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PubMedDate not supplied

[Magnetic resonance in the evaluation of mediastinal masses].

Thirty-three patients with mediastinal masses were examined by means of MRI to obtain elements for lesion characterization, to evaluate lesion extent, and to assess the relationship of the mass to the surrounding structures, especially the great vessels (accuracy: 84.84%), mediastinal structures (accuracy: 76.78%), and lung parenchyma (accuracy 69.69%). MR data were compared to CT findings; sensitivity, specificity and accuracy were subsequently compared to surgical and histologic findings. The results have shown MRI to be a very reliable method in the evaluation of mediastinal masses.

False Negative Reactions↗
PubMed2002

Solitary pulmonary nodules: accuracy and cost-effectiveness of sodium iodide FDG-PET using Australian data.

This study uses Australian data to confirm the accuracy of dedicated sodium iodide (NaI) fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) in evaluating indeterminate solitary pulmonary nodules (SPNs) and to determine the conditions under which PET could play a cost-effective role in this evaluation. Ninety-two patients from two Australian hospitals in different states underwent FDG-PET for evaluation of an SPN. Observed values for prior probability of malignancy and diagnostic accuracy of PET were applied to previously published decision tree models using published Australian health care costs. The accuracy of FDG-PET was 93% with a sensitivity of 92% and a specificity of 95%. The prior probability of malignancy (0.54), PET sensitivity and PET specificity indicated cost savings per patient of up to EUR 455 (Adollars 774) based on a PET cost of EUR 706 (Adollars 1,200). PET would remain cost-effective for levels of prior probability up to 0.8-0.9 and a PET cost of EUR 736-1,161 (Adollars 1,252-Adollars 1,974). It is concluded that NaI PET is accurate, cost saving and cost-effective for the characterisation of indeterminate pulmonary nodules in Australia. Comparison with previous reports from the United States confirms that FDG-PET can remain cost-effective despite population differences in medical costs, disease prevalence and PET diagnostic performance.

Aged↗
PubMed1998

Spatial perception of speech in various signal to noise ratios.

OBJECTIVE: The study was designed to assess the effects of background noise level on the detection and localization of speech. DESIGN: The phrase "Where is this?" was presented either in quiet or in a diffuse noise field, through loudspeakers arranged in a 360 degrees azimuth array. The noise conditions included 11 signal to noise ratios (SNRs) ranging from -18 dB SNR to +12 dB SNR in 3 dB increments. Seventeen normal-hearing subjects, aged 18 to 29, participated in the study. RESULTS: Results revealed that in all listening conditions the signal was most easily detected when presented through a loudspeaker positioned at 90 degrees or 270 degrees azimuth. Although the actual level for 50% detection varied as a function of loudspeaker location and SNR, 85% and 100% of all presentations of the signal were detected at -9 dB and -6 dB SNR, respectively. Localization accuracy improved as the SNR increased, ranging from 18% accuracy at -18 dB SNR to 89% at +12 dB SNR. Localization accuracy in quiet was 95%. The data are discussed in reference to patterns of responses at each loudspeaker location. CONCLUSIONS: Detection of the target signal deteriorated as background noise level increased and was dependent on the source location of the incoming signal, as expected. Localization accuracy of the target signal was highly dependent on the SNR and spatial location of the signal source. Detection and localization accuracy data were found to be repeatable across test sessions and response patterns were found to be symmetrical on the right and left sides of the horizontal plane.

Adolescent↗
PubMed2001

Accuracy of administrative and trauma registry databases.

OBJECTIVE: Accurate data are needed to evaluate clinical outcomes, therapeutic modalities, and quality of care in trauma. Administrative data, usually used for billing, and trauma registries, have been used to perform these functions. This study compares data for trauma patients from administrative and trauma registry databases at a Level I trauma center. METHODS: Data from patients injured in 1998 were obtained from both the trauma registry and administrative database. These International Classification of Diseases, Ninth Revision, Clinical Modification codes signify an admitting diagnosis of trauma. Patients from each database were "matched" by admission date, medical record number, age, and name. The two matched data sets were compared for accuracy in recording data. Chi-square analysis was used to compare groups. RESULTS: There were 2,702 patients found in both databases. One hundred eighteen patients with significant trauma were recorded in the trauma registry, but not in the administrative database. Comparison of recorded data for "matched" patients is as follows. The underreporting of mechanism of injury, diagnoses, diagnostic interventions, surgical procedures, and complications was rampant throughout the administrative database. Statistical significance was seen in the comparison between the trauma registry and the administrative database with motor vehicle collisions (458 vs. 391), abdominal injuries (346 vs. 293), orthopedic injuries (1,243 vs. 1,101), and thoracic injuries (486 vs. 397). Diagnostic interventions such as diagnostic peritoneal lavage, head computed tomographic scans, and abdominal computed tomographic scans were all grossly underrecorded, with only 40%, 12%, and 9% captured by the administrative database, respectively. Analysis of surgical procedures revealed these same trends, with statistical significance seen in abdominal and orthopedic procedures. Complications such as acute respiratory distress syndrome and deep venous thrombosis showed statistically significant differences. Mortality was underreported in the administrative database, with 14 deaths omitted. CONCLUSION: This study shows that administrative data have copious omissions of specific injuries, diagnostic and therapeutic interventions, as well as complications. The trauma registry recorded more of the diagnoses, diagnostics, procedures, and outcomes in the care of trauma patients. Trauma registries may be more useful than administrative databases in assessing quality of care and diagnostic and therapeutic interventions.

Adult↗
PubMedDate not supplied

Computerized blood pressure and heart rate recording system interfaces standard chart recorder with any micro-computer.

The designed inexpensive blood pressure recording system (BPRS) gives any microcomputer direct on-line blood pressure and heart rate recording capability that will save research time and increase the accuracy of collected data. The data is automatically stored in a file compatible with most graphic and statistical processing software. In vitro testing, over a range of 0-200 mmHg and 0-360 beats per minute showed a 0.999 intraclass correlation. In vivo testing of the BPRS used anaesthetized rats whereby their systolic and diastolic pressures were measured simultaneously with heart rate. The blood pressures and heart rate data, measured by the BPRS demonstrated excellent stability, sensitivity and accuracy when compared to those measured by standard pressure transducers in conjunction with a Grass polygraph and a sphygmomanometer.

Animals↗
PubMed2004

Identification and recall of children with chronic medical conditions for influenza vaccination.

OBJECTIVES: Despite long-standing recommendations to provide annual influenza vaccination to children with chronic medical conditions, immunization rates are <10% in most primary care settings. Many obstacles impede implementation of these recommendations, including the challenge of identifying targeted children and the need to immunize yearly in a short time interval. The objective of this study was to assess the accuracy of billing data for identifying children who have high-risk conditions (HRCs) and need influenza vaccination and 2) to evaluate the efficacy of reminder/recall for children with HRCs. METHODS: The study was conducted in 4 private pediatric practices in metropolitan Denver, Colorado, that share a computerized billing system and also participate in an immunization registry. For all children aged 6 to 72 months, registry records were linked with the billing database. Patients with >or=1 encounters for an HRC in the previous 24 months were selected, with HRCs identified from International Classification of Diseases, Ninth Revision, Clinical Modification diagnostic codes. Using medical records as the "gold standard," we reviewed 327 randomly selected records to determine the sensitivity, specificity, and accuracy of billing data for identifying HRCs. For children with an HRC, we then conducted a randomized, controlled trial of reminder/recall for influenza vaccination. The primary outcome of the recall trial was receipt of influenza vaccine. RESULTS: Billing data had a sensitivity of 72% (95% confidence interval [CI]: 48%-95%), specificity of 95% (95% CI: 90%-100%), and overall accuracy of 90% (95% CI: 84%-96%) in determining which children had an HRC. Of the 17,273 patients aged 6 to 72 months, 2007 had >or=1 HRCs (12% overall; range: 9%-14% per practice). Asthma/reactive airways disease accounted for 87% of all HRCs. Reminder/recall significantly increased influenza immunization in children with HRCs, with a vaccination rate of 42% in those recalled, compared with 25% in control subjects. Recalled subjects were more likely to have an office visit (68% vs 60%) and less likely to have a missed opportunity to immunize (28% vs 37%) compared with control subjects. CONCLUSIONS: Diagnosis-based billing data accurately identified children who had HRCs and needed annual influenza vaccination, and registry-driven reminder/recall significantly increased influenza immunization in targeted children.

Child↗
PubMed1992

A method for the independent assessment of the accuracy of hematology whole-blood calibrators.

An independent assessment of the accuracy with which a large manufacturer assigned values to hematologic calibrators was performed. Data were collected from 1,767 hospitals and clinics distributed over North America. Statistical analysis of the mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration of these patient data confirmed the accuracy of the values for hemoglobin, erythrocyte count, hematocrit, and erythrocyte indices for the calibrators manufactured and released during a 9-month period. This approach proved both workable and effective in detecting inaccuracies of less than 1%. Few technologist-users have the time or the equipment to verify independently the accuracy of hematologic calibrators. The manufacturers should perform ongoing, independent assessments of the accuracy of their products. The statistical analysis of patient data provides manufacturers with a suitable method.

Calibration↗
PubMed2005

Accuracy of ultrasound biometry in the prediction of macrosomia: a systematic quantitative review.

OBJECTIVE: To determine the accuracy of ultrasonographically estimated fetal weight (EFW) and abdominal circumference (AC) in the prediction of macrosomia. DESIGN: Systematic quantitative review. METHODS: Studies were identified without language restrictions from MEDLINE (1966-2003), EMBASE (1980-2003), Cochrane Library (2003:4), SCISEARCH (1974-2003) and manual searching of bibliographies of known primary and review articles. Studies were selected if accuracy of ultrasonographically EFW or AC was evaluated for predicting macrosomia using birthweight as the reference standard. Data were extracted on study characteristics, quality and accuracy. Data were pooled to produce summary receiver operating characteristic curves (sROC) for studies with various test thresholds. Summary likelihood ratios for positive (LR+) and negative (LR-) test results were generated for an EFW of 4000 g and an AC of 36 cm for predicting birthweight of over 4000 g. MAIN OUTCOME MEASURES: Birthweight over various thresholds. RESULTS: There were 36 primary articles consisting of 63 accuracy studies (51 evaluating the accuracy of EFW, and 12 accuracy of fetal AC), including a total of 19,117 women. The sROC area for EFW was not different from the area for fetal AC (0.87 vs 0.85, P= 0.91). For predicting a birthweight of over 4000 g, the summary LRs were 5.7 (95% CI: 4.3 to 7.6) for a positive test and 0.48 (95% CI: 0.38 to 0.60) for a negative test, using Hadlock's method of ultrasonographically estimating fetal weight. For ultrasound fetal AC of 36 cm, the respective LRs for predicting a birthweight over 4000 g were 6.9 (95% CI: 5.2 to 9.0) and 0.37 (0.30-0.45). CONCLUSION: There is no difference in accuracy between ultrasonographically EFW and AC in the prediction of a macrosomic baby at birth. A positive test result is more accurate for ruling in macrosomia than a negative test result for ruling it out.

Abdomen↗
PubMed1998

Prediction of protein hydration sites from sequence by modular neural networks.

The hydration properties of a protein are important determinants of its structure and function. Here, modular neural networks are employed to predict ordered hydration sites using protein sequence information. First, secondary structure and solvent accessibility are predicted from sequence with two separate neural networks. These predictions are used as input together with protein sequences for networks predicting hydration of residues, backbone atoms and sidechains. These networks are trained with protein crystal structures. The prediction of hydration is improved by adding information on secondary structure and solvent accessibility and, using actual values of these properties, residue hydration can be predicted to 77% accuracy with a Matthews coefficient of 0.43. However, predicted property data with an accuracy of 60-70% result in less than half the improvement in predictive performance observed using the actual values. The inclusion of property information allows a smaller sequence window to be used in the networks to predict hydration. It has a greater impact on the accuracy of hydration site prediction for backbone atoms than for sidechains and for non-polar than polar residues. The networks provide insight into the mutual interdependencies between the location of ordered water sites and the structural and chemical characteristics of the protein residues.

Amino Acid Sequence↗
PubMed2004

Hospital chart review provided more accurate comorbidity information than data from a general practitioner survey or an administrative database.

BACKGROUND AND OBJECTIVE: The accuracy of comorbidity data within the Western Australian Data Linkage System was evaluated by means of comparison with hospital charts and a general practitioner (GP) survey. METHODS: Patients (n=2,037) with a hospital admission from 1991 to 1996 were selected. Linked data were extracted for 100 comorbidities, categorized into 16 diagnostic chapters, for each hospital admission within a 5-year period. Clinical chart review and a GP survey were performed. Comorbidity occurrence in each data source and false-positive and false-negative diagnoses were ascertained. RESULTS: Administrative data contained 45.5% of comorbidity recorded in hospital charts and underascertained secondary conditions for all 16 diagnostic chapters. False-positive diagnoses were low for most conditions (range: 0-1.5%); however, a high occurrence of false negatives existed for all comorbidity chapters (range: 16.3-91.3%). GP-identified comorbidity was 20.0% greater than that found using administrative data but, with the exceptions of injury-poisoning and cutaneous-subcutaneous diseases, was less (42.0%) than that observed from hospital charts. CONCLUSION: Our results indicate that when accurate comorbidity data are crucial to health outcome research, hospital chart review (as opposed to using administrative data) may be required. Furthermore, surveying GPs, at least in Australia, appears an unsatisfactory alternative to hospital charts for obtaining retrospective comorbidity information.

Comorbidity↗
PubMed1999

The use of automated data to identify complications and comorbidities of diabetes: a validation study.

We evaluated the accuracy of administrative data for identifying complications and comorbidities of diabetes using International Classification of Diseases, 9th edition, Clinical Modification and Current Procedural Terminology codes. The records of 471 randomly selected diabetic patients were reviewed for complications from January 1, 1993 to December 31, 1995; chart data served to validate automated data. The complications with the highest sensitivity determined by a diagnosis in the medical records identified within +/-60 days of the database date were myocardial infarction (95.2%); amputation (94.4%); ischemic heart disease (90.3%); stroke (91.2%); osteomyelitis (79.2%); and retinal detachment, vitreous hemorrhage, and vitrectomy (73.5%). With the exception of amputation (82.9%), positive predictive value was low when based on a diagnosis identified within +/-60 days of the database date but increased with relaxation of the time constraints to include confirmation of the condition at any time during 1993-1995: ulcers (88.5%); amputation (85.4%); and retinal detachment, vitreous hemorrhage and vitrectomy (79.8%). Automated data are useful for ascertaining potential cases of some diabetic complications but require confirmatory evidence when they are to be used for research purposes.

Adolescent↗
PubMed1998

A data reduction scheme for improving the accuracy of oxygen saturation calculations from spectrometric in vivo measurements.

A developing tool in ophthalmological research and practice is the study of the oxygen saturation in retinal vessels because this measurement contains important diagnostic information about the metabolism at the human ocular fundus. Imaging spectrometry enables locally resolved measurements of the oxygen saturation simultaneously in arteries and veins. The vessel reflex, imaging errors of the detection system and the noise of the signal result in substantial uncertainties in the calculated data. We present a data processing method for the improvement of the primary information leading to a reduction of the uncertainties of the derived oxygen saturation.

Biometry↗
PubMed2000

An objective analysis of the pressure-volume curve in the acute respiratory distress syndrome.

To assess the interobserver and intraobserver variability in the clinical evaluation of the quasi-static pressure-volume (P-V) curve, we analyzed 24 sets of inflation and deflation P-V curves obtained from patients with ARDS. We used a recently described sigmoidal equation to curve-fit the P-V data sets and objectively define the point of maximum compliance increase of the inflation limb (P(mci, i)) and the true inflection point of the deflation limb (P(inf,d)). These points were compared with graphic determinations of lower Pflex by seven clinicians. The graphic and curve-fitting methods were also compared for their ability to reproduce the same parameter value in data sets with reduced number of data points. The sigmoidal equation fit the P-V data with great accuracy (R(2) = 0.9992). The average of Pflex determinations was found to be correlated with P(mci,i) (R = 0.89) and P(inf,d) (R = 0.76). Individual determinations of Pflex were less correlated with the corresponding objective parameters (R = 0.67 and 0.62, respectively). Pflex + 2 cm H(2)O was a more accurate estimator of P(inf,d) (2 SD = +/-6.05 cm H(2)O) than Pflex was of P(mci,i) (2 SD = +/-8.02 cm H(2)O). There was significant interobserver variability in Pflex, with a maximum difference of 11 cm H(2)O for the same patient (SD = 1.9 cm H(2)O). Clinicians had difficulty reproducing Pflex in smaller data sets with differences as great as 17 cm H(2)O (SD = 2.8 cm H(2)O). In contrast, the curve-fitting method reproduced P(mci,i) with great accuracy in reduced data sets (maximum difference of 1.5 cm H(2)O and SD = 0.3 cm H(2)O). We conclude that Pflex rarely coincided with the point of maximum compliance increase defined by a sigmoid curve-fit with large differences in Pflex seen both among and within observers. Calculating objective parameters such as P(mci,i) or P(inf,d) from curve-fitted P-V data can minimize this large variability.

Adult↗
PubMed2004

Development and validation of a reversed-phase liquid chromatographic method for analysis of degradation products of estradiol in Vagifem tablets.

A stability-indicating liquid chromatographic method for the determination of degradation products and impurities in Vagifem, estradiol vaginal tablets has been developed and validated. Vagifem is a low dose preparation containing only 25microg 17beta-estradiol in a tablet matrix of 80mg (a drug to excipient ratio of 1:3200). This paper presents the rationale for the optimization of the sample preparation in order to minimize placebo interference as well as validation data for linearity, accuracy, precision, ruggedness, specificity and limits of detection and quantification. Data shows that the method is suitable for routine analysis of minute amounts of estradiol impurities.

Chromatography, High Pressure Liquid↗
PubMed1995

Organic acids in hydrothermal solutions: standard molal thermodynamic properties of carboxylic acids and estimates of dissociation constants at high temperatures and pressures.

Experimental standard partial molal volumes, heat capacities, and entropies as well as apparent standard partial molal enthalpies and Gibbs free energies of mono- and dicarboxylic acids and their anions at low temperatures and pressures are used to generate correlations for predicting the same properties at high temperatures and pressures for 59 carboxylic and 18 hydroxyacid species with the revised Helgeson-Kirkham-Flowers (HKF) equation of state. Predicted equilibrium dissociation constants are compared with experimental values from the literature and tabulated as functions of pressure and temperature for 25 carboxylic acids and nine hydroxyacids. Close agreement between independent predictions and experimental data supports the generality of the computational techniques and the accuracy of predicted data. These results allow incorporation of a wide variety of organic acids into quantitative interpretations of geochemical processes.

Anions↗
PubMed2005

Are structured data structured identically? Investigating the uniformity of pediatric patient data recorded using OpenSDE.

OBJECTIVE: OpenSDE is an application that supports structured recording of narrative patient data to enable use of the data in both clinical practice and clinical research. Reliability and accuracy of collected data are essential for subsequent data use. In this study we analyze the uniformity of data entered with OpenSDE. Our objective is to obtain insight into the consensus and differences of recorded data. METHODS: Three pediatricians transcribed 20 paper patient records using OpenSDE. The transcribed records were compared and all recorded findings were classified into one of six categories of difference. RESULTS: Of all findings 22% were recorded identically; 17% of the findings were recorded differently (predominantly as free text); 61% was omitted, inferred, or in conflict with the paper record. CONCLUSION: The results of this study show that recording patient data using structured data entry does not necessarily lead to uniformly structured data.

Humans↗
PubMed1995

Assessment of the completeness and accuracy of computer medical records in four practices committed to recording data on computer.

BACKGROUND: General practice computer databases are being increasingly seen as a source of data for public health monitoring and commissioning. Such ambitions depend on routine clinical data being recorded with acceptable completeness and accuracy. AIM: The aim of this study was to assess the completeness and accuracy of the computer medical records in four high-recording general practices. METHOD: Four general practices in the Trent Region that use the EMIS computer system, and were known to be high recorders of clinical data on their computer databases, were selected. A retrospective analysis of the computer records, a prospective comparison of a sample of computer records with manual records, and a prospective comparison between videorecorded consultations and their manual and computer records were undertaken. RESULTS: Checks for completeness in computer recording of diabetes mellitus and glaucoma showed high levels of accurate recording, 97% and 92% respectively. Prevalence rates between practices were reasonably comparable. No practice consistently, across 10 diagnoses, recorded prevalences higher or lower than the other practices; those diagnoses with recognized objective diagnostic criteria were recorded with a more consistent prevalence than those without. Lifestyle data recording was low; overall, smoking habits and alcohol consumption were recorded for 52% and 38% of patients aged over 16 years, respectively. Comparison of the manual records with the computer records showed that the computer records were sufficiently complete with regard to diagnoses (82% of all items recorded), prescriptions (100%) and referrals (67%), but missed most of the remaining data that a manual record captured. The videorecorded validation study showed that there were no important lapses in the recording of diagnoses, prescriptions or referrals when the computer recording was compared to the actual process of the consultations. CONCLUSION: In these four high-recording practices the data in computer records were of sufficient completeness and accuracy to allow meaningful data aggregation for some diagnoses, prescriptions and referrals. Standardized protocols for defining which patients are included and excluded from major disease groups are required.

England↗
PubMed1998

How well do birth certificates describe the pregnancies they report? The Washington State experience with low-risk pregnancies.

OBJECTIVES: Birth certificates are a major source of population-based data on maternal and perinatal health, but their value depends on the accuracy of the data. This study assesses the validity of information recorded on the birth certificates for women in Washington State who were considered to be low risk at entry into care. METHODS: Birth certificates were matched to data abstracted from prenatal and intrapartum clinic and hospital records of a sample of 1937 Washington State obstetrical patients who were considered to be low risk at the beginning of their pregnancies. Accuracy of a variety of pregnancy characteristics (e.g., complications, procedures) on the birth certificate was analyzed using percentage agreement and sensitivity with record abstracts as the "gold standard." Next, we weighted the data from each source to produce estimates of pregnancy characteristics in the population. We compared these estimates from the two data sources to see whether they provide similar pictures of this subpopulation. RESULTS: Missing data for specific items on the birth certificates ranged from 0% to 24%. The birth certificate accurately captured gravidity and parity, but was less likely to report prenatal and intrapartum complications. The population estimates of the two data sources were significantly different. CONCLUSIONS: Because birth certificates significantly underestimated the complications of pregnancies, number of interventions, number of procedures, and prenatal visits, use of these data for health policy development or resource allocation should be tempered with caution.

Adult↗