Mayer Brezis

Misrepresentation of health risks by mass media

Abstract Background Mass media are a leading source of health information for general public. We wished to examine the relationship between the intensity of media coverage for selected health topics and their actual risk to public health. Methods Mass media reports in the United States on emerging and chronic health hazards (severe acute respiratory syndrome (SARS), bioterrorism, West Nile Fever, AIDS, smoking and physical inactivity) were counted for the year 2003, using LexisNexis database. The number of media reports for each health risk was correlated with the corresponding death rate as reported by the Centers for Disease Control and Prevention. Results The number of media reports inversely correlated with the actual number of deaths for the health risks evaluated. SARS and bioterrorism killed less than a dozen people in 2003, but together generated over 100 000 media reports, far more than those covering smoking and physical inactivity, which killed nearly a million Americans. Conclusions Emerging health hazards are over-reported in mass media by comparison to common threats to public health. Since premature mortality in industrialized societies is most often due to well-known risks such as smoking and physical inactivity, their under-representation on public agendas may cause suboptimal prioritization of public health resources.

Quality of informed consent for invasive procedures

OBJECTIVE To assess quality of informed consent among patients undergoing procedures and patients preferences about decision-making. DESIGN Cross-sectional survey of hospitalized patients about informed consent before surgery or other procedures. Preference for decision-making was elicited in hospitalized and ambulatory patients. SETTING Large academic general hospital and 10 general clinics, over the years 2002-04. INTERVENTION Data of initial survey were presented at staff meetings, recommending asking patients to restate what was explained to them. MAIN OUTCOME MEASURES Rate of patients recall for explanations on risks and alternative options; rate of patients preferring shared, autonomous and paternalistic modes of decision-making; degree of satisfaction from the decision-making. RESULTS Half of the patients did not recall receiving explanations about risks and two-third did not remember discussion of alternative options. The intervention failed, <10% of patients being asked to re-state what was explained to them. Expectations about decision varied: approximately 60% favored shared decision, nearly 20% preferred autonomous decision and the remainder wanted physicians to make decisions. Satisfaction was rated as good or very good by 80% of patients. CONCLUSIONS Most patients do not remember receiving explanations about risks or alternatives for procedures, and physicians resist attempts to improve informed consent. Tools should be developed to measure the quality of consent. Since patients significantly differ in their preferred mode of decision-making, the informed consent should be patient-specific.

The impact of an evidence-based medicine educational intervention on primary care physicians: a qualitative study.

BackgroundAttitudes and barriers to implementing EBM have been examined extensively, but scant evidence exists regarding the impact of EBM teaching on primary care physicians’ point of care behavior.ObjectiveGaining insight into behavioral and attitudinal changes of facilitators and participants during a multifaceted EBM educational intervention.Design, setting, and participantsA qualitative study on primary care physicians and facilitators from a large HMO selected from the intervention arm of a parallel controlled trial using purposeful sampling. We conducted focus groups with 13 facilitators and 17 physicians and semi-structured interviews with 10 facilitators and 11 physicians.ResultsBoth facilitators and participants believed EBM enhanced the quality of their practice. The intervention affected attitudes and knowledge, but had little impact on physicians’ ability to utilize pre-appraised resources at the point of care. Using EBM resources during consultation was perceived to be a complex task and impractical in a busy setting. Conversely, a positive impact on using medication databases was noted. Medication databases were perceived as easy to use during consultations in which the benefits outweighed the barriers. The intervention prompted physicians to write down clinical questions more frequently and to search for answers at home.ConclusionsThis study underlines the need not only to enhance EBM skills, but also to improve the ease of use of EBM resources at the point of care. Tasks should be simplified by tailoring evidence-based information retrieval systems to the busy clinical schedule. Participants’ recommendations to establish an HMO decision support service should be considered.

Endotoxin-Induced Renal Failure

The pathogenesis of sepsis-induced renal failure is multifactorial and only partially understood. In these studies we evaluated intrarenal microcirculatory changes during endotoxemia and the potential role of nitric oxide (NO) and endothelin in these changes. In anesthetized rats endotoxin infusion [lipopolysaccharide (LPS), Escherichia coli serotype 0127:B8; 10 mg/kg/h] resulted in hypotension and a transient enhancement of renal blood flow, with cortical vasodilation and a loss of outer medullary vasodilatory response to hypotension. The initial cortical vasodilation was abolished by the NO synthase inhibitor NG-nitro-L-arginine methyl ester, but not by indomethacin. Direct NO measurements disclosed a gradual rise in cortical NO, despite the waning vasodilatory effect, suggesting antagonizing vasoconstrictive stimuli. In rats pretreated by LPS (1 mg/kg i.p. 1 day earlier) the renal blood flow was reduced to 55% of that of controls. Moreover, the vasodilatory response to LPS infusion was converted into profound cortical and medullary vasoconstriction. In these preconditioned rats the endothelin receptor antagonist bosentan evoked a vasodilatory response and attenuated the vasoconstrictive reaction to LPS infusion. The infusion of another LPS (E. coli serotype 0111:B4) exerted predominant and protracted renal vasodilation without hypotension. In conclusion, different LPS exert diverse systemic and renal hemodynamic responses. The 0127:B8 serotype attenuates renal medullary vasodilation during hypotension, exerts transient cortical vasodilation, and following repeated exposure induces profound renal vasoconstriction. NO and endothelin participate in LPS-induced vascular responses that may predispose to hypoxic tubular damage.

Effects of Moderate Intensity Glycemic Control After Cardiac Surgery

BACKGROUND The impact of intensive insulin therapy on the clinical outcomes of hospitalized patients is highly controversial. We used a protocol based on dynamic insulin administration targeted to achieve moderately tight glycemic control and tested its impact on clinical outcomes after cardiac surgery. METHODS Patients with diabetes mellitus or random blood glucose greater than 150 mg/dL were treated in the intensive care unit with intravenous insulin, followed by a multi-injection protocol consisting of 4 glargine/aspart insulin injections in the ward, with a glycemic target of 110 to 150 mg/dL. The study cohort (n = 410) consisted of consecutive patients undergoing cardiothoracic surgery. Control patients (n = 207) were admitted during the first 8 months and treated according to standard of care. The intervention group of patients (n = 203) were operated on during the following 8 months. The main outcome measures were glycemic control and the rate of postsurgery infections. RESULTS During the intervention, mean blood glucose ± SD was 151 ± 19 mg/dL and 157 ± 32 mg/dL in the intensive care unit and ward, respectively, versus 166 ± 27 mg/dL and 184 ± 46 mg/dL during the control period (p < 0.0001). The incidence of hypoglycemia (blood glucose less than 60 mg/dL) was low and similar in the two groups (2.5% control versus 3% intervention). Intensive insulin treatment decreased the risk for infection from 11% to 5% (56% risk reduction, p = 0.018), mainly by reducing the incidence of graft harvest site infection (6.9% versus 2.5%, p = 0.034). The incidence of atrial fibrillation after coronary artery bypass graft surgery decreased from 30% to 18% (39% risk reduction; p = 0.042). CONCLUSIONS Moderate-intensity dynamic blood glucose control after cardiac surgery is effective and safe, and is associated with improved clinical outcomes.

A systematic review of interventions to increase awareness, knowledge, and folic acid consumption before and during pregnancy.

Objective. We conducted a systematic review of studies designed to increase awareness of, knowledge about, and consumption of folic acid before and during pregnancy. Data sources. Studies were identified from Cochrane Library, Medline, and the references of primary studies and reviews. Study inclusion and exclusion criteria. Studies included randomized controlled trials, quasi-experimental interrupted time series studies, follow-up studies, case-control studies, and before-and-after studies, all of which were conducted between 1992 and 2005 on women ages 15 to 49 years and/or health professionals, evaluating awareness and/or knowledge and/or consumption of folic acid both before and after intervention. Studies were excluded if data were not presented both before and after intervention or were other outcomes than those mentioned here. Data extraction. Data were extracted in relation to characteristics of studies, participants, interventions, and outcomes. Data synthesis. Because of heterogeneity, we performed a narrative synthesis describing the direction and the size of effects. Results. On average, womens awareness increased from 60% to 72%, knowledge from 21% to 45%, and consumption from 14% to 23%. Conclusions. Interventions had a positive effect on folic acid intakes before and during pregnancy, although the average usage reached less than 25%. So what? Further research is needed to design more effective interventions to increase periconceptional use of folic acid.

Tissue oxygenation modifies nitric oxide bioavailability.

Objective: Because changes in blood oxygenation acutely alter vascular tone, we explored a possible modulation of nitric oxide‐induced vasodilation (nitrovasodilation) by oxygen.

Insoles for prevention and treatment of back pain: a systematic review within the framework of the Cochrane Collaboration Back Review Group.

Study Design. A systematic review of randomized controlled trials. Objective. To determine the effectiveness of shoe insoles in the prevention and treatment of nonspecific back pain compared with placebo, no intervention, or other interventions. Summary of Background Data. There is lack of theoretical and clinical knowledge of the use of insoles for prevention or treatment of back pain. Methods. We searched electronic databases from inception to October 2008. We reviewed reference lists in review articles, guidelines, and in the included trials; conducted citation tracking; and contacted individuals with expertise in this domain. One review author conducted the searches and blinded the retrieved references for authors, institution, and journal. Two review authors independently selected the relevant articles. Two different review authors independently assessed the methodological quality and clinical relevance and extracted the data from each trial using the criteria recommended by the Cochrane Back Review Group. Results. Six randomized controlled trials met inclusion criteria: 3 examined prevention of back pain (2061 participants) and 3 examined mixed populations (256 participants) without being clear whether they were aimed at primary or secondary prevention or treatment. No treatment trials were found. There is strong evidence that the use of insoles does not prevent back pain. There is limited evidence that insoles alleviate back pain or adversely shift the pain to the lower extremities. Conclusion. There is strong evidence that insoles are not effective for the prevention of back pain. The currentevidence on insoles as treatment for low back pain does not allow any conclusions.

Effect of Radiocontrast Agents on Intrarenal Nitric Oxide (NO) and NO Synthase Activity

Background/Aims: Contrast media (CM) induce a biphasic renal hemodynamic response, with late prominent cortical vasoconstriction and marked outer medullary vasodilation. The objective of the study was to explore a possible role for altered nitric oxide (NO) production or bioavailability in these hemodynamic responses. Methods: We explored the impact of CM (sodium iothalamate) upon rat renal NO synthase (NOS) activity (citrulline recovery) and NO (using a NO electrode). Results: The cortical NOS activity following CM was 11.5 ± 1.0 versus 13.8 ± 1.1 nmol/gww/min (gww = gram wet weight) in controls (p = 0.16, NS). In rats pretreated with the nonselective endothelin antagonist bosentan, CM reduced the cortical NOS activity to 8.5 ± 1.2 nmol/gww/min (p < 0.005 vs. controls). Cortial NO readings declined over 30 min following CM by 13 ± 8% (p < 0.05, Anova), in parallel with the decline in cortical blood flow. The outer medullary NOS activity was not affected by CM (5.2 ± 1.5 vs. 5.5 ± 1.3) nmol/gww/min in controls) or bosentan. Nevertheless, the outer medullary NO reading increased by 36 ± 23% (p < 0.05), with a concomitant increase in regional blood flow. Conclusion: In the cortex, CM might reduce the NOS activity (an effect blunted by endothelin release). This may potentiate the effect of endothelin to induce regional vasoconstriction. In the outer medulla, the vasodilatory response to CM does not seem to be mediated by enhanced NOS activity and might reflect increased local NO bioavailability as the result of regional hypoxia.

Evidence based case report. Antibiotic treatment for spontaneous bacterial peritonitis.

A 55 year old woman, previously diagnosed with cirrhosis secondary to chronic hepatitis C infection, was admitted to our department with fever. She seemed well and had no focal symptoms or signs of infection. As ascites was present, she had paracentesis. This yielded a Gram negative clear fluid with a polymorphonuclear count of 700 cells/mm3. We thought that secondary peritonitis was unlikely and diagnosed spontaneous bacterial peritonitis. She had had no previous episodes or prophylactic antibiotic treatment. Empirical treatment with cefotaxime (2 g every 8 hours) was started. When admitting the patient, the junior doctor had access to two main databases: the Cochrane Library, which contained no relevant information,1 and UpToDate, which recommended intravenous cefotaxime or oral ofloxacin for patients with uncomplicated spontaneous bacterial peritonitis.2 On the morning after her admission, there was a lively discussion at the departmental meeting. The main question was whether the patient could have started taking oral ofloxacin, given her excellent clinical condition. Other questions were raised about the strength of the evidence supporting the standard treatment with cefotaxime and the ideal dose and duration of treatment. We therefore decided to do a systematic review of the literature on antibiotic treatment for spontaneous bacterial peritonitis. …