Current Knowledge on Factor V Leiden Mutation as a Risk Factor for Recurrent Venous Thromboembolism: A Systematic Review and Meta-Analysis

Background

Thrombophilia screening is widely done in clinical practice, and it is claimed that the extent of venous thromboembolism (VTE) recurrence risk in patients with common defects is still not fully understood.

Aim

We aimed to summarize data of all observational studies prospectively assessing the association of heterozygous factor V Leiden (FVL) mutation and recurrent VTE in patients with VTE, and to calculate pooled relative risks (RR), overall and in various subgroups.

Methods

We searched MEDLINE and EMBASE databases for cohort studies prospectively assessing VTE recurrence in patients with and without FVL mutation (PROSPERO: CRD42021182800). Data were extracted on cohort and study-level. The methodological quality was assessed using the Newcastle-Ottawa Scale (NOS). RR were calculated overall and in subgroups using a random-effects model.

Results

From 31 cohorts, 24 studies were finally included summarizing 13,571 patients. Heterozygous FVL mutation was identified in 2,840 individuals (21%). The methodological quality was estimated to be high in 20 studies (83%). The overall RR was 1.46 (95% CI: 1.31, 1.64), consistent across subgroups.

Conclusions

Pooling all high-quality epidemiological data, the risk of recurrent VTE was increased by 46% in patients with heterozygous FVL mutation. Against the background of established risk factors, the FVL mutation plays only a marginal role in the risk assessment for recurrent VTE.

Resource Discovery: Identifying, Evaluating and Integrating Digital Networked Resources Within the Learning Process

The phenomenal popularity of the World Wide Web (WWW) is now well documented, and there is a broad acceptance of the range of digital networked educational materials in the field of medicine available through this medium. Such is the popularity of the WWW, that students will increasingly expect an element of course delivery to be supported through it: they will be aware that lecture notes, case studies, MCQs and entire courses even, are available worldwide. The pervasive nature of the medium is convincingly illustrated by the example of UCLA this summer, where the provision of a web page for every undergraduate course in its largest unit, the College of Letters and Science, became mandatory (Young 1997).

According to the Dearing Report (point 13.3), 'for the majority of students, over the next ten years the delivery of some course materials and much of the organisation and communication of course arrangements will be conducted by computer' (NCEHE, 1997). While the WWW offers an excellent medium for course administration, this paper focuses primarily on issues relating to the use of the WWW for course content delivery: examples of evaluation initiatives that have been undertaken to date are reviewed, and models of integrating networked resources in the context of course delivery are considered.

A BEME systematic review of UK undergraduate medical education in the general practice setting: BEME Guide No. 32

BACKGROUND

General practice is increasingly used as a learning environment in undergraduate medical education in the UK.

AIM

The aim of this project was to identify, summarise and synthesise research about undergraduate medical education in general practice in the UK.

METHODS

We systematically identified studies of undergraduate medical education within a general practice setting in the UK from 1990 onwards. All papers were summarised in a descriptive report and categorised into two in-depth syntheses: a quantitative and a qualitative in-depth review.

RESULTS

169 papers were identified, representing research from 26 UK medical schools. The in-depth review of quantitative papers (n = 7) showed that medical students learned clinical skills as well or better in general practice settings. Students receive more teaching, and clerk and examine more patients in the general practice setting than in hospital. Patient satisfaction and enablement are similar whether a student is present or not in a consultation, however, patients experience lower relational empathy. Two main thematic groups emerged from the qualitative in-depth review (n = 10): the interpersonal interactions within the teaching consultation and the socio-cultural spaces of learning which shape these interactions. The GP has a role as a broker of the interactions between patients and students. General practice is a socio-cultural and developmental learning space for students, who need to negotiate the competing cultures between hospital and general practice. Lastly, patients are transient members of the learning community, and their role requires careful facilitation.

CONCLUSIONS

General practice is as good, if not better, than hospital delivery of teaching of clinical skills. Our meta-ethnography has produced rich understandings of the complex relationships shaping possibilities for student and patient active participation in learning.

Dieting to reduce body weight for controlling hypertension in adults

OBJECTIVES

Evaluate whether weight-loss diets are more effective than regular diets or other antihypertensive therapies in controlling blood pressure and preventing morbidity and mortality in hypertensive adults.

SEARCH STRATEGY

MEDLINE and The Cochrane Library were searched through November 1997. Trials known to experts in the field were included through June 1998.

SELECTION CRITERIA

For inclusion in the review, trials were required to meet each of the following criteria: 1) randomized controlled trials with one group assigned to a weight-loss diet and the other group assigned to either normal diet or antihypertensive therapy; 2) ambulatory adults with a mean blood pressure of at least 140 mm Hg systolic and/or 90 mm Hg diastolic; 3) active intervention consisting of a calorie-restricted diet intended to produce weight loss (excluded studies simultaneously implementing multiple lifestyle interventions where the effects of weight loss could not be disaggregated); and 4) outcome measures included weight loss and blood pressure.

DATA COLLECTION AND ANALYSIS

Studies were dual abstracted by two independent reviewers using a standardized form designed specifically for this review. The primary mode of analysis was qualitative; graphs of effect sizes for individual studies were also used.

MAIN RESULTS

Eighteen trials were found. Only one small study of inadequate power reported morbidity and mortality outcomes. None addressed quality of life or general well being issues. In general, participants assigned to weight-reduction groups lost weight compared to control groups. Six trials involving 361 participants assessed a weight-reducing diet versus a normal diet. The data suggested weight loss in the range of 4% to 8% of body weight was associated with a decrease in blood pressure in the range of 3 mm Hg systolic and diastolic. Three trials involving 363 participants assessed a weight-reducing diet versus treatment with antihypertensive medications. These suggested that a stepped-care approach with antihypertensive medications produced greater decreases in blood pressure (in the range of 6/5 mm Hg systolic/diastolic) than did a weight-loss diet. Trials that allowed adjustment of participants' antihypertensive regimens suggested that patients required less intensive antihypertensive drug therapy if they followed a weight-reducing diet. Data was insufficient to determine the relative efficacy of weight-reduction versus changes in sodium or potassium intake or exercise.

REVIEWER'S CONCLUSIONS

Weight-reducing diets in overweight hypertensive persons can affect modest weight loss in the range of 3-9% of body weight and are probably associated with modest blood pressure decreases of roughly 3 mm Hg systolic and diastolic. Weight-reducing diets may decrease dosage requirements of persons taking antihypertensive medications.