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PubMed1997

[Reliability and accuracy of reported causes of death from cancer. II. Accuracy of stomach cancer reported in the municipality of Rio de Janeiro County, Brazil]

Quality of data is a central concern in epidemiological studies, particularly when using secondary data. This study aims to carry out on reliability and accuracy of stomach cancer mortality data in the city of Rio de Janeiro. A simple random sample of 97 death certificates was obtained from a total of 645 stomach cancer deaths in 1990, and was used for validation. A questionnaire specifically designed to obtain clinical and laboratory data was completed for each case. Two physicians read this questionnaire and completed the new death certificates, allowing analysis of the instrument's reliability. A total of 86 cases were studied as a consequence of 11 losses (11.3%). Reliability analysis of questionnaires revealed 90.7% agreement according to stomach cancer diagnosis (kappa = 0.73). Accuracy was calculated by positive predictive value: 90.7%. Eight cases were discharged after clinical and laboratory revision. The study concludes that mortality data by stomach cancer in the city of Rio de Janeiro are very reliable, and that their level of accuracy is adequate for use in epidemiological studies.

Journal Article↗
PubMed1990

Accuracy of complete dental arch impressions and stone casts using a three-dimensional measurement system. Effects on accuracy of rubber impression materials and trays.

The purpose of this study was to investigate and compare the accuracy of complete dental arch impressions and stone casts made with two kinds of impression materials (addition-type silicone and polysulfide rubber) and trays (custom tray and modified custom tray). In addition, the effect of the quantity of stone was examined. Impressions were made from a metallic model of a simplified maxillary dentition. Impressions and stone casts were measured respectively with a three-dimensional measuring microscope. The results were as follows: 1. Distortions of impressions were so small that the reproducibilities of impressions were superior three-dimensionally. These kinds of impressions and trays did not influence the accuracy of impressions. 2. The setting expansion of the stone in the impression occurred in the outward direction and was affected by the kinds of impressions and trays. 3. The arch widths and lengths of the stone casts tended to increase in number. 4. Stone casts made with addition-type silicone impression material and a custom tray were the most accurate because the combination of the impression material and tray effectively suppressed the setting expansion of stone. 5. The accuracy of stone casts could be improved by controlling the quantity of stone.

Calcium Sulfate↗
PubMed2003

[Reporting studies of diagnostic accuracy according to a standard method; the Standards for Reporting of Diagnostic Accuracy (STARD)].

The objective of the 'Standards for Reporting of Diagnostic Accuracy' (STARD) initiative is to improve the reporting of studies of diagnostic accuracy, so as to allow readers to assess the potential for bias in a study and to evaluate the generalibility of its results. The group searched the literature to identify publications on the appropriate conduct and reporting of diagnostic studies. This was used to draw up a list of potential items. During a consensus meeting, a group of researchers, medical journal editors, and members of professional organisations reduced this list to a usable checklist. Wherever possible, evidence from the literature was used to justify the decisions made. The search for published guidelines about diagnostic research yielded 33 previously published checklists, from which a list of 75 potential items was extracted. At the consensus meeting, participants shortened the list to a 25-item checklist. A generic flow diagram was drawn up to provide guidance on the method for including patients, the order in which tests were to be conducted and the number of patients to undergo the test being evaluated, the reference standard, or both. A scientific publication can only be assessed when the reporting is both correct and complete. Use of the checklist and flow diagram will improve the quality of reports produced, to the advantage of clinicians, researchers, reviewers, journal editors and other interested parties.

Algorithms↗
PubMed2006

Accuracy of B-type natriuretic peptide tests to exclude congestive heart failure: systematic review of test accuracy studies.

BACKGROUND: Congestive heart failure (CHF) is a major public health problem. The use of B-type natriuretic peptide (BNP) tests shows promising diagnostic accuracy. Herein, we summarize the evidence on the accuracy of BNP tests in the diagnosis of CHF and compare the performance of rapid enzyme-linked immunosorbent assay (ELISA) and standard radioimmunosorbent assay (RIA) tests. METHODS: We searched electronic databases and the reference lists of included studies, and we contacted experts. Data were extracted on the study population, the type of test used, and methods. Receiver operating characteristic (ROC) plots and summary ROC curves were produced and negative likelihood ratios pooled. Random-effect meta-analysis and metaregression were used to combine data and explore sources of between-study heterogeneity. RESULTS: Nineteen studies describing 22 patient populations (9 ELISA and 13 RIA) and 9093 patients were included. The diagnosis of CHF was verified by echocardiography, radionuclide scan, or echocardiography combined with clinical criteria. The pooled negative likelihood ratio overall from random-effect meta-analysis was 0.18 (95% confidence interval [CI], 0.13-0.23). It was lower for the ELISA test (0.12; 95% CI, 0.09-0.16) than for the RIA test (0.23; 95% CI, 0.16-0.32). For a pretest probability of 20%, which is typical for patients with suspected CHF in primary care, a negative result of the ELISA test would produce a posttest probability of 2.9%; a negative RIA test, a posttest probability of 5.4%. CONCLUSIONS: The use of BNP tests to rule out CHF in primary care settings could reduce demand for echocardiography. The advantages of rapid ELISA tests need to be balanced against their higher cost.

Biomarkers↗
PubMed1983

Evolutionary aspects of accuracy of phenylalanyl-tRNA synthetase. Accuracy of fungal and animal mitochondrial enzymes and their relationship to their cytoplasmic counterparts and a prokaryotic enzyme.

Phenylalanyl-tRNA synthetases from mitochondria of yeast and hen liver resemble their corresponding cytoplasmic counterparts. Whereas slight intraspecies differences at the amino acid binding site, reflecting variations in the structures of these distinct enzymes, are exploitable by phenylalanine analogues, no intraspecies difference can be noted for the strategies to achieve the high fidelity of protein synthesis. While the yeast mitochondrial enzyme follows the pathway of posttransfer proofreading, the hen liver mitochondrial enzyme uses a tRNA-dependent pretransfer proofreading in the case of the natural amino acids. The accuracy of mitochondrial phenylalanyl-tRNA synthetases appears to be even better than the accuracy of the corresponding cytoplasmic enzymes. Interspecies rather than intraspecies differences for the functional role of certain amino acid residues of the enzymes further indicate the close relationship of the intracellular heterotopic isoenzymes. By use of a highly sensitive immunospotting procedure, common antigenic determinants are detected only within the enzymes from the two intracellular compartments of the same organism. The results suggest the origin of the cytoplasm-mitochondrion isoenzyme pair by independent gene duplication of the ancestral nuclear gene. A similarity of mitochondrial enzymes to the phenylalanyl-tRNA synthetase from Escherichia coli is not observed.

Adenosine Monophosphate↗
PubMed2003

When accuracy hurts, and when it helps: a test of the empathic accuracy model in marital interactions.

This study tested predictions from W. Ickes and J. A. Simpson's (1997, 2001) empathic accuracy model. Married couples were videotaped as they tried to resolve a problem in their marriage. Both spouses then viewed a videotape of the interaction, recorded the thoughts and feelings they had at specific time points, and tried to infer their partner's thoughts and feelings. Consistent with the model, when the partner's thoughts and feelings were relationship-threatening (as rated by both the partners and by trained observers), greater empathic accuracy on the part of the perceiver was associated with pre-to-posttest declines in the perceiver's feelings of subjective closeness. The reverse was true when the partner's thoughts and feelings were nonthreatening. Exploratory analyses revealed that these effects were partially mediated through observer ratings of the degree to which partners tried to avoid the discussion issue.

Adult↗
PubMed1991

Palpable masses in the prostate: superior accuracy of US-guided biopsy compared with accuracy of digitally guided biopsy.

The accuracies of digitally guided biopsy versus ultrasound (US)-guided biopsy of the prostate were compared in 112 consecutive men with palpable prostatic lesions who had previously undergone conventional digitally guided biopsy and in which the results were negative for carcinoma. US-guided biopsies were performed with either the transperineal (n = 51) or transrectal (n = 61) approach, by means of previously described methods. All US-guided biopsies were performed within 3 months after the most recent conventional biopsy. In 44 patients (39.3%) with negative results of conventional biopsies, the results of US-guided biopsy revealed cancer. The transrectal and transperineal digitally guided biopsies were equally inaccurate, and the transrectal and transperineal US-guided biopsies showed no statistically significant differences in accuracy. The patients accepted and tolerated both US techniques equally well; neither technique was associated with significant complications. It is concluded that all patients with a palpable nodule should undergo US-guided biopsy if the result of conventional digitally guided biopsy is negative for cancer and the diagnostic US scan suggests an abnormality.

Biopsy, Needle↗
PubMed1992

[Studies on dimensional accuracy of working casts made by various impression techniques--influence of undercuts on dimensional accuracy].

The purpose of this research was to evaluate the clinical acceptability of various impression techniques by comparing the dimensional accuracy of their working casts. An original metallic model was designed for this experiment. It has reference points to overlap and compare the master model and the working casts for measuring their dimensional accuracy under the same condition. The amount of distortion in each area of the working casts was examined by the measuring points within the model. The master model simulated an abutment for a full veneer crown with undercuts between the adjacent teeth. It was planned so that the amount of undercuts and distances between the adjacent teeth could be changed. As a result, a small distortion of the working casts due to the undercuts was observed by the technique using an individual tooth tray and polysulfide rubber base impression material. There was no significant dimensional change in the working casts made with silicone rubber base material. For the working casts made by hydrocolloid-alginate combination technique, the dimensional change was greater and distortion was observed in the abutment cast when the undercuts of the adjacent teeth were great. However, the distortion was less when the undercuts were small.

Dental Casting Technique↗
PubMed1999

Outpatient order accuracy. A College of American Pathologists Q-Probes study of requisition order entry accuracy in 660 institutions.

CONTEXT: Laboratory test order entry errors potentially delay diagnosis, consume resources, and cause patient inconvenience. OBJECTIVE: To evaluate the frequency and causes of computer order entry errors in outpatients. DESIGN: Cross-sectional survey and prospective sample of errors. Participants answered questions about their test order entry policies and practices. They then examined a sample of outpatient requisitions and compared information on the requisition with information entered into the laboratory computer system. Order entry errors were divided into 4 types: tests ordered on the requisition, but not in the computer; tests performed but not ordered on the requisition; physician name discrepancies; and test priority errors. PARTICIPANTS: Six hundred sixty laboratories enrolled in the College of American Pathologists Q-Probes program. MAIN OUTCOME MEASURE: Overall order entry error rate. RESULTS: A total of 5514 (4.8%) of 114 934 outpatient requisitions were associated with at least 1 order entry error. The median participant reported 1 or more order errors on 6.0% of requisitions; 10% of institutions reported errors with at least 18% of requisitions. Of the 4 specific error types, physician name discrepancies had the highest error rate, and test priority errors the lowest error rate. Four institutional factors were significantly associated with higher overall error rates: orders verbally communicated to the laboratory; no policy requiring laboratory staff to compare a printout or display of ordered tests with the laboratory requisitions to confirm that orders had been entered correctly; failure to monitor the accuracy of outpatient order entry on a regular basis; and a higher percentage of occupied beds (ie, a busier hospital). CONCLUSIONS: Computer order entry errors are common, involving 5% of outpatient requisitions. Laboratories may be able to decrease error rates by regularly monitoring the accuracy of order entry, substituting written and facsimile orders for verbal orders, and instituting a policy in which orders entered into computer systems are routinely rechecked against orders on requisitions.

Ambulatory Care↗
PubMed2005

[Health accuracy of Travnik cheese and quality standards of sanitary accuracy].

The aim of work was to determine a health accuracy of sheep milk and the final product Travnik cheese, as well as the quality standards of sanitary accuracy. The study was performed on 212 milk samples selected by random choice. The study involved observing the sanitary conditions of sheep milk and cheese production, as well as isolation and identification of causal agents of infective diseases in these products. The results showed the following agents isolated from milk and Travnik cheese: Escherichia coli from 179 samples (84.43%), Proteus spp. from 79 samples (37.26%), Coagulasis-positive Staphylococcus from 89 samples (41.98%) and sulfo-reducing Clostridium from 69 samples (32.54%). It is estimated that the health inaccuracy of Travnik cheese results from unsanitary conditions of sheep milk production, as well as the final product of Travnik cheese.

Animals↗
PubMed1980

A study of the accuracy, and factors influencing accuracy, of home addresses of patients obtained by registry clerks and address cards in four large towns in South India.

In 4 large towns in South India with illiteracy levels of 26% to 40%, the efficiency of registry clerks in eliciting the home addresses of 1338 out-patients was assessed, by verifying receipt of a letter posted to the patients. The efficiency was found to be very poor, namely 66%. Moreover, the accuracy of address was substantially poorer for illiterate patients and for patients living for relatively short durations at their present address. Our innovation, the address card, on which the home address was recorded by a knowledgeable literate person of the patient's choice, was returned by 98% of the patients, and the addresses were found accurate in 84%; the findings were similar in the 4 towns and were unaffected by any patient characteristic. The substantially better results with the address card were found in both illiterate and literate patients. These findings establish the address card as a simple, inexpensive and efficient device for obtaining accurate addresses.

Adult↗
PubMed1985

Evolutionary aspects of accuracy of phenylalanyl-tRNA synthetase. Accuracy of the cytoplasmic and chloroplastic enzymes of a higher plant (Phaseolus vulgaris).

The phenylalanyl-tRNA synthetases from cytoplasm and chloroplasts of bean (Phaseolus vulgaris) leaves employ different strategies with respect to accuracy. The chloroplastic enzyme that is coded for by the nuclear genome follows the pathway of posttransfer proofreading, also characteristic for enzymes from eubacteria and cytoplasm and mitochondria of lower eukaryotic organisms. In contrast, the cytoplasmic enzyme uses pretransfer proofreading in the case of noncognate natural amino acids, characteristic for higher eukaryotic organisms and archaebacteria. Dependent on the nature of the noncognate amino acid, pretransfer proofreading in this case occurs without tRNA stimulation or with tRNA stimulated with no or little effect of the nonaccepting 3'-OH group of the terminal adenosine. The fundamental mechanistic difference in proofreading between the heterotopic intracellular isoenzymes of the plant cell supports the idea of the origin of the chloroplastic gene by gene transfer from a eubacterial endosymbiont to the nucleus. Origin by duplication of the nuclear gene, as indicated for mitochondrial phenylalanyl-tRNA synthetases [Gabius, H.-J., Engelhardt, R., Schroeder, F.R., & Cramer, F. (1983) Biochemistry 22, 5306-5315], appears unlikely. Further analyses of the ATP/PPi pyrophosphate exchange and aminoacylation of tRNAPhe-C-C-A(3'NH2), using 11 phenylalanine analogues, reveal intraspecies and interspecies variability of the architecture of the amino acid binding part within the active site.

Amino Acyl-tRNA Synthetases↗
PubMed1984

Accuracy of death certificates in bronchial asthma. Accuracy of certification procedures during the confidential inquiry by the British Thoracic Association. A subcommittee of the BTA Research Committee.

The Research Committee of the British Thoracic Association conducted a confidential inquiry into death from asthma in adults aged 15-64 years resident in the West Midland and Mersey Regions during 1979. Death certificates recording the word asthma were received for 153 persons. The International Classification of Diseases code for the cause of death was obtained from the Office of Population Censuses and Surveys. Information about the patients, their illness, and their death was obtained by interviews, questionnaires, and inspection of patients' records. A panel of three physicians assisted by a pathologist assessed the clinical and, where applicable, the necropsy findings to ascertain whether bronchial asthma was the true cause of death. Of 147 assessable patients, 89 were considered by the panel to have died from asthma. In 77 of these cases the death certificates were correctly coded, whereas in 12 (13%) death was considered to have been wrongly attributed to another cause (falsely negative). Twenty four deaths on the other hand were considered to have been wrongly attributed to asthma (falsely positive). From this it appears that the total number of 101 certificates recording death from asthma represents a net overestimate of 13%. Accuracy was highest in the youngest age group. There were few discrepancies between the assessment of the panel and certified cause of death when a necropsy had been performed. The most common error (17% of all certificates) was failure to follow the procedure advised for completion of death certificates. This usually occurred when patients suffered from two or more conditions, or when death was sudden and necropsy was not performed.

Adolescent↗
PubMed1997

Accuracy of the Dinamap Portable Monitor, model 8100: a review of the evidence for accuracy.

Conventional measurement of blood pressure is fraught with many potential errors '1'. Automated blood pressure measuring devices remove observer bias and permit repeated blood pressure measurements at predetermined intervals, features which have obvious attractions in clinical practice and in hypertension and epidemiological research. However, such devices, which can be expensive, must be shown to be as accurate as the conventional technique which they are designed to replace '2'. A number of Dinamap models are available '3', the Dinamap Portable Monitor, Model 8100 (Critikon, Tampa, Flirida, USA) being one of the most popular automated devices used in clinical practice and in hypertension research, despite reports demonstrating that it is inaccurate in certain clinical circumstances. We therefore decided to review the literature on the Dinamap 8100. Ten papers '4-13' concerned specifically with the accuracy of this model were identified; they all acknowledged its inaccuracy but not all reached the same conclusions regarding the influence of such inaccuracy in practice.

Journal Article↗
PubMed2004

Lack of accuracy of continuous glucose sensors in healthy, nondiabetic children: results of the Diabetes Research in Children Network (DirecNet) accuracy study.

OBJECTIVE: The workup of hypoglycemia requires frequent glucose sampling. We designed these studies to determine if the Continuous Glucose Monitoring System (CGMS) and the GlucoWatch G2 Biographer (GW2B) are sufficiently accurate to use in nondiabetic children. Study design Fifteen healthy children (aged 9-17 years, 11 boys) wore a GW2B and a CGMS during a 24-hour period, and reference serum glucose was measured hourly during the day and half-hourly overnight. RESULTS: Compared with the reference glucose, the median absolute difference in concentrations measured by the GW2B (487 pairs) was 13 mg/dL, and the difference measured by the CGMS was 17 mg/dL (668 pairs), with 30% and 42% of values using the GW2B and CGMS, respectively, deviating >20 mg/dL from the reference value. The GW2B reported values <60 mg/dL in 73% of subjects, the CGMS in 60% of subjects. In none of these episodes was serum glucose truly low. Spurious high glucose concentrations also were observed with the sensors. The mean reference glucose was lowest at 5 am (89 mg/dL) and highest at 11:30 pm (106 mg/dL) during the 24-hour period. CONCLUSIONS: Neither the CGMS nor the GW2B is accurate enough to establish population standards of the glycemic profile of healthy children and cannot be recommended in the workup of hypoglycemia in nondiabetic youth.

Adolescent↗