Engineering topological states in atom-based semiconductor quantum dots.

The realization of controllable fermionic quantum systems via quantum simulation is instrumental for exploring many of the most intriguing effects in condensed-matter physics1-3. Semiconductor quantum dots are particularly promising for quantum simulation as they can be engineered to achieve strong quantum correlations. However, although simulation of the Fermi-Hubbard model4 and Nagaoka ferromagnetism5 have been reported before, the simplest one-dimensional model of strongly correlated topological matter, the many-body Su-Schrieffer-Heeger (SSH) model6-11, has so far remained elusive-mostly owing to the challenge of precisely engineering long-range interactions between electrons to reproduce the chosen Hamiltonian. Here we show that for precision-placed atoms in silicon with strong Coulomb confinement, we can engineer a minimum of six all-epitaxial in-plane gates to tune the energy levels across a linear array of ten quantum dots to realize both the trivial and the topological phases of the many-body SSH model. The strong on-site energies (about 25 millielectronvolts) and the ability to engineer gates with subnanometre precision in a unique staggered design allow us to tune the ratio between intercell and intracell electron transport to observe clear signatures of a topological phase with two conductance peaks at quarter-filling, compared with the ten conductance peaks of the trivial phase. The demonstration of the SSH model in a fermionic system isomorphic to qubits showcases our highly controllable quantum system and its usefulness for future simulations of strongly interacting electrons.

Alcohol, drug misuse and suicide attempts: unrecognised causes of out of hospital cardiac arrests admitted to intensive care units.

AIM: To assess the contribution of alcohol, drug abuse and suicide attempts to out of hospital cardiac arrests (OHCA) who are admitted to our intensive care unit (ICU). METHODS: Retrospective review of all OHCA admitted to the ICU over a 2-year period. RESULTS: There were 26 OHCA. Six patients survived, all of whom had a cardiac aetiology for their arrest. Ten patients arrested due to external factors (drug misuse n = 4, alcohol excess n = 1, suicide attempts n = 4 and accidental choking n = 1). All of the patients who arrested secondary to external factors were young (37.2 +/- 13.58 years), 90% were male and all died in hospital. All of the cases of drug misuse involved cocaine. CONCLUSION: Alcohol, drug misuse and suicide attempts contribute significantly to the number of OHCA which are admitted to ICU. Moreover, cocaine usage has contributed to a number of OHCA in our study.

Determinants of competency judgments by experienced laparoscopic surgeons.

BACKGROUND: The definitive criteria for assessing competence remain elusive. In our study, we aimed to identify the determinants of competence assessment used by individual laparoscopic surgeons. METHODS: In a blinded fashion, five laparoscopic surgeons rated 27 subjects on three laparoscopic simulations in four skill categories: clinical judgment, dexterity, serial/simultaneous complexity, and spatial orientation. The raters then assessed overall subject competence for each procedure. Point-biserial correlational analyses and cluster analyses were performed to ascertain the relationships among the various scales. RESULTS: All of the correlations between the skills' ratings and competence judgments were statistically significant ( p <.05). No skill rating was consistently more highly correlated with the competence rating. There were no distinct patterns of correlations for each rater or each procedure. One factor emerged from each cluster analysis of the skills measures. CONCLUSIONS: The results suggest that the four skills scored in the study are highly correlated with each other and are important in determining competence. The cluster analyses revealed that the surgeon raters shared a common perception of competence.

Evaluating minimally invasive surgery training using low-cost mechanical simulations.

BACKGROUND: The goal of this study was to develop, test, and validate the efficacy of inexpensive mechanical minimally invasive surgery (MIS) model simulations for training faculty, residents, and medical students. We sought to demonstrate that trained and experienced MIS surgeon raters could reliably rate the MIS skills acquired during these simulations. METHODS: We developed three renewable models that represent difficult or challenging segments of laparoscopic procedures; laparoscopic appendectomy (LA), laparoscopic cholecystectomy (LC), and laparoscopic inguinal hernia (LH). We videotaped 10 students, 12 surgical residents, and 1 surgeon receiving training on each of the models and again during their posttraining evaluation session. Five MIS surgeons then assessed the evaluation session performance. For each simulation, we asked them to rate overall competence (COM) and four skills: clinical judgment (respect for tissue) (CJ), dexterity (economy of movement) (DEX), serial/simultaneous complexity (SSC), and spatial orientation (SO). We computed intraclass correlation (ICC) coefficients to determine the extent of agreement (i.e., reliability) among ratings. RESULTS: We obtained ICC values of 0.74, 0.84, and 0.81 for COM ratings on LH, LC, and LA, respectively. We also obtained the following ICC values for the same three models: CJ, 0.75, 0.83, and 0.89; DEX, 0.88, 0.86, and 0.89; SSC, 0.82, 0.82, and 0.82; and SO, 0.86, 0.86, and 0.87, respectively. CONCLUSIONS: We obtained very high reliability of performance ratings for competence and surgical skills using a mechanical simulator. Typically, faculty evaluations of residents in the operating room are much less reliable. In contrast, when faculty members observe residents in a controlled, standardized environment, their ratings can be very reliable.

Ventilator-patient dyssynchrony induced by change in ventilation mode.

Patient-ventilator interactions may be coordinated (synchronous) or uncoordinated (dyssynchronous). Ventilator-patient dyssynchrony increases the work of breathing by imposing a respiratory muscle workload. Respiratory centre output responds to feedback from respiratory muscle loading. Mismatching of respiratory centre output and mechanical assistance results in dyssynchrony. We describe a case of severe patient-ventilator dyssynchrony and hypothesize that dyssynchrony was induced by a change in mode of ventilation from pressure-cycled to volume-cycled ventilation, due to both ventilator settings and by the patient's own respiratory centre adaptation to mechanical ventilation. The causes, management and clinical implications of dyssynchrony are discussed.

A multidimensional approach to breast cancer education.

BACKGROUND: This study was undertaken to present a multidimensional breast cancer education package (BCEP) to medical students in an effort to improve breast cancer education. METHODS: The students were exposed to a four-part BCEP consisting of a hands-on structured clinical instruction module (SCIM), a lecture, a problem-based learning (PBL) small-group discussion, and a written manual. Each component was evaluated with a questionnaire. Students responded to the items using a five-point Likert scale ranging from 1 (strongly disagree) to 5 (strongly agree). RESULTS: The mean overall evaluations for the BCEP components were: SCIM, 4.6; lecture, 4.0; manual 3.8, and PBL discussion, 3.6. Highly rated qualities of the SCIM included organization (4.7), faculty preparedness (4.8), and opportunity to practice skills (4.5). The students agreed that the lecture (4.1), manual (3.8), and PBL discussion (4.2) had prepared them for the SCIM. CONCLUSION: This innovative BCEP effectively improved students' understanding of breast cancer.

Need for comprehensive women's health continuing medical education among primary care physicians.

BACKGROUND: The Council on Graduate Medical Education's (COGME) Fifth Report on Women and Medicine states that "changes in undergraduate and graduate medical education, in addition to continuing medical education, are needed to address adequately the comprehensive health needs of women." Primary care physicians (PCPs) who completed residency training prior to the establishment of new guidelines for women's health education are dependent on continuing medical education (CME) to update their knowledge and skills. METHODS: Primary care physicians attending a university-based CME program in family medicine were surveyed (n = 300) about their need for CME in women's health topics. Responses were analyzed using chi-square analysis and Pearson correlations. Topics of interest were compared with women's health competencies published in 1997 by the American Board of Internal Medicine (ABIM) and in 1997 by the American Academy of Family Physicians (AAFP). RESULTS: Of 30 women's health topics listed, 22 were of interest to 50% or more of respondents and 11 were of very high interest (p < .05). Respondents most interested in women's health CME were most likely to believe CME would reduce the number of referrals currently required to evaluate women's breast problems. Topics of interest also align well with ABIM and AAFP competencies in women's health. CME in comprehensive women's health care is therefore of high interest to our respondents and topics of greatest interest are identified. IMPLICATIONS: Areas of interest correlate well with new requirements by ABIM and AAFP and should be targeted by CME programs.

The relative contributions of interpersonal and specific clinical skills to the perception of global clinical competence.

BACKGROUND: The objective structured clinical examination (OSCE), an established instrument for evaluating resident competence, was used to test the hypothesis that faculty assessment of clinical competence in residents at various levels of training may be influenced more by general skills as a physician and less by competency in the actual skills being specifically tested. In this study, advantage was taken of the anticipated observation that general surgery residents did not demonstrate improvement in their ability to perform a focused neurological assessment over time. METHODS: An OSCE, which was administered to 56 general surgery residents at all levels of training, included the assessment of a specific clinical neurosurgical problem (sciatica). Univariate and multivariate analyses were used to evaluate the relationship between the global faculty judgment of competent or noncompetent and the other performance measures that were applied. RESULTS: At different levels of training, there was no observed difference in the specific skills being tested; nevertheless, junior and senior residents were more likely than incoming interns to be judged "competent" and received better evaluations of how well they introduced themselves to the patient. The competence judgment correlated significantly with all of the other performance measures, including the skills being tested. CONCLUSIONS: The perception of competence is not solely dependent upon the particular skills under scrutiny. General competence does not guarantee competence in each specific skill set of a medical specialty.

Interpreting the judgment of surgical faculty regarding resident competence.

BACKGROUND: It is reasonable to propose that competence is a multifaceted characteristic defined in part by some minimum level of knowledge and skill. In this study we examined the relationship between surgical faculty's judgment of clinical competence, as measured by a surgical resident objective structured clinical examination (OSCE), and the residents' objective performance on the skills being tested. METHODS: Fifty-six general surgery residents at all levels of training participated in a 30-station OSCE. At the completion of each station, the faculty proctor made several overall judgments regarding each resident's performance, including a global judgment of competent or not competent. The competence judgment was applied to the objective percentage performance score in three different ways to construct methods for determining competence based solely upon this objective percentage score. RESULTS: The average mean competent score (MCS) across the stations was 61%, and the average mean noncompetent score (MNCS) was 38%. The difference between MCS and MNCS for each station was very consistent. Upper threshold scores above which a judgment of competent was always made, and lower threshold scores below which a judgment of noncompetent was always made were observed. Overall, the average mean and threshold scores for competent and noncompetent groups were remarkably similar. For performance scores in the range between the threshold competent and noncompetent scores at each station, measures other than objective performance on the skills being evaluated determined the judgment of competent or not competent. CONCLUSIONS: Empirically determined minimum acceptable standards for objective performance in clinical skills and knowledge appeared to have been subconsciously applied to the competence judgment by the faculty evaluators in this study. Other factors appeared to have become determinate when the objective performance score fell within a range of uncertainty.

Assessing residents' clinical performance: cumulative results of a four-year study with the Objective Structured Clinical Examination.

BACKGROUND: The Objective Structural Clinical Examination (OSCE) is an objective method for assessing clinical skills and can be used to identify deficits in clinical skill. During the past 5 years, we have administered 4 OSCEs to all general surgery residents and interns. METHODS: Two OSCEs (1993 and 1994) were used as broad-based examinations of the core areas of general surgery; subsequent OSCEs (1995 and 1997) were used as needs assessments. For each year, the reliability of the entire examination was calculated with Cronbach's alpha. A reliability-based minimal competence score (MCS) was defined as the mean performance (in percent) minus the standard error of measurement for each group in 1997 (interns, junior residents, and senior residents). RESULTS: The reliability of each OSCE was acceptable, ranging from 0.63 to 0.91. The MCS during the 4-year period ranged from 45% to 65%. In 1997, 4 interns, 2 junior residents, and 2 senior residents scored below their group's MCS. MCS for the groups increased across training levels in developmental fashion (P < .05). CONCLUSIONS: Given the relatively stable findings observed, we conclude (1) the OSCE can be used to identify group and individual differences reliably in clinical skills, and (2) we continue to use this method to develop appropriate curricular remediation for deficits in both individuals and groups.

Critical assessment of the head and neck clinical skills of general surgery residents.

Head and neck surgery is an important part of general surgery. There is, however, little information about the quality of residents' clinical skills in this important field. In an Objective Structured Clinical Examination (OSCE), residents encounter multiple patients with various clinical problems and are rated by faculty members using objective criteria. This study was undertaken to assess the head and neck surgery skills of a group of general surgical residents. Fifty-one general surgery residents examined the same nine patients with head and neck disease. Faculty members graded each clinical interaction according to preset objective criteria. Both actual (e.g., thyroid nodule, oral cancer follow-up examination) and simulated (e.g., dysphagia) patients were used in the OSCE. The reliability of the examination was assessed by coefficient alpha. The construct validity was determined by a two-way analysis of variance with one repeated measure. The reliability was 0.75 for the clinical examination. Performance varied by level of training: Residents performed at a higher level than interns (p < 0.0001), but overall scores were poor (mean score 55%). Important deficits in skills were identified at all levels of training. It is concluded that more attention should be focused on specific outcome assessments of surgical training programs and on strategies for upgrading the clinical skills of surgical residents.

The reliability of six faculty members in identifying important OSCE items.

PURPOSE: To measure the agreement among faculty members about the importance of items on a checklist used to grade an objective structured clinical examination (OSCE) station. METHODS: Six faculty members rated the importance of 47 items for an OSCE station in which students took the history of a patient with sore throat and hoarseness. RESULTS: Of the 47 items, the raters independently identified 15 items as very important. The reliability of each individual rater was fair (averaged value of alpha = .63.) The reliability of the mean rating of the six raters was high (alpha = .91). CONCLUSIONS: The results strongly suggest that when a group of faculty members cooperatively identifies the important items to be included in an OSCE checklist, the reliability of the checklist is superior to one created by a single author.

Late-onset preemptive analgesia associated with preincisional large-dose alfentanil.

UNLABELLED: Few studies using systemic opioids have been adequately designed to demonstrate a preemptive effect. We investigated the preemptive effect of intraoperative large-dose intravenous (I.V.) opioids over a 72-h period after lower abdominal surgery. Thirty-eight ASA physical status I or II patients undergoing abdominal hysterectomy were studied in a prospective, randomized, double-blind design. Group PRE received alfentanil 70 microg/kg over 10 min before surgical incision; Group POST received alfentanil 70 microg/kg over 10 min after incision. Patients received no other intraoperative opioid. Pain was treated in the recovery room with 2-mg I.V. boluses of morphine and was subsequently managed via patient-controlled analgesia (PCA) using morphine sulfate. Visual analog scale pain scores at rest (VAS-R) and on movement (VAS-M) and PCA morphine consumption were recorded for 72 hours. VAS-M and VAS-R scores did not differ at any point, and morphine consumption was similar in both groups over the initial 48 h. Group PRE used significantly less morphine from 48 to 72 h postoperatively (P < 0.02). We conclude that presurgical incisional (i.e., compared with postincisional) large-dose opioid exposure results in a modest, late decrease in postoperative morphine consumption, with no clinical impact on early postoperative pain. Timing of the observed reduction coincides with maximal output of substances implicated in experimental hyperalgesia. IMPLICATIONS: When given before surgical incision, alfentanil, a short-acting narcotic, was associated with a reduction in morphine requirements 48-72 h after surgery. Brief interventions may have a delayed and sustained impact on pain perception, possibly by reducing mechanisms of sensitization.

Cancer pain education among family physicians.

This study used performance-based testing (objective structured clinical evaluation, OSCE) to evaluate the skills of family physicians in assessing and managing the severe pain of a cancer patient, and evaluated a new method of education about the management of cancer pain. Twenty-four primary care physicians completed a detailed pain assessment of the same standardized cancer pain patient (Part A). A proctor observed the interviews and rated the physicians on a variety of pre-determined items believed to be important for pain assessment. The physicians were then allowed 5 min to answer management questions about the patient's cancer pain (Part B). After reviewing each physician's performance on Parts A and B, the proctor provided immediate feedback and instruction (Part C) on basic principles of cancer pain assessment and management. On average, the primary care physicians asked 52% (+/-4.5%) of the indicated questions of a detailed pain assessment. Performance was poorest in asking about previous pain history, temporal pattern of pain, and pain intensity. Performance on the pain assessment was best for eliciting pain location and pain-relieving factors. Primary care physicians obtained mean scores of 36% (+/-3%) on Part B of the OSCE. Although opioid therapy was frequently prescribed, only 42% of prescriptions were for regular administration. Performance on Parts A and B correlated poorly with years in practice, and older physicians tended to perform a less detailed pain assessment than their younger colleagues. Most physicians enjoyed participating in this instructional formal and believed that the proctor feedback increased the educational value of the module. The results of our study suggest that many family physicians may be inadequate in their clinical assessment and management of cancer pain. Our study supports the need for continuing education in cancer pain management, regardless of years in practice. Further study should evaluate the effects of different educational programs on clinical practice in patient care.

Improving residents' clinical skills with the structured clinical instruction module for breast cancer: results of a multiinstitutional study. Breast Cancer Education Working Group.

BACKGROUND: The purpose of this study was to determine, in a multiinstitutional setting, the effectiveness of the structured clinical instruction module (SCIM) as an instructional format for surgical residents. METHODS: The breast cancer SCIM is an abbreviated (3-hour) clinical skills course that places residents in realistic clinical settings. The curriculum encompasses all aspects of breast cancer patient assessment. The SCIM was administered to 137 residents at five institutions. Sixty-six faculty members and 52 patients participated. All participants were surveyed with multiitem questionnaires. The residents were also asked to perform a self-assessment of their skills before and after the SCIM. RESULTS: The SCIM was delivered at all institutions without difficulty. All participants rated the SCIM highly (from "above average" to "outstanding"). Mean ratings (on a 5-point scale) for the overall effectiveness of the SCIM as an educational format follow: [table: see text] The pretest mean (on a 5-point scale) on the self-assessment was 2.46 ("less than competent"); the posttest mean was 3.54 ("more than competent") (p < 0.0001). CONCLUSIONS: Residents are acutely aware of their deficiencies in understanding breast cancer. The SCIM is a standardized, reproducible, portable, and effective educational vehicle.

Residents' evaluation of a problem-based learning curriculum in a general surgery residency program.

METHODS: To determine residents' satisfaction with problem-based learning and its tutors, to determine how residents prepare for sessions, and to identify the characteristics of both effective sessions and tutors, we analyzed 132 evaluations from 24 residents who completed 1 or more of the 9 cases presented during the first 9 months of our program. The 38-item evaluation questionnaire asked residents to rate tutor characteristics, various aspects of the sessions, and methods used to prepare for the sessions. RESULTS: Residents were well satisfied with the problem-based learning sessions and with the logistics of our program; they found the overall quality of the tutor more important than that of the case; they valued an active, thought-provoking tutor more than a traditional facilitator; and they most often used standard textbooks to prepare for the sessions. CONCLUSIONS: Problem-based learning is a practical, enjoyable graduate curricular vehicle when implemented with well-written cases and active tutors.

Ward evaluations: should they be abandoned?

Even in the era of the objective structured clinical examination (OSCE), the predominant method of resident evaluation is the faculty ward evaluation (WE), despite many concerns about its reliability. The aim of this study was to determine the value of the WE as a measurement of clinical competence in terms of both reliability and validity. In a one-year period, surgery faculty members evaluated 72 residents. An average of 7 faculty members evaluated each resident. The evaluation form contained 10 specific performance ratings and an overall evaluation. Inter-rater reliability of the overall performance ratings was calculated by using the intraclass correlation. Validity of the WE was evaluated in four ways. Inter-rater reliability of the overall performance rating was 0.82; the reliability of a single overall rating was 0.39. (1) A discriminant function analysis indicated that residents at advanced levels of training received more positive evaluations than residents at less advanced levels (P < 0.0001). (2) The overall rating was significantly correlated (r = 0.55, P < 0.0001) with the overall score of a concurrent OSCE. (3) A factor analysis showed high correlations among the items, indicating a lack of discrimination between the skills. (4) Overall ratings were insensitive to performance deficiencies. Only 1.3% of the ratings were unsatisfactory or marginal. The WE was sufficiently reliable to estimate the faculty's view of each resident. The fact that the ratings tended to differentiate residents by level of training and that ratings significantly correlated with the OSCE provides strong evidence of their validity. However, factor analysis indicated that the faculty members were making one global, undifferentiated judgment and that these ratings did not identify deficient performance skills. We conclude that ward evaluations have a place in the assessment of residents.

The multidisciplinary structured clinical instruction module as a vehicle for cancer education.

BACKGROUND: The Structured Clinical Instruction Module (SCIM) modifies the Objective Structured Clinical Examination (OSCE) for teaching purposes. This study determined the effectiveness of a breast cancer SCIM in enhancing residents' clinical skills. METHODS: Twenty-five residents, 15 faculty members, and 12 breast cancer patients (simulated and actual) participated in the multistation, multidisciplinary SCIM. Afterward, faculty members, residents, and patients evaluated the SCIM. Residents completed an 18-item self-assessment of their skills before and after the SCIM. RESULTS: All residents, faculty members, and patients rated the SCIM as either outstanding or above average as an educational experience. The residents' self-assessments of their skills were significantly higher after the SCIM than before. CONCLUSIONS: This study shows that residents are aware of their deficiencies in breast cancer management. The SCIM provides an excellent format for residents to improve their clinical skills.

The structured clinical instruction module as a tool for improving students' understanding of breast cancer.

The Structured Clinical Instruction Module (SCIM) is a novel format for teaching clinical skills. A multidisciplinary SCIM was presented to 30 medical students to improve their understanding of breast cancer. The SCIM consisted of 12 10-minute stations, each covering a different aspect of the diagnosis and management of breast cancer (e.g., history, physical examination, treatment options, mammography, cytology, and pathology). The students rotated through the various stations in groups of three. Nine patients and 14 faculty members participated. At the end of the SCIM, students, faculty, and patients rated their level of agreement (on a five-point scale ranging from "Strongly Disagree" to "Strongly Agree") with statements on a multi-item evaluation questionnaire. All ratings were positive. The students agreed most that the small-group format was an effective instructional method (mean, 4.6). Both students and faculty agreed that the SCIM increased students' clinical skills (mean, 4.4 in both evaluations). Faculty expressed a willingness to participate in future such workshops (mean, 4.6). Patients agreed most strongly that they enjoyed the SCIM (mean, 5.0) and that faculty feedback to students was excellent (mean, 5.0). The SCIM was well received by all participants in this pilot project.