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At least 1,297 records · Page 72Linked to original sources
PubMed2000

Diagnostic accuracy of dementia with Lewy bodies.

BACKGROUND: Diagnostic criteria for dementia with Lewy bodies (DLB) are still evolving. No data exist on prospective differentiation of DLB and Alzheimer disease (AD). OBJECTIVE: To examine the clinician's diagnostic accuracy for DLB and analyze factors contributing to false-positive DLB diagnoses. METHODS: A prospective series of 10 patients with clinically diagnosed DLB who came to autopsy was compared with 32 autopsy-confirmed cases of DLB (27 Lewy body variant, 5 diffuse Lewy body disease) and 20 autopsy-confirmed cases of AD (matched on age, sex, education, and initial Mini-Mental State Examination score) with regard to distinguishing and/or confounding clinical features. RESULTS: The clinical diagnostic accuracy for DLB was 50%, with 5 of the 10 patients clinically presumed to have DLB confirmed at autopsy. Of the 5 misdiagnosed cases, 4 had AD and 1 had progressive supranuclear palsy. The misdiagnosed DLB cases who had pure AD had fewer hallucinations (25%) than those with Lewy body variant (63%) or diffuse Lewy body disease (100%) (P = .048); however, an equal amount of spontaneous (in the absence of neuroleptics) extrapyramidal signs was found. There were no differences among groups with regard to daily fluctuations in cognition or falls. Compared with the AD control group, the misdiagnosed DLB cases with pure AD showed significantly more spontaneous extrapyramidal signs (P< or =.02). CONCLUSIONS: The clinician's diagnostic accuracy for DLB was poor. Early spontaneous extrapyramidal signs in AD were associated with false-positive clinical diagnoses of DLB. The distinction between DLB and AD may be improved by greater emphasis on hallucinations.

Aged↗
PubMed1989

Accuracy and precision of keratometry, photokeratoscopy, and corneal modeling on calibrated steel balls.

Surgical manipulation of corneal shape requires an accurate and precise method of measuring anterior corneal curvature from apex to limbus. We evaluated the accuracy and precision of the Bausch & Lomb Keratometer, Kera Corneascope, and Computed Anatomy Corneal Modeling System by measuring comparable locations on four calibrated steel test balls. The Keratometer and Corneal Modeling System were more accurate and precise than the Corneascope. No statistically significant difference was found between the Keratometer and Corneal Modeling System with respect to accuracy or precision. In addition, the accuracy and precision of all 31 rings of the Corneal Modeling System were studied. Rings 2 through 26 were read accurately and precisely within +/- 0.25 diopter on three of the four balls. Values on the steepest ball were within +/- 0.37 diopter.

Calibration↗
PubMed2001

Occult primary tumors of the head and neck: accuracy of thallium 201 single-photon emission computed tomography and computed tomography and/or magnetic resonance imaging.

OBJECTIVE: To determine the accuracy of thallium 201 single-photon emission computed tomography (thallium SPECT) and computed tomography and/or magnetic resonance imaging (CT/MRI) in the detection of occult primary tumors of the head and neck. DESIGN: Study of diagnostic tests. SETTING: National Cancer Institute, Amsterdam, the Netherlands. PATIENTS AND METHODS: Thirty-two patients with a neck node metastasis of an epithelial tumor and negative findings by mirror examination at initial presentation were included in the study. Twenty-nine patients underwent thallium SPECT and CT/MRI before examination under general anesthesia (EUA). In 3 patients only thallium SPECT was performed before EUA. Histological confirmation of an occult primary tumor during EUA was used as the gold standard. Negative radiodiagnostic and nuclear findings in the upper aerodigestive tract in the presence of a primary carcinoma other than of the head and neck were interpreted as true-negative findings. RESULTS: For thallium SPECT the following results were recorded: sensitivity, 67%; specificity, 69%; accuracy, 69%; positive predictive value, 33%; and negative predictive value, 90%. In 1 patient, thallium whole body scan indicated a primary carcinoma beyond the mucosal lining of the upper aerodigestive tract. The CT/MRI results were as follows: sensitivity, 71%; specificity, 73%; accuracy, 72%; positive predictive value, 45%; and negative predictive value, 89%. CONCLUSIONS: Thallium SPECT and CT/MRI showed comparable results for detection of occult primary tumors of the head and neck. A potential advantage of thallium SPECT is that it allows total body screening.

Adult↗
PubMed2004

Diagnostic accuracy of magnetic resonance imaging in the assessment of mandibular involvement in oral-oropharyngeal squamous cell carcinoma: a prospective study.

OBJECTIVE: To evaluate the sensitivity, specificity, accuracy, and predictive values of magnetic resonance imaging (MRI) in the assessment of mandibular involvement in oral-oropharyngeal squamous cell carcinoma. DESIGN: Prospective study. SETTING: University hospital. PATIENTS: Forty-three patients with oral or oropharyngeal squamous cell carcinoma undergoing marginal or segmental mandibulectomy between January 1, 1994, and January 31, 2003. INTERVENTIONS: Indications for mandibulectomy were MRIs suggestive of bony invasion, tumor involving the retromolar trigone or the alveolar ridge, recurrent or persistent lesion, or intraoperative suspicion of periosteal invasion. Detection of tumor signal replacing the hypointense cortical rim was considered the main radiologic finding for mandibular invasion. MAIN OUTCOME MEASURES: The MRI findings were subsequently compared with histopathologic data of surgical specimens with reference to the presence of cortical and/or medullary mandibular involvement. RESULTS: Sixteen patients had MRI findings suggestive of mandibular involvement. Segmental mandibulectomy was performed in 15 cases and marginal resection in the remaining case. In 14 patients, bony invasion was confirmed. All of the other 27 patients who underwent marginal or segmental mandibulectomy with negative MRI findings had no histopathologic evidence of mandibular involvement, except in 1 patient: on histopathologic examination, despite cortical integrity, neoplastic vascular embolization into the bony lacunae was detected. Sensitivity of MRI in detecting mandibular involvement was 93%; specificity, 93%; accuracy, 93%; and negative and positive predictive values, 96% and 87.5%, respectively. CONCLUSIONS: Magnetic resonance imaging is commonly considered the technique of choice for treatment planning in advanced oral and oropharyngeal squamous cell carcinoma because of its accuracy in depicting soft-tissue involvement. This study demonstrates the additional diagnostic value of MRI in detecting bone invasion.

Adult↗
PubMed1975

Accuracy of the Bing and Rinne tuning fork tests.

Fifty children seen in an ENT clinic received the Bing and Rinne tuning fork tests, otoscopic examination, and puretone audiometry to determine the accuracy of the tuning fork tests in predicting otoscopic abnormality or conductive hearing loss. Neither tuning fork test showed high accuracy. The Bing test overidentified by yielding negative results (conductive loss) for many ears with normal hearing or sensorineural loss. It correctly identified conductive loss or otoscopic abnormality only slightly better than chance57% to 66% of the time. The Rinne test identified with high accuracy those ears with a 40 dB or greater air-bone gap. For air-bone gaps of 10-35 dB, only 27% of the ears gave negative results, meaning correct identification. However, when a negative Rinne occurred, the result was in error only 2% of the time.

Adolescent↗
PubMed1992

Accuracy of pathologic diagnosis in thyroid lesions.

Although there is much literature devoted to the role that fine-needle biopsy plays in the management of the thyroid mass, only a handful of studies deal with the diagnostic accuracy of the frozen section and final paraffin section of thyroid lesions. Fine-needle biopsy results, frozen-section diagnoses, final paraffin-section diagnoses, and panel review diagnoses were recorded for 137 consecutive patients who underwent thyroidectomy procedures. The overall accuracy of fine-needle biopsy, frozen-section, and paraffin-section diagnoses was 81%, 87%, and 94%, respectively. The high positive predictive value and specificity of both the fine-needle and frozen-section modalities suggests that intraoperative pathology consultation, given that the preoperative needle aspirate is positive for malignant neoplasia, can offer little further in the treatment of the patient. Statistical analysis of the accuracy of the three modalities suggests strategies for accurate treatment of the thyroid nodule.

Adolescent↗
PubMed2001

Accuracy of a noninvasive temporal artery thermometer for use in infants.

OBJECTIVES: To assess the accuracy of a new noninvasive temporal artery (TA) thermometer in infants; to compare the accuracy of the TA thermometer with that of a tympanic thermometer, using rectal thermometry as the criterion standard; and to compare the tolerability of the TA thermometer with that of the tympanic and rectal thermometers. DESIGN: Prospective evaluation of the accuracy of TA and tympanic thermometry, using rectal thermometry as the criterion standard. SETTING: Emergency department of an urban pediatric hospital. SUBJECTS: Convenience sample of 304 infants younger than 1 year presenting for care. MAIN OUTCOME MEASURES: Temperatures were measured using TA, tympanic, and rectal thermometers for all infants. Agreement between TA or tympanic and rectal temperatures was assessed. The sensitivity and specificity of TA or tympanic thermometers for detecting rectal fever were determined. Discomfort scores, using a standardized scale, were assessed by trained observers after each temperature measurement was made. RESULTS: Linear regression analysis of the relation between TA and rectal temperatures yielded a model with a slope of 0.79 (vs a slope of 0.68 for tympanic vs rectal temperature; P =.02) and an r of 0.83 (vs r = 0.75 for tympanic vs rectal temperature; P<.001). Among 109 patients with a rectal temperature of 38 degrees C or higher, the TA thermometer had a sensitivity of 0.66 compared with the tympanic thermometer's sensitivity of 0.49 (P<.001). Discomfort scores with TA thermometry were significantly lower than with rectal thermometry (P =.007). CONCLUSIONS: The TA thermometer has limited sensitivity for detecting cases of rectal fever in infants. However, the TA thermometer is more accurate than the tympanic thermometer in infants, and it is better tolerated by infants than rectal thermometry.

Body Temperature↗
PubMed2005

Oxycodone vs placebo in children with undifferentiated abdominal pain: a randomized, double-blind clinical trial of the effect of analgesia on diagnostic accuracy.

BACKGROUND: Analgesics for children with acute abdominal pain are often withheld for fear that they might mask physical examination findings and thus might be unsafe. This viewpoint has been challenged recently. OBJECTIVE: To evaluate the effects of buccal oxycodone on pain relief, physical examination findings, diagnostic accuracy, and final clinical outcomes in children with acute abdominal pain. DESIGN: Prospective, randomized, double-blind, and placebo-controlled trial between December 2001 and November 2003. SETTING: University teaching hospital in Finland. Patients A total of 104 children aged 4 to 15 years with abdominal pain of less than 7 days' duration were screened, and 63 children with pain scores of 5 or higher on a 10-cm visual analog scale were eligible for the trial. Intervention Children were randomized to receive buccally either 0.1 mg/kg(-1) of oxycodone hydrochloride (n = 32) or the same volume of normal saline (n = 31). The same surgeon described the physical findings and indicated a provisional diagnosis and a provisional disposition before the children received the study medication and at 1 hour and 3.5 hours after initial dosing. Pain scores were recorded at baseline and every 30 minutes for 3.5 hours after the first study drug administration. MAIN OUTCOME MEASURES: Pain intensity difference, presence or absence of abdominal guarding, and diagnostic accuracy. RESULTS: The demographic characteristics, initial pain scores, and physical signs and symptoms were similar between the 2 groups. Both study drugs were associated with decreasing pain scores. The summed pain intensity difference over 7 observations was significantly greater in the oxycodone group, 22 +/- 18 cm, than in the placebo group, 9 +/- 12 cm (mean difference 13 cm, with a 95% confidence interval of 2-24 cm; P = .04). The diagnostic accuracy increased from 72% to 88% in the oxycodone group and remained at 84% in the placebo group after study drug administration. Laparotomy was performed in 17 patients in the oxycodone group and in 14 patients in the placebo group. Four patients without appendicitis underwent exploratory laparotomy in each group. One patient in the placebo group was initially diagnosed as having nonspecific abdominal pain, but at 14 hours, she was operated on for appendiceal perforation. CONCLUSIONS: Early administration of buccal oxycodone provides a significant pain relief to children with acute abdominal pain, without adversely altering the clinical signs or obscuring the surgical diagnosis.

Abdominal Pain↗
PubMed1992

Assessment of otoscopists' accuracy regarding middle-ear effusion. Otoscopic validation.

Validation of otoscopic diagnostic accuracy is an important aspect of medical education and is necessary to substantiate clinical research observations. In addition, otoscopic accuracy is a prerequisite to optimal patient care. We describe an otoscopic validation program at the Children's Hospital of Pittsburgh (Pa) in which 27 physicians and three nurse practitioners participated from December 1980 to March 1990. The lowest acceptable limits for sensitivity and specificity regarding the diagnosis of middle-ear effusion were arbitrarily set at 80% and 70%, respectively. The 30 participating clinicians examined a total of 4147 ears. Mean sensitivity and mean specificity for the group as a whole were 87% and 74%, respectively. The chief benefit of the program was an improvement in diagnostic skills for some individuals. The chief limitation was the large amount of time required. We conclude that a formal validation program can document achievement of a reasonable standard of otoscopic diagnostic accuracy.

Child↗
PubMed2006

Diagnostic accuracy of colorectal cancer staging with whole-body PET/CT colonography.

CONTEXT: Staging of patients with colorectal cancer often requires a multimodality, multistep imaging approach. Colonography composed of a combined modality of positron emission tomography (PET) and computed tomography (CT) provides whole-body tumor staging in a single session. OBJECTIVES: To determine the staging accuracy of whole-body PET/CT colonography compared with the staging accuracies of CT followed by PET (CT + PET) and CT alone and to evaluate the effect of PET/CT colonography on therapy planning compared with conventional staging (CT of the abdomen and thorax and optical colonoscopy). DESIGN, SETTING, AND PATIENTS: Prospective study of 47 patients enrolled between May 2004 and June 2006 with clinical findings and optical colonoscopy that suggested primary colorectal cancer (mean [SD] age, 71 [11] years; range, 47-92 years). Patients underwent whole-body PET/CT colonography 1 day after colonoscopy. The study was conducted at a university hospital with a mean (SD) follow-up of 447 (140) days (range, 232-653 days). MAIN OUTCOME MEASURES: Correct classification of overall TNM stage using PET/CT colonography compared with CT + PET and CT alone. Secondary outcome measures were the accurate assessment of T-stage, N-stage, and M-stage by PET/CT colonography compared with CT + PET and CT alone and the effect of PET/CT colonography on therapy planning. RESULTS: Of the 47 patients with a total of 50 lesions, the overall TNM stage was correctly determined for 37 lesions with PET/CT colonography (74%; 95% confidence interval [CI], 60%-85%), 32 lesions with CT + PET (64%; 95% CI, 49%-77%), and 26 lesions with CT alone with a 0.7-cm node threshold (52%; 95% CI, 37%-66%). Compared with optimized abdominal CT staging alone, PET/CT colonography was significantly more accurate in defining TNM stage (difference, 22%; 95% CI, 9%-36%; P=.003), which was mainly based on a more accurate definition of the T-stage. Differences were not detected for defining N-stage between PET/CT colonography and CT alone with a threshold of 0.7 cm for malignant nodes but were detected with a threshold of 1 cm. Differences were not detected in defining M-stage separately or when comparing the accuracies of PET/CT colonography with CT + PET. PET/CT colonography affected consecutive therapy decisions in 4 patients (9%; 95% CI, 2.4%-20.4%) compared with conventional staging (CT alone and colonoscopy). CONCLUSIONS: In this preliminary study, PET/CT colonography is at least equivalent to CT + PET for tumor staging in patients with colorectal cancer. Thus, PET/CT colonography in conjunction with optical colonoscopy may be a suitable concept of tumor staging for patients with colorectal cancer.

Aged↗
PubMed2026

Diagnostic Accuracy of a CRISPR-Based Assay in Smear- and Culture-Negative Fungal Keratitis.

IMPORTANCE: Diagnosing fungal keratitis (FK) in patients with negative smear and culture results remains clinically challenging, highlighting the need for alternative diagnostic approaches. OBJECTIVE: To determine the diagnostic accuracy of the clustered regularly interspaced short palindromic repeats (CRISPR)-based Rapid Identification of Mycoses using CRISPR (RID-MyC) assay for detecting FK in patients with negative smear and culture results using in vivo confocal microscopy (IVCM) as the reference standard. DESIGN, SETTING, AND PARTICIPANTS: This prospective diagnostic accuracy study was conducted from December 2024 to March 2025 at Aravind Eye Hospital, a tertiary ophthalmology referral hospital in Coimbatore, India. Consecutive patients clinically suspected to have microbial keratitis with negative smear and culture results were eligible for inclusion. Data were analyzed from March 2025 to June 2025. INTERVENTIONS: All included participants underwent corneal scraping for RID-MyC assay and imaging by IVCM. MAIN OUTCOMES AND MEASURES: The primary outcomes were sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic concordance of the RID-MyC assay compared with IVCM results. RESULTS: Of 245 consecutive patients clinically suspected to have microbial keratitis, 82 were smear negative. After exclusions due to contraindications or positive subsequent cultures, 41 patients with smear- and culture-negative results were ultimately included in the final analysis. Of these 41 patients (mean [SD] age, 51.0 [14.6] years; 21 [51.2%] women), RID-MyC demonstrated sensitivity of 82.1% (95% CI, 63%-94%) and specificity of 76.9% (95% CI, 46%-95%). Positive predictive value was 88.5% (95% CI, 74%-95%) and negative predictive value was 66.7% (95% CI, 46%-82%). Concordance between RID-MyC and IVCM was observed in 33 cases (80.5%). Notably, prior antifungal treatment was most frequent (4 of 5 [80%]) among patients with positive IVCM but negative RID-MyC results. Conversely, all patients (3 of 3 [100%]) with negative IVCM but positive RID-MyC findings had smaller, peripheral, or paracentral lesions. CONCLUSIONS AND RELEVANCE: In this diagnostic study, in patients with smear- and culture-negative FK, the RID-MyC assay showed good diagnostic accuracy comparable with IVCM and was feasible in all cases, including those in whom imaging was not possible. With its rapid turnaround and minimal equipment needs, RID-MyC may serve as a practical adjunct to conventional diagnostics, particularly in high-burden, resource-limited settings where IVCM is unavailable or contraindicated.

Humans↗
PubMed1997

Competitive assessment of protein fold recognition and alignment accuracy.

The predictions made for fold recognition and modeling accuracy at the 1996 Critical Assessment of Structure Prediction meeting (CASP2) were assessed to discover which groups did best. With 32 groups making a total of 369 predictions, it was necessary to use simple criteria for distinguishing between the entries. By focusing on the predictors' ability to use the sequence of the unknown target structure to recognize the target fold from a database of known folds and also on the quality of the model judged by the accuracy of the predicted alignment, it is easy to determine the best predictions for a given target. Assessing overall performance of the predictors on all the targets is much more difficult and use was made of weighted averages of fold recognition and alignment accuracy with and without normalization for target difficulty. By plotting these results in two dimensions the winning groups stand out, allowing readers to focus their attention on the most promising methods. When the present results are compared with the results of the earlier CASP1 meeting, held in 1994, it is clear that threading predictions have progressed dramatically. For this assessor, the strongest lesson learned is that subjectivity is pervasive and affects us all. It is abundantly clear that the blind predictions made at CASP are essential if progress is to be made in predicting protein structure.

Models, Molecular↗
PubMed1997

Accuracy, efficacy, and clinical applications of the Radionics Operating Arm System.

The aim of this study was to evaluate the accuracy and efficacy of the Radionics Operating Arm System (OAS; Radionics Applications Software, Burlington, MA) in a routine clinical setup. The OAS is a frameless stereotactic articulated arm that can be used in conjunction with computed tomography (CT) or magnetic resonance (MR) imaging to provide image-based intraoperative navigation. The system was used in 130 consecutive cases. It failed or was considered unreliable in 4.6% of patients. Among the remaining patients, 103 had OAS-guided craniotomies, 11 had frameless stereotactic biopsies, and 10 had OAS-guided anterior cervical surgery. Patients were imaged 3-12 hours prior to surgery. Skin markers were used in all cases. The OAS accuracy was evaluated by measuring the difference between the actual probe position and its analogous position on the images. Frameless stereotactic biopsies were performed using the OAS, a modified probe, and a twist-drill. Anterior cervical surgery was performed using the OAS, MRI images, and a rigid cervical collar. The duration of the procedure was recorded for the first 50 patients, and the value of the OAS in localizing the site of craniotomy, the margin of the lesion, and the extent of the resection was also recorded. The system was associated with insignificant prolongation of procedure setup and was sufficiently reliable and achieved a useful registration in 124 (95.4%) patients. The mean accuracy of the system, using skin markers, was 2.5 mm. The OAS was also adaptable for performing other tasks, such as an interactive needle biopsy without a frame. Its use in conjunction with a hollow probe, to perform biopsy or aspiration of 11 brain lesions, produced 100% positive results. Its use in conjunction with MRI and a cervical collar fiducial system, to perform anterior cervical surgery in 10 patients, localized the level in all patients. Overall, the Radionics OAS was sufficiently reliable and accurate in a wide range of routine neurosurgical procedures. Therefore, we integrated it into our routine neurosurgical practice.

Adolescent↗
PubMed1998

Accuracy of registration methods in frameless stereotaxis.

The accuracy of image to patient registration is a critical issue in the intraoperative use of frameless stereotaxic instruments for surgical guidance. This study was performed to assess the accuracy of image to head phantom registration using several standard registration techniques and a clinical frameless stereotaxic instrument. Two types of radioopaque fiducial markers were fixed to a plastic head phantom, and a computed tomography scan of the phantom was performed in the routine fashion. Image to phantom registration was carried out using fiducial markers, fiducial markers plus surface fit, anatomic landmarks, and anatomic landmarks plus surface fit. After each registration, linear inaccuracy measurements were performed for each of 32 markers. Each registration was performed 10 times, and the overall mean error measurements and anterior and posterior error were computed and compared. The overall mean error was smallest for the fiducial registration alone (2.07 mm). The magnitude of error increased significantly for posterior locations for all other registration techniques, but it was not significantly increased for the fiducial registration method. For this hardware configuration, registration with surface-applied fiducial markers is measurably more accurate than registration with surface anatomic landmarks. The addition of surface points to the fiducial registration does not increase the registration accuracy but, in fact, increases the degree of error.

Computer Systems↗
PubMed1998

Prevalence of cervicovaginal infections during gestation and accuracy of clinical diagnosis.

OBJECTIVES: The aim of this study was to establish the prevalence of cervicovaginal infections in normal third-trimester pregnant women and evaluate the accuracy of clinical diagnosis. METHOD: A total of 328 pregnant women were followed at the Prenatal Outpatient Clinic of the Department of Obstetrics and Gynecology at the School of Medical Sciences, Universidade Estadual de Campinas (UNICAMP), Brazil, from October 1991 to February 1993. The clinical diagnosis was based on the characteristics of the vaginal discharge, and the etiological diagnosis was based on bacterioscopy of the vaginal secretion and direct immunofluorescence for Chlamydia trachomatis. The data were analyzed statistically, determining the sensitivity, specificity, and positive and negative predictive value of the clinical diagnosis related to the laboratory diagnosis of the different infections. RESULTS: The prevalence of infection was 39.6% (Candida albicans, 19.2%; bacterial vaginosis, 9.5%; intermediate vaginal flora, 6.7%; Chlamydia trachomatis, 2.1%; and vaginal trichomoniasis, 2.1%). The accuracy of clinical diagnosis was low, with sensitivity between 50% and 65% and specificity around 60%, with the exception of trichomoniasis, which showed a sensitivity of 100% and chlamydia, with a sensitivity of 0% and a specificity of 100%. CONCLUSION: The accuracy of the clinical diagnosis of infections was low, specifically with respect to the positive predictive value. The results demonstrate the need for specific testing of cervicovaginal infections at prenatal visits. Reliance on simple vaginal examination results in a low yield for detection of vaginal infections.

Adolescent↗
PubMed1999

Accuracy of proband reported family history: the NHLBI Family Heart Study (FHS).

Proband-reported family histories are widely used in research and counseling, yet little is known about the validity of family history reporting. The Family Heart Study (FHS), a population-based study of familial cardiovascular disease, gathered family history information from 3,020 middle-aged probands in four U.S. communities. Probands reported on the history of coronary heart disease (CHD), diabetes, hypertension, and asthma among a total of 10,316 living relatives (9,186 siblings, 1,130 parents) and 2,685 spouses. Questionnaires were returned by 6,672 siblings, 901 parents, and 2,347 spouses, yielding response rates of 73, 79, and 87%, respectively. Utilizing the relatives' self-report as the standard, sensitivity of the proband report on their spouse, parent, and sibling was 87, 85, and 81% for CHD, 83, 87, and 72% for diabetes, 77, 76, and 56% for hypertension, and 66, 53, and 39% for asthma, respectively. Most specificity values were above 90%. Analyses using generalized estimating equations (GEE) were performed to evaluate differences in proband accuracy based on the proband's age, gender, disease state, center, and ethnicity. In multivariate models, age, gender, and disease status were significantly associated with the accuracy of proband's report of sibling disease history, but had little effect on the accuracy of their report on spouses or parents. In general, older probands were significantly less accurate reporters of disease than younger probands. These results demonstrate that CHD family history can be captured effectively based on proband reports, but suggest that additional family contacts may be helpful when working with older probands or with chronic diseases that have few recognized medical events or procedures.

Asthma↗
PubMed1999

Diagnostic accuracy of oropharyngeal cultures in infants and young children with cystic fibrosis.

The objective of this study was to assess the diagnostic accuracy of oropharyngeal (OP) cultures relative to simultaneous bronchoalveolar lavage (BAL) cultures in very young children with CF, and to examine the effects of bacterial density, age, and study cohort on diagnostic accuracy. Respiratory culture data were analyzed from three independent, prospective studies involving simultaneous collection of 286 OP and BAL cultures from 141 children with CF <5 years of age. For predicting any growth of Pseudomonas aeruginosa (Pa) from the lower airway in subjects </=18 months of age (mean age, 8 +/- 5 months), OP cultures had a sensitivity of 44% (95% CI 14%, 79%), specificity of 95% (90%, 99%), positive predictive value of 44% (14%, 79%), and negative predictive value of 95% (90%, 99%). Diagnostic accuracy was similar for Haemophilus influenzae (Hi). Specificity was significantly lower for Staphylococcus aureus (Sa). Sensitivity for all organisms improved if a positive lower airway culture was defined as >/=10(3) or >/=10(5) cfu/mL. Specificity for Pa declined significantly with increasing age. In children with CF <5 years of age, the specificity and negative predictive value of OP cultures for Pa are high, while the sensitivity and positive predictive value are poor. Thus, in this age range, a negative throat culture is helpful in "ruling out" lower airway infection with Pa. However, a positive culture does not reliably "rule in" the presence of Pa in the lower respiratory tract. These findings may have implications for study design and interpretation as well as clinical management of young children with CF.

Bacterial Infections↗
PubMedDate not supplied

Methods for assessing accuracy and reliability in functional MRI.

In this paper, methods for assessing the accuracy and the reliability of functional magnetic resonance imaging techniques are presented. First, a modified receiver operating characteristic analysis is described for evaluating the accuracy of fMRI studies. With this modified approach, the true positives or the activated pixels are estimated based on highly averaged experimental data acquired with the same stimulation/task. Unlike ROC analysis based on simulated activation data, the present approach can be applied to experimentally acquired data without simplifying the activation related changes. To assess the reliability of fMRI studies, the kappa statistic was adopted for evaluating the overall agreement of functional activation maps from repeated experiments in individual subjects. To demonstrate the utility of these techniques, both the ROC analysis and the reliability assessment were applied to quantitatively evaluate the improvement in accuracy and reliability of a retrospective technique for physiological noise reduction in fMRI.

Magnetic Resonance Imaging↗