Evidence-based medicine in primary care: qualitative study of family physicians

Background

The objectives of this study were: a) to examine physician attitudes to and experience of the practice of evidence-based medicine (EBM) in primary care; b) to investigate the influence of patient preferences on clinical decision-making; and c) to explore the role of intuition in family practice.

Method

Qualitative analysis of semi-structured interviews of 15 family physicians purposively selected from respondents to a national survey on EBM mailed to a random sample of Canadian family physicians.

Results

Participants mainly welcomed the promotion of EBM in the primary care setting. A significant number of barriers and limitations to the implementation of EBM were identified. EBM is perceived by some physicians as a devaluation of the 'art of medicine' and a threat to their professional/clinical autonomy. Issues regarding the trustworthiness and credibility of evidence were of great concern, especially with respect to the influence of the pharmaceutical industry. Attempts to become more evidence-based often result in the experience of conflicts. Patient factors exert a powerful influence on clinical decision-making and can serve as trumps to research evidence. A widespread belief that intuition plays a vital role in primary care reinforced views that research evidence must be considered alongside other factors such as patient preferences and the clinical judgement and experience of the physician.

Discussion

Primary care physicians are increasingly keen to consider research evidence in clinical decision-making, but there are significant concerns about the current model of EBM. Our findings support the proposed revisions to EBM wherein greater emphasis is placed on clinical expertise and patient preferences, both of which remain powerful influences on physician behaviour.

     

Constitutive EGFR signaling confers a motile phenotype to neural stem cells

The epidermal growth factor receptor (EGFR) has been shown to play an important role in brain development, including stem and precursor cell survival, proliferation, differentiation, and migration. To further examine the temporal and spatial requirements of erbB signals in uncommitted neural stem cells (NSCs), we expressed the ligand-independent EGF receptor, EGFRvIII, in C17.2 NSCs. These NSCs are known to migrate and to evince a tropic response to neurodegenerative environments in vivo but for which an underlying mechanism remains unclear. We show that enhanced erbB signaling via constitutive kinase activity of EGFRvIII in NSCs sustains an immature phenotype and enhances NSC migration.     

Height,weight, weight change,and ovarian cancer risk in the Netherlands cohort study on diet and cancer

Although many studies have been conducted to investigate the relation between anthropometry and the risk of ovarian cancer, their results have been inconsistent. The Netherlands Cohort Study on Diet and Cancer was initiated in 1986. A self-administered questionnaire on dietary habits and other risk factors for cancer was completed by 62,573 women. Follow-up for cancer was implemented by annual record linkages with the Netherlands Cancer Registry. After 7.3 years of follow-up, 172 incident cases of invasive epithelial ovarian cancer were available for analysis. Multivariate analysis yielded a rate ratio of ovarian cancer for women with adult height of more than 175 cm, compared with those with height of less than or equal to 160 cm, of 2.17 (95% confidence interval: 1.14, 4.13; p trend = 0.01). The rate ratio for women with a body mass index of more than 30 kg/m(2) was 1.69 (95% confidence interval: 1.00, 2.86), compared with women with a Quetelet index of less than 25 kg/m(2), with p trend = 0.06. Rate ratios for weight and body mass index at age 20 years were nonsignificantly increased in the intermediate categories. These data support a positive association between height (and to a lesser extent body mass) and ovarian cancer risk in this population of postmenopausal women.     

Changes in frequency of premature complexes and heart rate variability related to shift work

OBJECTIVES—To investigate whether an increased risk of cardiovascular disease might be caused by increased arrhythmogeneity and by unfavourable changes in autonomic cardiac control the changes in the occurrence of premature complexes (PVCs) and in heart rate variability (HRV) were studied in subjects who started to work in shifts.
METHODS—1 Year changes in frequency of PVCs and HRV were measured in 49 shift workers and 22 control subjects working in daytime. All respondents were starting in a new job in integrated circuit or waste incinerator plants.
RESULTS—The incidence of PVC increased significantly in shift workers over the 1 year follow up, compared with daytime workers. The frequency of ventricular extrasystoles increased in 48.9% of the shift workers, and in 27.3% of the daytime workers. The Spearman correlation coefficient between the number of nights worked and the change in PVCs was 0.33 (p=0.004). A small non-significant unfavourable change in HRV was found in both the shift and daytime workers.
CONCLUSIONS—A change in arrhythmogeneity, but not in cardiac autonomic control, might explain the increased risk of cardiovascular disease in shift workers.


Keywords: arrhythmia; heart rate; shift work     

Gastrointestinal surgery and gastroenterology. XIII. Classification and diagnosis of perianal fistulas

Intersphincteric abscesses due to inflammation of an anal gland are the origin of most perianal fistulas. Perianal fistulas are classified into four types. Intersphincteric and transsphincteric fistulas are the most common. The appropriate surgical treatment of perianal fistulas is dependent upon their correct classification. Despite new imaging-techniques, physical examination of the perianal region remains of paramount importance for the preoperative classification of perianal fistulas. At present, endoanal ultrasound with the injection of hydrogen peroxide into the fistulous tract, is advocated as the most suitable method for the preoperative imaging of perianal fistulas.     

The human cell line PER.C6 provides a new manufacturing system for the production of influenza vaccines

Influenza viruses for vaccine production are currently grown on embryonated eggs. This manufacturing system conveys many major drawbacks such as inflexibility, cumbersome down stream processing, inability of some strains to replicate on eggs to high enough yields, and selection of receptor-binding variants with reduced antigenicity. These limitations emphasize the need for a cell line-based production system that could replace eggs in the production of influenza virus vaccines in a pandemic proof fashion. Here we present the efficient propagation of influenza A and B viruses on the fully characterized and standardized human cell line PER.C6.     

Asthma attacks with eosinophilia predict mortality from chronic obstructive pulmonary disease in a general population sample

We studied the association between allergy defined as eosinophilia (>/= 275 cells/mm(3)) and/or positive skin tests (sum score >/= 3) and mortality from chronic obstructive pulmonary disease (COPD) after adjustment for major risk factors. In addition, we investigated this association in subgroups of respiratory symptoms and lung function. We used data from 7,556 participants of the respiratory surveys in 1964 -1972 in the general populations of Vlagtwedde, Vlaardingen, and Meppel (The Netherlands; mean age +/- SD: 39.3 yr +/- 14 in the 1960s). In 1995, the vital status was available (5,135 alive, 106 lost to follow-up, 121 primary deaths from COPD, and 2,194 other primary causes of which 137 had a secondary death cause from COPD. Positive skin tests were not associated with increased COPD mortality. The association between eosinophilia and COPD mortality was restricted to those who had reported asthma attacks and was present for both COPD as a primary cause (relative risk [RR] = 4.80; 95% confidence interval [CI] 1.9 to 11.9) and combined primary and secondary causes of death (RR = 3. 90; 95% CI 2.05 to 7.40). We conclude that eosinophilia with asthma attacks is a risk factor for COPD mortality in addition to known risk factors also found in our study such as male gender, older age, current smoking, low lung function, underweight, and dyspnea.