PubMed Health⌕ Search

Biomedical subjects

Lawrence Smith

Publications and source records attributed to Lawrence Smith.

11 recordsLinked to original sources
PubMed2006

Sleep-disordered breathing and blood pressure levels among shift and day workers.

BACKGROUND: Sleep-disordered breathing (SDB) can be one of the major determinants of high blood pressure (BP), but there has been no study on SDB with an emphasis on shift workers. The objective of this study was to examine whether a relationship between SDB and blood pressure/hypertension is more evident among shift workers than among day workers. METHODS: In this cross-sectional study, we measured BP levels and oxygen desaturation index (by nocturnal pulse oximetry) among 253 male shift workers and 206 male day workers aged 30 to 62 years at nuclear power plants in Japan. RESULTS: The prevalence of SDB (3% oxygen desaturation index >or=10 and >or=15 per hour) in all subjects was 11.3% (95% confidence interval [95% CI] 8.4-14.2) and 6.1% (95% CI 3.9-8.3), respectively, with no statistical difference between shift and day workers. Systolic and diastolic BP levels were correlated with 3% oxygen desaturation index in all subjects after adjustment for potential confounding variables. This association was primarily observed among workers aged >or=40 years, more specifically older shift workers. CONCLUSIONS: A correlation between SDB severity and diastolic BP levels among shift workers aged >or=40 years suggests the importance of screening for SDB among shift workers for BP control.

Adult↗
PubMed2006

The impact of rest breaks on temporal trends in injury risk.

This study examined the impact of rest breaks on temporal trends in industrial accident risks in an attempt to replicate earlier findings of a linear increase in risk as a function of elapsed time on task. In two separate studies, the trend in work-related injuries were studied in relation to the timing of rest breaks. In study one, comparisons were made between on- and off-track workers on weekly rotating three-shift systems operating in a large engineering company. Records of on-duty injuries that occurred over 12 months were examined (N = 4645 incidents). Study two involved interviewing patients who had suffered work-related hand injuries in a variety of occupational settings (N = 407 patients). Hierarchical log linear analysis was used in both studies. In study one, risk increased from the first to the second half-hour of continuous work following a break, but then remained relatively constant in subsequent half-hour periods, although there was a fall in the third half-hour for on-track workers. In some of the data, there was also a decrease in risk in the period leading up to the end of a work period. There was a sharp decline in reported injuries toward the very end of a shift, but otherwise the observed trends did not differ between successive periods of continuous work or between morning, afternoon, and night shifts. In study two, risk increased from the first to the second half-hour of continuous work and then remained relatively constant in the third half-hour. The contrast between the current and previous findings may be due to the relatively unique work environment of the previous study. It is suggested that the current trends reflect the effects of working in a relatively unconstrained task environment, and that causes other than fatigue may underlie the trends observed in both the previous and current studies.

Accident Prevention↗
PubMed2006

Ultradian and asymmetric rhythms of hemispheric processing speed.

Daily changes in cognitive performance have been documented, both in time of day/effect paradigm studies and in time-isolation studies. However, in both types of studies, phenomena such as the "post-lunch dip" have been found that were difficult to explain in terms of theoretical backgrounds. These phenomena may suggest ultradian rhythms in cognitive performance. A number of studies have also shown ultradian and asymmetric rhythms in activity indices of the brain hemispheres. The aim of this study was to test three hypotheses: the first two assumed that there is a significant ultradian frequency in a component of the endogenous rhythm of processing speed, and the third assumed that the ultradian endogenous rhythms of the processing speed (encoding and recognition) of stimuli addressed to the left brain hemisphere differ in period length from those addressed to right hemisphere. During a 24 h constant-routine experiment, the memory performance of 30 participants was measured eight times (every 2.5-3 h), starting at 06:30 h. Parallel sets of words and pictures were shown to subjects in a random order in either the left or the right visual field on a computer screen. The participants pressed one of two buttons in response to the picture or word, or when answering a question concerning the meaning of a presented stimulus. Cosinor analysis was applied to individual time series data. Two significant ultradian components were found in a majority of the time series. Dominant periods were analyzed using three factor ANOVA. The results showed an asymmetry between both hemispheres in the frequency of ultradian rhythms in encoding speed.

Activity Cycles↗
PubMed2006

The use of standardised patients to assess clinical competence: does practice make perfect?

CONTEXT: The use of standardised patients (SPs) is now an integral component of the United States Medical Licensing Examination (USMLE). This new requirement has caused more schools to include SP examinations (SPEs) in their curricula. This study reviews the effect of prior experience with SPs in a medical school curriculum on SPE pass rates. METHODS: This study reviewed the mean scores and pass rates on a 4-station SPE, comparing the performance of 121 US medical school graduates (USMGs) with that of 228 international medical graduates (IMGs). The analysis of USMGs' performance was based upon whether the resident had had previous exposure to an SPE during medical school, while the analysis of IMGs' performance was based upon whether the IMG had taken the Clinical Skills Assessment (CSA) for certification by the Education Commission for Foreign Medical Graduates. A distinction was made between those who had received prior exposure at Mount Sinai School of Medicine's Morchand Center, where the cases utilised were identical to those of the SPE, and those who had gained exposure elsewhere. RESULTS: Neither the mean scores of the IMGs and the USMGs nor the percentage who failed was significantly different relative to prior exposure to SPs. CONCLUSION: Prior exposure to SPs does not appear to have a positive effect on subsequent performance on an SPE unless similar or identical cases are used. However, the type and site of prior exposure limited the influence of the review. In view of the increased use of SPEs in medical schools, the content of prior exposure needs to be more fully established.

Analysis of Variance↗
PubMed2006

Supportive programs increase medical students' research interest and productivity.

BACKGROUND: Advances in biomedical research during the last decade have highlighted the necessity of attracting greater numbers of physicians to careers that include a research component. Physician participation in research is essential to increase the number of clinical and translational studies performed, as well as to educate the public about the importance of clinical trials and to assist in recruiting participants. We hypothesized that attractive research opportunities that included faculty mentoring, recognition of participation, and rewards for accomplishments would encourage medical student participation. METHODS: The Medical Student Research Office was created at Mount Sinai School of Medicine in 1996 to develop structured research programs and advise students looking to undertake a research project. Data from students participating in the summer research program and Medical Student Research Day, from the research section of the Medical Student Performance Evaluation, were collected from 1996 to 2004. RESULTS: For the last 4 years, the majority of medical students did research following the first year of school. Students did basic and clinical research, although most preferred clinically oriented or translational projects. Participation in Research Day and the number of publications suggest that interest is growing, including that by traditionally underrepresented groups. CONCLUSION: Although it is too early to assess the long-term effects, the research programs offered led to greater numbers of students who did research, including those in traditionally underrepresented groups. Moreover, students were highly satisfied with their experiences, with 80% feeling that it increased their interest in applying principles they learned to the practice of medicine.

Biomedical Research↗
PubMed2005

The influence of morningness-eveningness on anxiety and cardiovascular responses to stress.

The relationship between cardiovascular responses to stress and health outcomes is inconsistent. In this study, the effects of morningness-eveningness and time of day upon cardiovascular activity at rest and in response to stress were examined. Sixty morning-types and evening-types completed two testing sessions (one morning, one afternoon) that comprised a battery of three stress tasks and a measure of anxiety. The results failed to support a time of day effect upon cardiovascular activity, but there was evidence of an interaction between time of day and morningness-eveningness upon heart rate (HR) and rate pressure product (RPP; HRxSBP). Evening-types exhibited higher HR and RPP in the afternoon, both at rest and during stress. A time of day effect was shown for mood, with anxiety levels higher in the morning than the afternoon. These results are discussed in terms of their health and methodological implications.

Adolescent↗
PubMed2005

Screening and intervention for alcohol and illicit drug abuse:a survey of internal medicine housestaff.

This study attempts to determine how internal medicine housestaff screen and intervene for problematic alcohol and illicit drug use, as well as identify factors correlating with favorable practices. A cross-sectional survey was administered to 93 medical housestaff. Of 64 (69%) respondents, 94% reported routinely screening new patients for alcohol or illicit drug use, while only 52% routinely quantified alcohol consumption and 28% routinely used a screening instrument. Housestaff were unfamiliar with national guidelines and felt unprepared to diagnose substance use disorders, particularly prescription drug abuse. Most routinely counseled patients with alcohol (89%) or illicit-drug problems (91%), although only a third of these patients were referred for formal treatment. More thorough screening practices were associated with greater treatment optimism, while favorable referral practices were associated with greater optimism about 12-step program benefit and difficulty with management. These findings suggest areas to be addressed in residency curricula on substance abuse.

Adult↗
PubMed2005

Shiftwork locus of control, situational and behavioural effects on sleepiness and fatigue in shiftworkers.

A number of situational and behavioural individual differences moderate the impact of shift and night work. The aims of this study were to identify individual differences correlates of sleep and fatigue-related shiftwork outcomes and examine their potential relative causal impact. Power company shiftworkers completed a questionnaire that measured age/experience, number of dependents, shiftwork locus of control, morningness-eveningness, workload and sleep/health-related behaviours. Shiftwork sleep and fatigue outcome variables were also measured. Hierarchical multiple regression was used to examine predictive contributions of the individual difference variables and to generate path coefficients from situational and psychological predictors through behavioural variables to the outcome variables. Shiftwork-specific internality showed the most systematic significant causal relationships with sleep and fatigue outcomes. While not having as strong a direct causal influence on sleep and fatigue outcomes as internality, the other predictors did show more significant causal effects upon sleep-related behaviours than did internality. Behavioural variables made little contribution to the total causal effects of the predictors on the outcome variables. The results suggest control beliefs to be a moderating factor in shiftwork exposure and the potential utility of this construct in aiding more effective targeting of interventions.

Adult↗
PubMed2005

Modifying effects of perceived adaptation to shift work on health, wellbeing, and alertness on the job among nuclear power plant operators.

This study examined the relationship between perceived adaptation to shift work and shift-related problems. A total of 608 male operators at nuclear power plants completed a set of validated questionnaires including a modified version of the Standard Shiftwork Index, which covered adaptation to shift work, fit to job content, chronotypes, chronic fatigue, sleep, naps, shift work locus of control (SHLOC), psychological health, social/family life, daytime sleepiness, workload, alertness on the job, and lifestyle factors. Participants were divided into two groups according to their perceived level of adaptation to shift work. The good adaptation group showed better outcomes than the poor adaptation group in terms of fit to job content, chronic fatigue, daytime sleep before night shifts, social and family disruption, SHLOC, psychological health, and alertness during night shifts (ps<0.001). Operators who reported good adaptation also took a more frequent, longer nap and more cigarettes during night shifts (ps<0.05). The cross-sectional study design cannot determine a causal relationship between perceived adaptation and shift work problems, yet the present results suggest that the effects of working shifts may be modified by perceptions of shift work adaptation.

Adaptation, Psychological↗
PubMed2002

Stress in medical residency: status quo after a decade of reform?

BACKGROUND: Although curricular reforms have attempted to address sources of stress in medical residency, no recent studies have examined the financial or emotional situations of current medicine residents. OBJECTIVE: To question medicine residents about financial status, educational debt, moonlighting, and psychological issues. DESIGN: Survey distributed in a nonrandomized fashion to medicine residents. SETTING: All 415 U.S. medicine residency programs. RESULTS: According to the questionnaire responses submitted by the 4128 (18%) participating residents, a substantial number of residents had financial and emotional distress that could have interfered with training. The reported educational debt was at least $50 000 for 1657 (42%) of the respondents and at least $100 000 for 737 (19%). The monthly disposable income was $100 or less for 1620 (43%) of the residents, and 637 residents (16%) could not afford safe housing. Among respondents in their 2nd through 5th year of postgraduate training, 2187 (52%) had insufficient funds to purchase books and equipment, and 678 (29%) could not afford the required fees for the American Board of Internal Medicine certifying examination; 2659 (33%) worked as moonlighters, and this percentage increased progressively with increasing educational debt. Four or five depressive symptoms during residency were reported by 1461 (35%) residents. Eight hundred ninety-nine residents (23%) thought they had become less humanistic over the course of their residency training; 2347 (61%) reported becoming more cynical. Female residents were more likely than male residents to report increased cynicism and multiple depressive symptoms. Increased cynicism and depressive symptoms were associated with increasing educational debt. CONCLUSIONS: Despite recent curricular reforms, an alarming number of current medicine residents report depressive symptoms, increasing cynicism, and decreasing humanism, which were associated with increasing educational debt and a need to moonlight for financial survival. Ongoing curricular reform, legislative relief from early loan repayment, and salary increases may be necessary to address these problems.

Employment↗