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Biomedical subjects

T R TenHave

Publications and source records attributed to T R TenHave.

At least 19 recordsLinked to original sources
PubMed2001

Risk screening in a medicare/medicaid population administrative data versus self report.

OBJECTIVE: To compare the abilities of two validated indices, one survey-based and the other database-derived, to prospectively identify high-cost, dual-eligible Medicare/Medicaid members. DESIGN: A longitudinal cohort study. SETTING: A Medicaid health maintenance organization in Philadelphia, Pa. PARTICIPANTS: HMO enrollees (N = 558) 65 years and older eligible for both Medicare and Medicaid. MEASUREMENTS AND MAIN RESULTS: Two hundred ninety six patients responded to a survey containing the Probability of Repeat Admission Questionnaire (Pra) between October and November 1998. Using readily available administrative data, we created an administrative proxy for the Pra. Choosing a cut point of 0.40 for both indices maximized sensitivity at 55% for the administrative proxy and 50% for the survey Pra. This classification yielded 103 high-risk patients by administrative proxy and 73 by survey Pra. High-cost patients averaged at least 2.3 times the resource utilization during the 6-month follow-up. Correlation between the two scores was 0.53, and the scales disagreed on high-cost risk in 78 patients (54 high-cost by administrative proxy only, and 24 high-cost by survey Pra only). These two discordant groups utilized intermediate levels of resources, $2,171 and $2,794, that were not statistically significantly different between the two groups (probability > chi2 =.66). Receiver operating characteristic curve areas (0.68 for survey Pra and administrative proxy for respondents, and 0.67 by administrative proxy for nonrespondents) revealed similar overall discriminative abilities for the two instruments for costs. CONCLUSIONS: The Medicaid/Medicare dual-eligible population responded to the survey Pra at a rate of 53%, limiting its practical utility as a screening instrument. Using a cut point of 0.40, the administrative proxy performed as well as the survey Pra in this population and was equally applicable to nonrespondents. The time lag inherent in database screening limits its applicability for new patients, but combining database-driven and survey-based approaches holds promise for targeting patients who might benefit from case management intervention.

Aged↗
PubMed1999

Detection of Björk-Shiley convexo-concave heart valve outlet strut single leg separations: consensus image acquisition and interpretation using two different cineradiographic imaging technologies.

BACKGROUND: Conventional cineradiology has been used clinically to detect partially broken outlet struts (single leg separations, SLSs) in normally functioning Björk-Shiley convexo-concave (C/C) heart valves. The value of radiographic screening has, however, been debated in the medical literature. This study uses the same radiographic technique in sheep implanted with known-status C/C valves in combination with a newly developed geometric image magnification radiography system. This study was designed to test whether sensitivity and specificity of radiographic screening of C/C valves in detecting SLSs could be improved through the combination of readers and imaging modalities. METHODS: Twenty-one sheep with mitral C/C valves were studied on both systems. Five were used for extensive scanning training. When operators were expert on both systems, 16 blinded study valves (4 intact and 12 with outlet strut SLSs) were scanned twice on both systems, first on a modified conventional and then a prototype geometric image magnification (Feinfocus(TM)) cineradiographic system by two expert physicians working together. RESULTS: Among the 32 scanned valves, the two combined expert physicians were required to evaluate 40 intact legs and 24 with an SLS. For all SLS valves, the conventional and Feinfocus systems separately detected 50 (12/24) and 54% (13/24), respectively. When the two systems were combined, the final consensus score was correct in 67% (16/24) of all SLS valves. CONCLUSIONS: Combined modality, paired expert physicians detected 67% of all SLSs. The Feinfocus system might be best reserved for those patients in whom the Siemens screening study demonstrates in minimally suspicious (grade 2) or suspicious (grade 3) appearance of a C/C valve outlet strut leg.

Animals↗
PubMed1998

In vivo accuracy of two radiographic systems in the detection of Björk-Shiley convexo-concave heart valve outlet strut single leg separations.

OBJECTIVE: Modified cineradiographic systems have been used clinically to detect partially broken outlet struts in normally functioning Björk-Shiley convexo-concave heart valves. Almost all such valves were explanted, presuming that full failure would likely follow. Inasmuch as the clinical setting only rarely permits examination of normally rated valves, the accuracy of radiographic detection cannot be clinically defined. This study uses the clinical radiographic technique in sheep implanted with known-status convexo-concave valves, comparing its accuracy and that of a newly developed, geometric image magnification radiography system. METHODS: Twenty-one sheep with mitral convexo-concave valves were studied on both systems. Five were used for extensive training. When operators were expert with both systems, images of four intact valves and 12 valves with outlet strut single leg separations, along with a seventeenth single leg separation valve used for calibration, were integrated into 112 image sets organized into a balanced incomplete block design for evaluation by eight trained, blinded reviewers. RESULTS: Cineradiography sensitivity was 24% versus 31% for direct image magnification. The odds ratio for detection of single leg separation by direct image magnification versus cineradiography was 2.0 (95% confidence interval, 0.76 to 5.9; p = 0.13). Cineradiography specificity was 93% versus 90% for direct image magnification. Sensitivity and specificity varied markedly by reviewer, with sensitivity ranging from 8% to 55% and specificity from 51% to 100% for the combined technologies. CONCLUSIONS: The data support the need for more intensive training for convexo-concave valve imaging and further investigation of unconventional radiographic technologies. Clinical cineradiography of convexo-concave valves may detect as little as 25% of valves having a single leg separation, underestimating the prevalence of single leg separations and thereby implying more rapid progression to full fracture than is actually the case.

Animals↗
PubMed1998

The readability of currently used surgical/procedure consent forms in the United States.

BACKGROUND: Informed consent forms are universally used by hospitals throughout the United States before surgery or invasive procedures. This survey was undertaken to determine the content of these forms and their ability to be understood by individuals with differing reading comprehension levels. METHODS: Ten percent of all U.S. hospitals were requested to forward a copy of their current surgical/procedural informed consent form. The forms received were digitized and computer assessed for readability. In addition, each form was evaluated for a variety of items with respect to content. RESULTS: Of the 2194 requests mailed, 681 responses were received including 616 with surgical/procedural consent forms. The mean grade level required to understand these consent forms was 12.6 (+/- 3.1). There was no variability in readability scores on the basis of hospital bed size. Of the 616 consent forms reviewed, 29, 146, 347, and 461 forms could be understood by individuals reading at a grade level of less than 8 and at least 8, 10, and 12 years of education, respectively. Although most required the name of the patient, physician, and procedure, the majority did not describe or provide a full-in blank for the specific benefits, risks, and alternatives to the procedure. CONCLUSIONS: The majority of surgical/procedural informed consent forms currently used by U.S. hospitals are complex and are not easily understood by the average patient. In addition, the majority of reviewed consent forms do not list specific benefits or potential complications of the planned surgery/procedure.

Hospitals↗
PubMed1998

CT bronchoscopy: optimization of imaging parameters.

The authors evaluated the relative importance of the following scanning parameters at computed tomographic bronchoscopy in an anesthetized adult sheep's thorax: section thickness (2, 4, 8 mm), pitch (1.0, 1.5, 2.0), milliampere setting (100, 175, 250 mA), and overlap of reconstructed sections (0%, 25%, 50%, 75%). Five blinded readers ranked the images twice in comparison with photographs of the mounted specimen. Differences in image quality were significant (P < .001) with section thickness of 2 mm and a pitch of 1.0. The milliampere setting had only a minor effect on image quality, and a 50% overlap of reconstructed sections was best.

Animals↗
PubMed1997

Literacy assessment in a cardiovascular nutrition education setting.

We assessed functional literacy of hypercholesterolemic or hypertensive African Americans (n = 339) prior to their participation in a nutrition education program. A word pronunciation and recognition test using 20 common cardiovascular or nutrition terms was first developed based on correlations with standardized reading achievement test scores, then administered to program participants. Nearly half (48%) had word recognition scores equivalent to a < or = 8th grade reading level. Lower scores were associated with less education, lower income, unemployment, heavier work activity if employed, less healthy diets, history of heart disease or diabetes, and higher depression scores (all P < 0.01); several of these associations were independent of education. The educational materials were geared to a 5th to 8th grade reading level. However, when both audiotaped and printed instruction were provided, individuals with reading scores < or = 8th grade preferentially used the tapes. This brief and relatively unobtrusive literacy assessment may help to identify persons who can benefit most from audiovisual approaches to cardiovascular nutrition education.

Adult↗
PubMed1997

The public release of hospital and physician mortality data in Pennsylvania. A case study.

OBJECTIVES: Using the public reports of the Pennsylvania Health Care Cost Containment Council on coronary artery bypass graft surgery for 1990 to 1992 as a case study, the authors assess the sensitivity of results to the choice of data and statistical methodology. METHODS: Using the Council's public-release data, surgical mortality and utilization were reanalyzed by standard linear models, empirical Bayes methods, Monte Carlo simulations, and hierarchical statistical models. RESULTS: Statistical power calculations demonstrate that the annual volume of bypass surgery for many hospitals and for most surgeons is too small for meaningful mortality comparisons. The number of hospitals and physicians designated as mortality "outliers" in the Council's reports results in part from a failure to adjust critical P values for multiple comparisons. Hierarchical statistical models implemented by mixed effects logistic regression, by contrast, can detect true differences in performance without producing false outliers. Mortality analyses are sensitive to the choice of comorbidities used for severity adjustment of a mortality model. Small-area analyses indicate large differences in the rates of bypass surgery across Pennsylvania, with lower population-based rates of surgery associated with higher population-based inpatient mortality. CONCLUSIONS: Analyses of mortality by operative procedure, rather than by patient diagnosis, should consider the potential for selection bias caused by the decision to elect surgery. The clinical and statistical issues of operative mortality are sufficiently complex to merit review by independent experts before public release of hospital and physician performance measures.

Cardiology Service, Hospital↗
PubMed1997

Thoracic spiral CT: delivery of contrast material pushed with injectable saline solution in a power injector.

A method of power injection of contrast material pushed with injectable saline solution during thoracic computed tomography (CT) was evaluated in 75 patients to help decrease the amount of contrast material necessary. Patients received 50-125 mL of 60% nonionic contrast material alone or pushed with 50 mL of saline. A volume of 75 mL of contrast material pushed with saline provided enhancement of the thoracic vasculature equal to that provided by a 125-mL volume of contrast material administered alone (P < .001) and caused significantly less beam-hardening artifact (P < .01).

Aorta, Thoracic↗
PubMed1997

Gel tubes: a method of core-specimen retrieval and transport.

The utility of saving core biopsy specimens in sterile gel tubes was evaluated with 30 liver and 30 kidney core specimens obtained at open biopsy with an 18-gauge needle during autopsy. The core specimens were saved with one of three methods: gel tube, formalin swirl, or scalpel retrieval. The combined-organ mean time for the radiologist to save core specimens was not statistically significantly different with gel tubes (3.8 seconds) and the formalin-swirl method (4.5 seconds). Both of these methods, however, were significantly faster than the scalpel-retrieval method (11.2 seconds) (P < .001). The combined radiologist and cytotechnologist time was greatest with the gel tubes (35.1 seconds vs 14.7 and 21.2 seconds, respectively). Core specimens were broken with the formalin-swirl and scalpel-retrieval methods but not with the gel-tube method.

Biopsy, Needle↗
PubMed1997

The breast: in-plane x-ray protection during diagnostic thoracic CT--shielding with bismuth radioprotective garments.

PURPOSE: To evaluate the ability of thin overlying bismuth radioprotective shielding to reduce the x-ray dose to radiosensitive superficial organs during diagnostic computed tomography (CT). MATERIALS AND METHODS: A variety of patient and phantom studies were performed with four thicknesses of bismuth radioprotective latex over the breast. Dose savings were determined with thermoluminescent dosimeters. A prototype and then a final manufactured radioprotective brassiere was constructed and tested for radiation dose savings to the breast during diagnostic chest CT. Preliminary studies were also performed to evaluate shielding of the thyroid, orbit, and testes. RESULTS: The use of bismuth radioprotective latex saved an average 57% of the radiation dose to the breast from thoracic CT, decreasing the radiation level from an average 2.2 rad (0.022 Gy) to 1.0 rad (0.010 Gy) (P < .001). Preliminary tests of shielding other superficial radiosensitive organs frequently included at diagnostic CT (eyes, thyroid gland, and testes) were performed with the same thickness of overlying bismuth radioprotective latex, with similar results. Radiation to the thyroid gland was reduced by 60% (from 0.0573 to 0.0229 Gy) and radiation to the eye and testes was reduced by 40% (from 0.0256 to 0.0154 Gy) and 51% (from 0.0463 to 0.0229 Gy), respectively. CONCLUSION: The use of in-plane overlying bismuth radioprotective latex manufactured into form-fitting garments did not affect the diagnostic CT image but reduced the amount of radiation to radiosensitive superficial structures.

Adult↗
PubMed1996

Analysis of interobserver and intraobserver variability in CT tumor measurements.

OBJECTIVE: The purpose of this study was to evaluate the variability between radiologists interpreting thoracic and abdominal/pelvic CT scans in selecting specific sites of metastatic tumor for measurement (indicator lesions) and to assess interobserver and intraobserver variability in tumor measurement. MATERIALS AND METHODS: Three separate experienced radiologists were asked to review 24 combined thoracic and abdominal CT scans in patients with metastatic tumor. Each radiologist was asked to identify the indicator lesions representative of each patient's tumor bulk. In the second phase of the study, 105 specific foci on 26 combined thoracic and abdominal CT studies (including the original 24) were reviewed twice by the same three radiologists. Up to eight foci were randomly identified per patient, and each observer was asked to determine the slice with the maximum diameter for each tumor focus and to measure it in three dimensions (maximum diameter, its perpendicular, and length). RESULTS: A total of 132 tumor sites were present on the CT studies in phase I, all of which were chosen by at least one observer as an indicator lesion. Of the 116 of these that were separate and nonoverlapped, 57 (49%) were measured by only one observer, whereas 32 (28%) and 27 (23%) were measured by two or all three observers, respectively. Observers were more inclined to pick round or defined/well-defined lesions rather than irregular, oval, or poorly defined ones, although this tendency was not statistically significant. The second phase of the study showed considerable interobserver variability (15%) in CT tumor measurement, which was worse for poorly defined and irregular lesions. Intraobserver variability in measuring individual foci was less (6%). CONCLUSION: Radiologists interpreting thoracic and/or abdominal/pelvic CT scans for metastatic cancer should measure and report a significant number of each patient's tumor sites, especially larger ones in different anatomic areas. When interpreting a follow-up CT scan of a patient with metastatic cancer, the interpreting radiologist should remeasure the indicator lesions on the previous and on the follow-up CT scans, especially when the results will change the patient's treatment response category.

Abdominal Neoplasms↗
PubMed1996

Routine use of a higher order interpolator and bone algorithm in thoracic CT.

OBJECTIVE: This study was designed to evaluate the utility of the routine use of high spatial frequency algorithms and higher order helical interpolators for imaging lung parenchyma during routine thoracic CT. SUBJECTS AND METHODS: We evaluated 50 consecutive patients undergoing clinically indicated thoracic CT using the same imaging parameters and scanner. The helical volume was reconstructed three separate times using standard and higher order (180 degrees linear with double-sided lobes) interpolators and standard and high spatial frequency (bone) algorithms. The images were photographed and given to five separate readers who were kept unaware of the interpolator and algorithm and who were asked to evaluate simultaneously each patient's three sets of images for best, in-between, and worst images of the lung interstitium, pathology, and normal anatomy. RESULTS: All five readers rated the standard interpolator and algorithm images as the worst (p < .01). All five readers consistently rated the double-sided lobe interpolator and bone algorithm images as the best (p < .01). CONCLUSION: A second reconstruction of routine thoracic helical CT data using higher order helical interpolators and a bone algorithm significantly improves interstitial detail of lung parenchyma and overall visualization of normal anatomy and pathologic processes.

Aged↗
PubMed1995

Comparing hospital mortality in adult patients with pneumonia. A case study of statistical methods in a managed care program.

OBJECTIVE: To compare and contrast a managed care program's analysis of differences in hospital mortality with results obtained by accepted statistical methods. DESIGN: A re-analysis of computerized discharge data using the same method used by a managed care program, and using conventional methods of categorical data analysis. One thousand computer simulations of a method for comparing hospitals by severity-adjusted mortality were done to determine the probability of falsely identifying hospitals as high-mortality outliers. SETTING: 22 acute care hospitals in central Pennsylvania. PATIENTS: All adult patients with pneumonia (n = 4587; diagnosis-related groups 089-090) less than 65 years of age who were discharged from the 22 hospitals in 1989, 1990, and 1991, excluding patients with the acquired immunodeficiency syndrome and transplant recipients. MEASUREMENTS: In-hospital mortality adjusted for age and severity of illness using MedisGroups admission severity group score. RESULTS: The hospital that had the highest mortality for adult pneumonia according to the managed care program's analysis did not, according to an appropriate analysis, differ significantly from other area hospitals (likelihood ratio test, P = 0.23). Random variation in this sample of patients with a low average mortality rate (3.5%) showed a 60% chance that 1 or more of the 22 hospitals would be falsely identified as a "high-mortality outlier" when simplistic statistical methods were used. CONCLUSION: Organizations seeking to compare the quality of hospitals and physicians through outcome data need to recognize that simplistic methods applicable to large samples fail when applied to the outcomes of typical patients, such as those admitted for pneumonia. Although these comparisons are much in demand, careful attention must be paid to their statistical methods to ensure validity and fairness.

Adolescent↗
PubMed1995

Fine-needle aspiration biopsy versus fine-needle capillary (nonaspiration) biopsy: in vivo comparison.

PURPOSE: To evaluate, in vivo, the efficacy of fine-needle capillary (nonaspiration) biopsy (FNCB) versus fine-needle aspiration biopsy (FNAB) when performed at the same site with a coaxial technique. MATERIALS AND METHODS: In 91 patients, biopsy was performed at 140 sites in 93 lesions mostly throughout the chest and abdomen with either FNCB or FNAB, or both (98 sites). A coaxial technique with a 22-gauge needle was used. The quality of the specimen was graded by a blinded pathologist, who also made a pathologic diagnosis. RESULTS: No statistically significant difference was noted in the graded criteria performance plus diagnostic yield between the two techniques. When performed before FNAB, FNCB yielded a better quality specimen of a particular site. However, there was no difference in the graded quality of FNAB whether performed before or after FNCB. Insufficient specimens were obtained at 30 (21.4%) of 140 sites with FNCB versus only 18 (12.8%) with FNAB. CONCLUSION: FNCB is an alternative to FNAB and provides a cellular diagnostic specimen from most lesions. When a coaxial method is used and both techniques are employed, the diagnostic accuracy of these techniques is 84%.

Biopsy, Needle↗
PubMed1995

Percutaneous biopsy of the liver and kidney by using coaxial technique: adequacy of the specimen obtained with three different needles in vitro.

OBJECTIVE: The coaxial biopsy technique was evaluated with respect to the quality of specimens obtained from the liver and kidneys in vitro on sequential biopsies at the same site with each of three different biopsy needles. MATERIALS AND METHODS: For each of three different biopsy needles (aspiration 18-gauge Chiba, 18-gauge Sure-Cut, and 18-gauge Biopty), 30 sites (15 liver, 15 kidney) were selected for in vitro coaxial biopsy. At each site, an introducer was placed, through which three sequential biopsies were done. Blinded histopathologic analysis was used to grade the quality of specimens on a scale from 0 (no tissue) to 3 (best) for three criteria: adequacy of tissue for diagnosis, tissue fragmentation, and crush artifact. The overall score was the sum of the scores for the three individual criteria and ranged from 0 (no tissue) to 9 (best). RESULTS: Using an 18-gauge Chiba needle and coaxial technique, we found no significant reduction in specimen quality when we did multiple aspiration biopsies at the same site. However, no tissue was obtained (zero biopsy) from a large number of aspiration biopsies done with the Chiba needle, ranging from 24 of 30 for the first biopsy to 17 of 30 for the third biopsy. Specimen quality was reduced somewhat between the first and third biopsies when the 18-gauge Sure-Cut and Biopty needles were used. With the Sure-Cut needle, this reduction in quality was significant (p = .009) and was primarily related to increased tissue fragmentation and crushing. The reduction in quality with multiple biopsy attempts was less severe with the Biopty needle/gun. Although the mean score decreased from 6.6 for the first biopsy to 5.5 for the third biopsy, this reduction was not significant (p = .06). In addition, the Biopty gun, unlike the other two needles, had few zero biopsies. CONCLUSION: The use of a coaxial technique with an 18-gauge Biopty needle enables collection of a large amount of high-quality tissue for histopathologic analysis with a minimum number of failed biopsies as compared with the 18-gauge Chiba needle and the 18-gauge Sure-Cut needle.

Biopsy, Needle↗
PubMed1995

Informed consent forms for clinical and research imaging procedures: how much do patients understand?

OBJECTIVE: Informed consent is often obtained in diagnostic radiology, especially for invasive procedures and research studies. However, how much the average patient actually understands of the information contained in these informed consent forms is uncertain. A cross section of the clinical and research consent forms used in diagnostic radiology was evaluated with respect to their readability, that is, how easy or difficult they were to understand. MATERIALS AND METHODS: The active members of the Association of University Radiologists were solicited to provide copies of their clinical and research informed consent forms. After eliminating duplicates, we digitized the forms and used a computer program to evaluate their readability. Computer readability assessment allows the rapid study of an entire document by a variety of readability formulas (Flesch-Kincaid, Flesch, and Fog). RESULTS: We received 549 different consent forms from 156 institutions; 265 forms were intended primarily for clinical use and 284 were used primarily for research. Although the clinical consent forms were only 41% as long as those for research, a statistical comparison showed them to be harder to understand (p < 0.005). The mean readability score (years of education needed to understand) for all 265 clinical consent forms was 15 versus 12 for the research forms. The most complex clinical consent forms were those written by hospitals for any type of procedure or operation (the generic surgical or procedure consent form). On average, this type of clinical consent form required at least a college education to understand. CONCLUSION: Our results show that most consent forms used in radiology practice are too complex for the average patient to understand. The increased complexity of clinical consent forms, especially the generic surgical or procedure consent forms, as compared with research consent forms, is probably a product of the decreased attention given to the clinical consent forms, the bureaucratic and legal requirements of the clinical forms, and the lack of physician participation in preparing these forms.

Cognition↗
PubMed1995

Reconstructed helical CT scans: improvement in z-axis resolution compared with overlapped and nonoverlapped conventional CT scans.

OBJECTIVE: This in vitro study was designed to assess the z-axis resolving capabilities of reconstructed helical CT scans obtained with various imaging parameters versus those of conventional CT scans and the effect of decreasing slice index on the z-axis resolution of helical CT. MATERIALS AND METHODS: A z-axis line-pair phantom was imaged using conventional nonoverlapped CT scans, conventional CT scans that overlapped by 50%, and helical CT scans with pitches of 1.0 and 1.5. All helical images were reconstructed at comparable slice indexes (image indexes of 2.0, 1.0, and 0.5 mm for pitch = 1.0, and image indexes of 3.0, 1.5, and 0.75 mm for pitch = 1.5). Midline coronal and sagittal reconstructed images were obtained to allow standardized visualization of line pairs. The reconstructed images were reviewed separately by 10 radiologists. RESULTS: The overall z-axis resolution of reconstructed helical CT scans equaled or exceeded that of nonoverlapped conventional CT scans in all cases and equaled that of 50% overlapped conventional CT scans in 75% of cases. The 1.0-pitch helical sequences showed improved z-axis resolution with decreasing slice index. No statistically significant improvement in z-axis resolution could be determined by the observers for 1.5-pitch sequences with decreasing slice index. CONCLUSION: The use of helical CT with a pitch of 1.0 or 1.5 and an increased slice index can improve the z-axis resolution of reconstructed images when compared with nonoverlapped conventional CT and frequently equals the resolution of 50% overlapped conventional CT. This improvement in z-axis resolution should improve the appearance of reconstructed images (as used in CT angiography and three-dimensional imaging) by reducing partial volume artifacts while affording faster scanning at a reduced skin-surface radiation dose.

Humans↗