Biomedical subjects

Jayawant N Mandrekar

Publications and source records attributed to Jayawant N Mandrekar.

26 records · Page 2Linked to original sources

PubMed2005

Agreement between patient reports of cardiovascular disease and patient medical records.

OBJECTIVE: To determine how well patient-reported cardiovascular disease (CVD) and CVD risk factor information agrees with medical record information. METHODS: Information from Patient/Family History (PFH) questionnaires completed between 1996 and 1999 by residents of Olmsted County, Minnesota, aged 20 years and older was compared with information available through the Mayo Clinic medical diagnostic index. Positive and negative agreement values were calculated by comparing agreement between the 2 data sources. Also, with the Mayo Medical Index serving as the criterion standard, sensitivity, specificity, and positive and negative predictive values of questionnaire information were calculated overall and by subgroups of sex, age, and years of education. RESULTS: Questionnaire responses were retrieved for 26,162 patients. Positive agreement values ranged from 31% for report of a medical problem or surgery related to arteries to the head, arms, or legs or the aorta to 78% for high blood pressure. Negative agreement values ranged from 90% for high cholesterol to 98% for medical problem or surgery related to arteries to the head, arms, or legs or the aorta. Sensitivity of questionnaire information ranged from 37% to 73%, whereas positive predictive values ranged from 27% to 86%. Positive agreement, sensitivity, and positive predictive values tended to increase with increasing age of the patient. Specificity and negative predictive values were 87% or greater, and negative agreement, specificity, and negative predictive values decreased with increasing age. CONCLUSION: Positive patient reports of CVD conditions and risk factors are relatively inaccurate. However, negative self-reports of these conditions are unlikely to be noted in the medical record. Further development of the PFH questionnaire is necessary to ensure accurate patient reporting of CVD data.

Adult↗

PubMed2005

Can neck size in elastase-induced aneurysms be controlled? A prospective study.

BACKGROUND AND PURPOSE: An earlier retrospective study indicated that the neck size of elastase-induced aneurysms could be controlled by adjusting the position of the inflated balloon. We report the current prospective study to confirm our previous work. METHODS: Ninety elastase-induced aneurysms were created in rabbits. Group 1 (n = 62) included cases in which the occlusion balloon resided low, completely within the brachiocephalic/subclavian arteries. Group 2 (n = 28) included cases in which the balloon resided high, within both the common carotid artery and brachiocephalic/subclavian arteries. Follow-up digital subtraction angiography was performed. The aneurysm sizes were measured and compared between groups. The Student t test and the Fisher exact test were used for statistical analysis. RESULTS: The mean aneurysm neck diameter and width for group 1 was significantly larger than that of group 2 (3.4 +/- 1.2 and 2.3 +/- 0.9 mm, P < .001; 3.8 +/- 1.0 and 3.3 +/- 0.9 mm, P < .05, respectively). The proportion of wide-necked aneurysms in group 1 was significantly larger than that in group 2 (29% vs 4%; P < .005). Mean dome-to-neck ratios were 1.2 +/- 0.4 and 1.7 +/- 0.7 for groups 1 and 2 (P < .005). There was no significant difference in aneurysm height between groups 1 and 2 (8.0 +/- 1.7 and 7.5 +/- 2.2 mm; P > .05). CONCLUSION: The neck size of elastase-induced aneurysm models in rabbits can be controlled by adjusting the position of the inflated balloon.

Angiography, Digital Subtraction↗

PubMed2004

A comparison of clinical teaching evaluations by resident and peer physicians.

The purpose of this study was to compare the reliability of inpatient teaching evaluations by resident and peer physicians on Mayo internal medicine hospital services. Three resident and three peer evaluators observed 10 consecutively chosen attending physicians on the Mayo hospital services. Evaluations by resident and peer physicians were compared in terms of mean scores. Kendall's coefficient of concordance (KCC) was used to summarize inter-rater reliabilities and Cronbach's coefficient alpha was used to determine internal consistencies of evaluations by residents and peers. Results of this study revealed that mean scores of the 13 evaluation items were generally higher for resident than peer physicians. None of the items completed by residents had KCC scores >0.5, whereas 10 of the items completed by peers had KCC scores >0.5. Likewise, none of the residents' items had KCC p-values <0.05, whereas nine of the peers' items had KCC p-values <0.05. The overall internal consistency was higher for peers (alpha = 0.76) than for residents (alpha = 0.71). In conclusion, resident physicians uniformly rate faculty highly. Furthermore, peer evaluations yield higher inter-rater and internal reliabilities than resident evaluations, indicating that peer physicians are more reliable than residents for assessing bedside teaching.

Educational Measurement↗

PubMed2004

How reliable are assessments of clinical teaching? A review of the published instruments.

BACKGROUND: Learner feedback is the primary method for evaluating clinical faculty, despite few existing standards for measuring learner assessments. OBJECTIVE: To review the published literature on instruments for evaluating clinical teachers and to summarize themes that will aid in developing universally appealing tools. DESIGN: Searching 5 electronic databases revealed over 330 articles. Excluded were reviews, editorials, and qualitative studies. Twenty-one articles describing instruments designed for evaluating clinical faculty by learners were found. Three investigators studied these papers and tabulated characteristics of the learning environments and validation methods. Salient themes among the evaluation studies were determined. MAIN RESULTS: Many studies combined evaluations from both outpatient and inpatient settings and some authors combined evaluations from different learner levels. Wide ranges in numbers of teachers, evaluators, evaluations, and scale items were observed. The most frequently encountered statistical methods were factor analysis and determining internal consistency reliability with Cronbach's alpha. Less common methods were the use of test-retest reliability, interrater reliability, and convergent validity between validated instruments. Fourteen domains of teaching were identified and the most frequently studied domains were interpersonal and clinical-teaching skills. CONCLUSIONS: Characteristics of teacher evaluations vary between educational settings and between different learner levels, indicating that future studies should utilize more narrowly defined study populations. A variety of validation methods including temporal stability, interrater reliability, and convergent validity should be considered. Finally, existing data support the validation of instruments comprised solely of interpersonal and clinical-teaching domains.

Academic Medical Centers↗

PubMed2004

Impact of FUTON and NAA bias on visibility of research.

OBJECTIVE: To determine whether availability of journals on MEDLINE as FUTON (full text on the Net) affects their impact factor. MATERIAL AND METHODS: A comprehensive search identified 324 cardiology, nephrology, and rheumatology/immunology journals on-line until May 2003. The status of these journals was ascertained in MEDLINE as having FUTON, abstracts only, and NAA (no abstract available). Impact factors for all available journals from the Institute for Scientific Information (ISI) were abstracted. RESULTS: Of the 324 Journals, 124 (38.3%) were FUTON, 138 (42.6%) had abstracts only, and 62 (19.1%) had NAA. The mean (+/-SEM) impact factor was 3.24 (+/-0.32), 1.64 (+/-0.30), and 0.14 (+/-0.45), respectively. Of the 324 current journals, 159 existed in both the pre- and the post-Internet era. An analysis of the change (ie, delta) in impact factor from the pre- to post-Internet era revealed a trend between journals with FUTON and abstracts only (P=.17, Wilcoxon rank sum test). Similar analyses of the delta of cardiology journals revealed a statistically significant difference between Journals with FUTON and abstracts only (P=.04, Wilcoxon rank sum test). CONCLUSION: FUTON bias is the tendency to peruse what is more readily available. This is the first study to show that on-line availability of medical literature may increase the impact factor and that such increase tends to be greater in FUTON journals. Failure to consider this bias may affect a journal's impact factor. Also, it could limit consideration of medical literature by ignoring relevant NAA articles and thereby influence medical education akin to publication or language bias.

Abstracting and Indexing↗

PubMed2003

Are our data symmetric?

Skewness indicates a lack of symmetry in a distribution. Knowing the symmetry of the underlying data is essential for parametric analysis, fitting distributions or doing transformations to the data. The coefficient of skewness is the commonly used measure to identify a lack of symmetry in the underlying data, although graphical procedures can also be effective. We discuss three different methods to assess skewness: traditional coefficient of skewness index, skewness index based on the L-moments discussed by Hosking and the asymptotic test of symmetry developed by Randles et al. With this work, we provide easy-to-implement S-PLUS functions as well as discuss the advantages and shortcomings of each technique.

Biometry↗

PubMedDate not supplied

Assessment of wall shear stress changes in arteries and veins of arteriovenous polytetrafluoroethylene grafts using magnetic resonance imaging.

The purpose of the study was to determine simultaneously the temporal changes in luminal vessel area, blood flow, and wall shear stress (WSS) in both the anastomosed artery (AA) and vein (AV) of arteriovenous polytetrafluoroethylene (PTFE) grafts. PTFE grafts were placed from the iliac artery to the ipsilateral iliac vein in 12 castrated juvenile male pigs. Contrast-enhanced magnetic resonance angiography with cine phase-contrast magnetic resonance imaging was performed. Luminal vessel area, blood flow, and WSS in the aorta, AA, AV, and inferior vena cava were determined at 3 days (D3), 7 days (D7), and 14 days (D14) after graft placement. Elastin von Gieson staining of the AV was performed. The average WSS of the AA was highest at D3 and then decreased by D7 and D14. In contrast, the average WSS and intima-to-media ratio of the AV increased from D3 to D7 and peaked by D14. Similarly, the average area of the AA was highest by D7 and began to approximate the control artery by D14. The average area of the AV had decreased to its lowest by D7. High blood flows through the AA causes a decrease in average WSS and increase in the average luminal vessel area, whereas at the AV, the average WSS and intima-to-media ratio both increase while the average luminal vessel area decreases.

Animals↗

PubMedDate not supplied

Acupuncture for hot flashes: a randomized, sham-controlled clinical study.

OBJECTIVE: Hot flashes are a significant problem in women going through the menopausal transition that can substantially affect quality of life. The world of estrogen therapy has been thrown into turmoil with the recent results of the Women's Health Initiative trial report. Pursuant to a growing interest in the use of alternative therapies to alleviate menopausal symptoms and a few pilot trials that suggested that acupuncture could modestly alleviate hot flashes, a prospective, randomized, single-blind, sham-controlled clinical trial was conducted in women experiencing hot flashes. DESIGN: Participants, after being randomized to medical versus sham acupuncture, received biweekly treatments for 5 weeks after a baseline assessment week. They were then followed for an additional 7 weeks. Participants completed daily hot flash questionnaires, which formed the basis for analysis. RESULTS: A total of 103 participants were randomized to medical or sham acupuncture. At week 6 the percentage of residual hot flashes was 60% in the medical acupuncture group and 62% in the sham acupuncture group. At week 12, the percentage of residual hot flashes was 73% in the medical acupuncture group and 55% in the sham acupuncture group. Participants reported no adverse effects related to the treatments. CONCLUSIONS: The results of this study suggest that the used medical acupuncture was not any more effective for reducing hot flashes than was the chosen sham acupuncture.

Acupuncture Therapy↗