FACTORS ASSOCIATED WITH THE TIME-BASED PHENOMENOLOGY OF POST-STROKE FATIGUE OVER THE FIRST YEAR AFTER STROKE OCCURRENCE.

Aim - analyze factors associated with certain time-based types of post-stroke fatigue (PSF) over the first year after stroke occurrence. There were examined patients consequently in definite time points after ischemic or hemorrhagic strokes: at hospital stay (234 patients), at 1 month (203), at 3 months (176), at 6 months (156), at 9 months (139) and at 12 months (128). PSF and certain PSF domains were measured by fatigue assessment scale and multidimensional fatigue inventory-20 scale. All PSF cases were divided as early PSF (presented only within the first month after stroke), persistent PSF (presented within the first post-stroke month and later) and late PSF (appeared only at three months observation or later). In univariate logistic regression analysis there were no any significant associations between risk of every time-based PSF types and majority of studied factors. On the other hand, Fazekas scale score was significantly associated with higher risk of persistence of global and mental PSF. Post-stroke functional disability, according to modified Rankin scale, was significantly associated with increased risk of global and physical PSF persistence. Mild cognitive impairments were associated with increased risk of global and mental PSF persistence. The presence of depressive signs at 1 month and 3 months after stroke was significantly associated with increased risk of late PSF (due to increased risk of various PSF components). Management of post-stroke functional abnormalities, mild cognitive impairments and depressive signs probably may be helpful for prevention of early PSF persistence and development of late PSF.

NEUROIMAGING CHARACTERISTICS AND POST-STROKE FATIGUE WITHIN THE FIRST 6 MONTHS AFTER ISCHEMIC STROKES.

Aim - identify neuroimaging characteristics associated with different post-stroke fatigue (PSF) domains within first 6 months after ischemic strokes. There were enrolled in the study 107 patients with acute ischemic strokes. General PSF and certain PSF domains (global, physical, mental, motivational, activity-related) were measured by multidimensional fatigue inventory-20 (MFI-20) scale at hospital stay, in 1, 3 and 6 months after stroke occurrence. Brain MRI studies included cerebral infarct localization, planimetric measurements of infarct volumes, measurement of brain atrophy indexes (bifrontal, bicaudate, cortical atrophy indexes, width of third ventricle) and evaluation of leukoaraiosis severity, according to Fazekas scale. In univariate logistic regression analysis infarcts volumes as well as brain atrophy indexes were not significantly associated with risk of any PSF domain at any time points within first 6 months after ischemic strokes. On the other hand, it had been found reliable associations between subcortical infarcts and increased risk of PSF domains which are related just to physical activity (physical PSF, activity-related PSF) in 1 month after stroke onset and later, as well as reliable associations between infratentorial infarcts and risk of global PSF domain in 3 months after stroke and later. Moreover, it have been revealed significant direct associations between severity of white matter lesions and risk of mental PSF in 3 months after stroke onset and later. Subcortical infarcts may be risk factors for development of physical PSF domain, infratentorial infarcts - risk factors for development of global PSF domain, leukoaraiosis extension - risk factor for development of mental PSF domain but not early than 1 month after stroke occurrence.

FACTORS ASSOCIATED WITH POST-STROKE FATIGUE WITHIN THE FIRST 3 MONTH AFTER STROKE.

Aim - identify socio-demographic, personal and psychological factors associated with certain post-stroke fatigue (PSF) domains within first 3 months after stroke. There were examined patients consequently in definite time points after ischemic or hemorrhagic strokes: at hospital stay (234 patients), in 1 month (203 patients) and in 3 months (176 patients). Global PSF and certain PSF domains were measured by multidimensional fatigue inventory-20 (MFI-20) scale. In multivariate logistic regression analysis the majority of variables (gender, marital status, education level, smoking status, level of alcohol consumption, apathetic impairments, arterial hypertension, atrial fibrillation, ischemic heart disease, diabetes mellitus, body mass index, waist circumference) were not significantly associated with any PSF domain risk at any time point after stroke. On the other hand, it had been found reliable associations between risk of global PSF and employing status before stroke, pre-stroke fatigue, anxiety symptoms, excessive daytime sleepiness, pain. Majority of risk factors for specific PSF domains (physical, mental, activity-related, motivational) are the same as for global PSF. The exception is mild cognitive impairments for mental PSF and depression signs for motivational PSF. Management of modifiable risk factors (anxiety and depression signs, excessive daytime sleepiness, chronic pain) probably may be helpful for PSF prevention within first 3 months after stroke.

FACTORS ASSOCIATED WITH POST-STROKE FATIGUE DURING THE SECOND HALF YEAR AFTER STROKE.

Post-stroke fatigue (PSF) is a common and often debilitating sequel of both ischemic and hemorrhagic strokes Aim - identify socio-demographic, personal and psychological factors associated with different PSF domains over the second half year after stroke occurrence. There were examined patients consequently in definite time points: at 6 months (156 patients), at 9 months (139 patients) and at 12 months (128 patients) after ischemic or hemorrhagic strokes. Global PSF and certain PSF domains (physical, mental, motivational, activity-related) were measured by multidimensional fatigue inventory-20 scale. In univariate logistic regression analysis most of the studied variables (gender, marital status, education level, apathetic impairments, excessive daytime sleepiness, waist circumference, arterial hypertension, ischemic heart disease, atrial fibrillation, diabetes mellitus) were not significantly associated with global PSF as well as with any PSF aspect at 6, 9 and 12 months after stroke occurrence. On the other hand, univariate logistic regression analysis showed reliable associations between risk of global PSF, risk of all PSF domains and anxious as well as depressive signs, reliable associations between risk of mental PSF and cognitive impairments over the second half year after stroke. Multivariate logistic regression analysis revealed that depressive signs and cognitive impairments were independent predictors of mental PSF over studied post-stroke period. Screening and early management of depressive signs, anxious signs and cognitive impairments probably may be helpful for PSF prevention over the second half year after stroke occurrence.

Lightning on Venus inferred from whistler-mode waves in the ionosphere.

The occurrence of lightning in a planetary atmosphere enables chemical processes to take place that would not occur under standard temperatures and pressures. Although much evidence has been reported for lightning on Venus, some searches have been negative and the existence of lightning has remained controversial. A definitive detection would be the confirmation of electromagnetic, whistler-mode waves propagating from the atmosphere to the ionosphere. Here we report observations of Venus' ionosphere that reveal strong, circularly polarized, electromagnetic waves with frequencies near 100 Hz. The waves appear as bursts of radiation lasting 0.25 to 0.5 s, and have the expected properties of whistler-mode signals generated by lightning discharges in Venus' clouds.

Little or no solar wind enters Venus' atmosphere at solar minimum.

Venus has no significant internal magnetic field, which allows the solar wind to interact directly with its atmosphere. A field is induced in this interaction, which partially shields the atmosphere, but we have no knowledge of how effective that shield is at solar minimum. (Our current knowledge of the solar wind interaction with Venus is derived from measurements at solar maximum.) The bow shock is close to the planet, meaning that it is possible that some solar wind could be absorbed by the atmosphere and contribute to the evolution of the atmosphere. Here we report magnetic field measurements from the Venus Express spacecraft in the plasma environment surrounding Venus. The bow shock under low solar activity conditions seems to be in the position that would be expected from a complete deflection by a magnetized ionosphere. Therefore little solar wind enters the Venus ionosphere even at solar minimum.

Ambulatory teaching: do approaches to learning predict the site and preceptor characteristics valued by clerks and residents in the ambulatory setting?

BACKGROUND: In a study to determine the site and preceptor characteristics most valued by clerks and residents in the ambulatory setting we wished to confirm whether these would support effective learning. The deep approach to learning is thought to be more effective for learning than surface approaches. In this study we determined how the approaches to learning of clerks and residents predicted the valued site and preceptor characteristics in the ambulatory setting. METHODS: Postal survey of all medical residents and clerks in training in Ontario determining the site and preceptor characteristics most valued in the ambulatory setting. Participants also completed the Workplace Learning questionnaire that includes 3 approaches to learning scales and 3 workplace climate scales. Multiple regression analysis was used to predict the preferred site and preceptor characteristics as the dependent variables by the average scores of the approaches to learning and perception of workplace climate scales as the independent variables. RESULTS: There were 1642 respondents, yielding a 47.3% response rate. Factor analysis revealed 7 preceptor characteristics and 6 site characteristics valued in the ambulatory setting. The Deep approach to learning scale predicted all of the learners' preferred preceptor characteristics (beta = 0.076 to beta = 0.234, p < .001). Valuing preceptor Direction was more strongly associated with the Surface Rational approach (beta = .252, p < .001) and with the Surface Disorganized approach to learning (beta = .154, p < 001) than with the Deep approach. The Deep approach to learning scale predicted valued site characteristics of Office Management, Patient Logistics, Objectives and Preceptor Interaction (p < .001). The Surface Rational approach to learning predicted valuing Learning Resources and Clinic Set-up (beta = .09, p = .001; beta = .197, p < .001). The Surface Disorganized approach to learning weakly negatively predicted Patient Logistics (beta = -.082, p = .003) and positively the Learning Resources (beta = .088, p = .003). Climate factors were not strongly predictive for any studied characteristics. Role Modeling and Patient Logistics were predicted by Supportive Receptive climate (beta = .135, p < .001, beta = .118, p < .001). CONCLUSION: Most site and preceptor characteristics valued by clerks and residents were predicted by their Deep approach to learning scores. Some characteristics reflecting the need for good organization and clear direction are predicted by learners' scores on less effective approaches to learning.

Assessing the relationship of learning approaches to workplace climate in clerkship and residency.

PURPOSE: To determine what approaches to learning are adopted by clinical clerks and residents and whether these approaches are associated with demographic factors, specialty, level of training, and perceptions of the workplace climate. METHOD: In 2001-02, medical clerks (n = 532) and residents (n = 2,939) at five medical schools in Ontario, Canada, were mailed the Workplace Learning Questionnaire. The correlation between the approaches to learning at work and perceived workplace climate and the influence of gender, age, location, residency program and level of training on outcomes were measured. RESULTS: A total of 1,642 clerks and residents responded (47%). The factor structure and reliability of the Workplace Learning Questionnaire were confirmed for these respondents. A surface-disorganized approach to learning was correlated with perception of heavy workload (r = .401, p < .001). The deep approach to learning was correlated with perception of choice-independence in the workplace and a supportive-receptive workplace (r = .32, p < .001; r = .23, p < .001). The climate factors, perception of choice-independence and supportive-receptive workplace, were correlated (r = .60, p < .001). There were significant differences among the mean scores for scales based on residency, year of training, and location of training. CONCLUSIONS: Perception of the workplace climate was associated with the approach to learning in the workplace of clerks and residents. Perception of heavy workload was associated with less effective approaches to learning. These associations varied with the residency program and the level of training.

Does PBL Matter? Relations Between Instructional Context, Learning Strategies, and Learning Outcomes.

Purpose: To compare learning strategies used in Problem based learning (PBL) and lectures, and the relations between learning strategies and learning outcomes to determine how different learning strategies associated with PBL and lectures contribute to aspects of clinical competence. Design: The 52-item learning strategies questionnaire was given to preclinical medical students during lecture and PBL sessions in first and third year from 1994 to 1998. Response patterns were compared across the two contexts and factor structures investigated. Regression analyses examined relations between learning strategies and outcomes. Main Outcome Measures/Results: Comparison of responses on the 326 complete pairs of lecture and PBL questionnaires indicated differences at the 0.05 level on 44 of the 52 items. The mean differences were greater than 0.5 (on a 5 point scale) at the 0.001 level for 20 items. Of these, five strategies were used more often in PBL and 15 in lectures. Comparisons of learning strategy use across years showed significant changes with time in both instructional contexts. Principal component analysis revealed a stable factor structure with 4 factors distinctly associated with PBL and 4 factors with the lecture learning context. The remaining 6 factors were mixed and independent of context. Exploratory regression analysis revealed that learning outcomes in examinations were influenced by learning strategies. Multiple choice performance was positively predicted by learning associated with lecture class notes and negatively by group work, whereas the OSCE (objective structured clinical exam) performance was positively predicted by class participation in PBL, self-directed note making and lecture class notes. Conclusion: We have developed a learning strategies questionnaire that shows that students' learning strategies are influenced by instructional context, and patterns of learning strategy use change over time. There is tentative evidence that the students' learning strategies influence learning outcomes.

Development of the approaches to work and workplace climate questionnaires for physicians.

Two questionnaires were developed to investigate the workplace learning of physicians. The Approaches to Work Questionnaire for Physicians and the Workplace Climate Questionnaire for Physicians were adapted from general measures developed by Kirby, Knapper, Evans, Carty, and Gadula. These questionnaires were administered to a random sample of Ontario physicians. Consistent with the results of Kirby et al., three dimensions of approaches to work were observed: Deep. Surface-Rational, and Surface-Disorganized. Three dimensions of workplace climate were also found, Supportive-Receptive, Choice-Independence, and Workload. Results indicate that physicians adopt primarily a Deep approach to work, but that there is a smaller tendency toward Surface-Disorganized learning, one that is strongly correlated with perceptions of heavy workload. The Deep approach was associated with work environments perceived to be Supportive-Receptive and offer Choice-Independence. The use of these questionnaires in research and practice is discussed.

Herpes genitalis in a student population.

Increased reporting of genital herpes has led to claims in the lay press of an epidemic of herpes genitalis. In a study at Queen's University Student Health Service during a nine-month period, a first diagnosis of genital herpes was made in 5.9/1,000 students attending the clinic. Excluding those patients with recurrent illness by history, the incidence of genital herpes was 4.5/1,000. Recovery of the virus was successful in 91 percent of attempted cultures. Complications were low. Genital herpes is an important sexually transmitted disease in the student population, but claims of an epidemic are exaggerated.

General practice training in the Oxford region. Ideas for community teaching practices.

Vocational training for general practice in Great Britain developed in local medical communities, often separate from undergraduate teaching associated with universities. Courses for skill development in teaching, support in the form of local trainers' groups, and peer assessment through practice assessment visits have contributed to the success of this model. The experience in the Oxford region can contribute to successful development of community teaching in Canada.

Vitamin B12 replacement. To B12 or not to B12?

OBJECTIVE: To review the evidence for an expanded approach to identifying and treating patients with cobalamin deficiency. Controversy surrounds this issue. Some authors claim that seven times more patients are treated than have true deficiency. New diagnostic tests and identification of patients who have neurologic consequences without hematologic abnormalities suggest that some of these patients have a vitamin B12 tissue deficiency. QUALITY OF EVIDENCE: A MEDLINE search of English-language literature from 1990 to 1995 revealed retrospective and prospective studies of diagnostic tests; prospective surveys; a cohort study; and retrospective and prospective case series, some with control groups. No double-blind controlled trials of treatment were found. MAIN FINDINGS: Some patients with neuropsychiatric abnormalities develop a cobalamin tissue deficiency that can be detected by elevated serum homocysteine and methylmalonic acid levels despite normal serum vitamin B12 levels without macrocytic anemia. Serum cobalamin testing is neither sensitive nor specific in the low normal range for cobalamin deficiency. Treatment recommendations vary because no controlled trials support any recommendations. Oral cobalamin is an underused alternative to parenteral treatment. CONCLUSION: Until the newer diagnostic tests become widely available, family physicians must continue to take a traditional approach to diagnosing vitamin B12 deficiency. There is, however, support for a clinical trial of treatment in patients with neuropsychiatric symptoms.

Hormone replacement therapy. Risks, benefits, and costs.

Epidemiologic evidence on the risks and benefits of hormone replacement therapy (HRT) for postmenopausal women is accumulating. The apparent 50% reduction in risk of cardiovascular mortality could lead to universal HRT. Until a prospective, controlled trial is concluded, women must consider all the consequences of HRT. For the undecided, who would take HRT only to prevent osteoporosis, bone mass estimates might be warranted.

Indications for Vitamin B(12) Therapy: A retrospective study.

A retrospective chart audit was undertaken to determine the clinical reasons for vitamin B(12) therapy in family practice. Abnormal laboratory tests and symptoms were the most common reasons for initiating therapy. The high proportion of cases with little supporting evidence of B(12) deficiency suggests that other factors influence treatment decisions.

Postal survey of approaches to learning among Ontario physicians: implications for continuing medical education.

OBJECTIVES: To understand the approaches to learning of practising physicians in their workplace and to assess the relation of these approaches to their motivation for, preferred methods of, and perceived barriers to continuing medical education. DESIGN: Postal survey of 800 Ontario physicians. PARTICIPANTS: 373 physicians who responded. MAIN OUTCOME MEASURES: Correlations of approaches to learning and perceptions of workplace climate with methods, motives, and barriers to continuing medical education. RESULTS: Perceived heavy workload was significantly associated with the surface disorganised (r=0.463, P<0.01) and surface rational approach (r=0.135, P<0.05) to learning. The deep approach to learning was significantly correlated with a perception of choice-independence and a supportive-receptive climate at work (r=0.341 and 0.237, P<0.01). Physicians who adopt a deep approach to learning seem to be internally motivated to learn, whereas external motivation is associated with surface approaches to learning. Heavy workload and a surface disorganised approach to learning were correlated with every listed barrier to continuing medical education. The deep approach to learning was associated with independent learning activities and no barriers. CONCLUSIONS: Perception of the workplace climate affects physicians' approaches to learning at work and their motivation for and perceived barriers to continuing medical education. Younger, rural, family physicians may be most vulnerable to feeling overworked and adopting less effective approaches to learning. Further work is required to determine if changing the workplace environment will help physicians learn more effectively.

Randomised equivalence trial comparing three month and six month follow up of patients with hypertension by family practitioners.

OBJECTIVE: To compare blood pressure control, satisfaction, and adherence to drug treatment in patients with treated hypertension followed up by their family physicians either every three months or every six months for three years. DESIGN: Randomised equivalence clinical trial. Settings 50 family practices in south eastern Ontario, Canada. PARTICIPANTS: 609 patients aged 30-74 years with essential hypertension receiving drug treatment whose hypertension had been controlled for at least three months before entry into the study. RESULTS: 302 patients were randomly assigned to follow up every three months and 307 to follow up every six months. Baseline variables in the two groups were similar. As expected, patients in the six month group had significantly fewer visits, but patients in both groups visited their doctor more frequently than their assigned interval. Mean blood pressure was similar in the groups, as was control of hypertension. Patient satisfaction and adherence to treatment were similar in the groups. About 20% of patients in each group had blood pressures that were out of control during the study. CONCLUSIONS: Follow up of patients with treated essential hypertension every six months is equivalent to follow up every three months. Patient satisfaction and adherence to treatment are the same for these follow up intervals. As about 20% of patients' hypertension was out of control at any time during the study in both groups, the frequency of follow up may not the most important factor in the control of patients' hypertension by family practitioners.