (LR, 1.7; 95% CI, 1.1-2.5). Four symptoms and 1 sign significantly decreased the probability of UTI: absence of dysuria (summary negative LR, 0.5; 95% CI, 0.3-0.7), absence of back pain (LR, 0.8; 95% CI, 0.7-0.9), history of vaginal discharge (LR, 0.3; 95% CI, 0.1-0.9), history of vaginal irritation (LR, 0.2; 95% CI, 0.1-0.9), and vaginal discharge on examination (LR, 0.7; 95% CI, 0.5-0.9). Of all individual diagnostic signs and symptoms, the 2 most powerful were history of vaginal discharge and history of vaginal irritation, which significantly decreased the likelihood of UTI when present (LRs, 0.3 and 0.2, respectively). One study examined combinations of symptoms, and the resulting LRs were more powerful (24.6 for the combination of dysuria and frequency but no vaginal discharge or irritation). One study of patients with recurrent UTI found that self-diagnosis significantly increased the probability of UTI (LR, 4.0). CONCLUSIONS: In women who present with 1 or more symptoms of UTI, the probability of infection is approximately 50%. Specific combinations of symptoms (eg, dysuria and frequency without vaginal discharge or irritation) raise the probability of UTI to more than 90%, effectively ruling in the diagnosis based on history alone. In contrast, history taking, physical examination, and dipstick urinalysis are not able to reliably lower the posttest probability of disease to a level where a UTI can be ruled out when a patient presents with 1 or more symptoms.

Acute Disease↗
PubMed2005

Surgeons' perspectives on surgical wound infection rate data in Queensland, Australia.

BACKGROUND: The results of the Study on the Efficacy of Nosocomial Infection Control (SENIC) project demonstrated that hospitals with active infection control programs had lower rates of nosocomial infection than those without such programs. A key component of these programs was the inclusion of a systematic method for monitoring nosocomial infection and reporting these infections to clinicians. OBJECTIVES: To identify the perspectives of surgeons in Queensland, Australia, regarding infection rate data in terms of its accuracy and usefulness as well as their perceptions regarding acceptable infection rates for surgical procedures classified as "clean" or "contaminated." METHODS: A postal survey was conducted, with a convenience sample of 510 surgeons. RESULTS: More than 40% (n = 88) of respondents believed that the acceptable infection rate associated with clean surgical procedures should be less than 1%, a rate much lower than the threshold of 1.4% to 4.1% set by the Australian Council on Healthcare Standards (ACHS). Almost 30% (n = 55) of respondents reported that they would accept infection rates of 10% or higher for contaminated surgical procedures, which is higher than the ACHS threshold of 1.4% to 7.9%. Respondents identified failure to include postdischarge infections in the data and difficulties standardizing criteria for diagnosis of infection as the major impediments to the accuracy and usefulness of data provided. CONCLUSION: The results of this study have significant implications in relation to the preparation of surgical site infection reports, especially in relation to the inclusion of postdischarge surveillance data and information regarding pathogens, antibiotic sensitivities, and comorbidities of patients developing surgical site infection. Surgeons also identified the need to include information regarding the use of standardized definitions in the diagnosis of wound infection and parameters that allow comparison of infection rates to improve their perceptions regarding data accuracy and usefulness.

Attitude of Health Personnel↗