Observational case-control study of non-invasive ventilation in patients with ARDS.

BACKGROUND: The application of non-invasive pressure support ventilation (NIPSV) in patients with acute lung injury or ARDS remains controversial despite recent promising results. Data in rather homogeneous ARDS groups is lacking. OBJECTIVE: To compare the outcome of NIPSV-treated patients satisfying the diagnostic criteria for primary (pulmonary) ARDS (ARDSp) and presenting without distant organ failures at admission, with those of a matched control group treated in the same ICU with endotracheal mechanical ventilation (ETMV). METHODS: We applied NIPSV in 12 immunocompetent and collaborative patients who met the above cited criteria. NIPSV failure rate, short-term oxygenation, length of stay, mortality rate and complications were analyzed and compared with a control group of 12 intubated ARDSp-patients matched for age, SAPS II, PaO2/FiO2 and pH at admission. RESULTS: NIPSV failed in 4 patients developing distant organ failures. Compared to the ETMV control group, NIPSV success patients had reduced cumulative time on ventilation (p = 0.001) and length of ICU stay (p = 0.004). After the first 60' of ventilation, oxygenation improved more in the NIPSV than in the ETMV group (146 +/- 52 mmHg vs 109 +/- 34 mmHg; p = 0.05). The overall ICU mortality rate did not differ significantly between the groups but tended to be higher in the NIPSV group. CONCLUSIONS: In ARDSp patients without distant organ failures at admission and during the disease course, NIPSV might be a suitable alternative to invasive ventilation; however, the real effects on outcome of NIPSV applied to stable homogeneous subgroups of ARDS patients merit further investigations in randomised studies.

Influence of steroids on procalcitonin and C-reactive protein in patients with COPD and community-acquired pneumonia.

BACKGROUND: The induction of C-reactive Protein (CRP) may be attenuated by corticosteroids, whereas Procalcitonin (PCT) appears to be unaltered. We investigated, whether in community-acquired pneumonia (CAP) a combined antibiotic-corticosteroid therapy may actually lead to different slopes of decline of these inflammatory markers. PATIENTS AND METHODS: We studied the slopes of decline of PCT and CRP serum levels during 7 consecutive days as well as clinical parameters in a group of patients with CAP on or off corticosteroids. Patients with underlying COPD received systemic corticosteroids (n = 10), while non-COPD patients (n = 10) presenting with CAP alone formed the control group. All patients were treated with antibiotics. RESULTS: At baseline, relevant clinical and laboratory characteristics of the two groups were similar. Regarding the decreasing shapes of the curves from PCT and CRP, no significant differences were found (p-value = 0.48 for the groups for CRP, respectively 0.64 for PCT). All patients showed an uneventful recovery. CONCLUSION: In patients with COPD and CAP, the time courses over 7 days of PCT and CRP showed a nearly parallel decline compared to non-COPD patients with CAP. Contrary to the induction phase, corticosteroids do not modify the time-dependent decay of PCT and CRP when the underlying infectious disease (CAP) is adequately treated.

Systemic treatments for women with breast cancer: outcome with relation to screening for the disease.

Early detection and proper care of breast cancer are currently the best available approaches to the treatment of patients with the disease. In countries with a breast cancer screening programme, there has been a demonstrated reduction in breast cancer-related mortality. Such reduction has also been observed in Switzerland, a country in which no national programme of screening is available. Although there is no doubt that early diagnosis might have had a major role in reducing breast cancer mortality the magnitude of this effect is unknown. Research with tailored approaches on alternative imaging for early detection of breast cancer in high-risk women and on treatments offered according to proper criteria of responsiveness to therapies is warranted.

Noninvasive pressure support ventilation in non-COPD patients with acute cardiogenic pulmonary edema and severe community-acquired pneumonia: acute effects and outcome.

OBJECTIVE: To compare the acute effects of noninvasive pressure support ventilation (NIPSV) in non-COPD patients with acute cardiogenic pulmonary edema (CPE) and severe community-acquired pneumonia (CAP) presenting with a similar hypoxemic respiratory failure and exploring the ensuing impact on outcome. DESIGN. Prospective, observational study. SETTING. Multidisciplinary ICU, regional teaching hospital. PATIENTS: Non-COPD patients with CPE or severe CAP. MEASUREMENTS AND RESULTS: Fifteen patients with CPE and eighteen with CAP were included. Both groups had similar low PaO2/FiO2 ratios at admission; SAPS II, baseline pH(a) were lower in the CPE group than in the CAP group. Within the first NIPSV observation period (60 min), the oxygenation improved significantly in both CPE and CAP-groups; respiratory rate (RR) significantly decreased in the CPE group ( P=0.005), but it remained unchanged in the whole CAP group; heart rate and mean arterial pressure significantly decreased in both groups. One patient (6.6%) in the CPE group and seven patients (38%) in the CAP group were intubated ( P=0.04). The mean total time spent on NIPSV was 9.6+/-6.3 h in the CPE and 37.2+/-36 h in the CAP group ( P=0.01). Unit mortality rate was 6.6% in the CPE and 28% in the CAP group ( P=0.2). Upon inclusion, all but one CAP patients who were subsequently intubated had a bacteremic pneumonia; unit mortality rate was 57% in intubated- and 9% in non-intubated CAP patients ( P=0.05). CONCLUSIONS: NIPSV equally and rapidly improved oxygenation in non-COPD patients with CPE and severe CAP presenting with a similar hypoxemic respiratory failure, but the subsequent outcome was definitely different in the two groups, depending on the nature of the acute lung injury.

Severe pulmonary hypertension: data from the Swiss Registry.

BACKGROUND: Severe pulmonary hypertension (PH) is a rare disease with a dismal prognosis if untreated. Progress in diagnosis and in the development of effective therapeutic options has created new interest in this pathology. There are, however, only limited data on the prevalence of severe PH unrelated to chronic left ventricular failure or COPD, on the associated conditions and on the parameters with a prognostic impact. With the aid of a retrospective registry we have collected data from 5 centres in Switzerland and attempted to answer the above questions. METHODS: Data on patients with PH from 4 university facilities (Zurich, Basle, Geneva and Lausanne) and one well-defined geographical area (Ticino) were retrospectively collected and analysed up to December 1999. Clinical and haemodynamic parameters and associated diseases were noted. We were also interested in the age distribution of the patients and the year of diagnosis of PH. RESULTS: We found 106 patients with severe PH (43 men, 63 women, median age 43 years); 79% were in NYHA class III or IV. There was a steep rise in diagnosis of PH after 1995. In 74% PH was either primary or associated with collagen vascular disease or thromboembolic disease. By the end of the observation period 30% of the patients had died. The best distinguishing parameters between surviving patients and those who eventually died were the 6-minute walking test (363 vs. 235 metres, p = 0.002), the NYHA class (II vs III/IV, p = 0.015), and mixed venous saturation (66.5 vs. 57.9%, p = 0.006). Therapy consisted of calcium antagonists in 18% and of (inhaled) prostanoids, chiefly iloprost, in 33%. Seven patients underwent lung transplantation. CONCLUSIONS: We conclude that PH is diagnosed more often as diagnostic and therapeutic options improve; that primary forms, and those associated with collagen vascular disease and with chronic venous thromboembolism, make up three-quarters of the aetiologies; and that the 6-minute walking test, the functional class and mixed venous saturation are the best prognostic parameters.

Nebulized prostacyclin (PGI2) in acute respiratory distress syndrome: impact of primary (pulmonary injury) and secondary (extrapulmonary injury) disease on gas exchange response.

OBJECTIVES: To examine the hypothesis that the response to inhaled prostacyclin (PGI2 on oxygenation and pulmonary hemodynamics may be related to different morphologic features that are supposed to be present in acute respiratory distress syndrome (ARDS) originating from pulmonary (primary ARDS [ARDS(PR)]) and from extrapulmonary disease (secondary ARDS [ARDS(SEC)]). DESIGN: Prospective, nonrandomized interventional study. SETTING: Multidisciplinary intensive care unit, secondary care center. PATIENTS: Fifteen consecutive, mechanically ventilated patients with ARDS and severe hypoxemia, defined as PaO2/FIO2 of <150 torr at the time of admission. INTERVENTIONS: After an initial stable period of at least 60 mins, patients received nebulized PGI2 in 15-min steps; the drug was titrated to find the dose with the best improvement of PaO2, starting with 2 ng/kg/min up to an allowed maximum dose of 40 ng/kg/min. MEASUREMENTS AND MAIN RESULTS: Blood gas, gas exchange, and hemodynamic measurements were performed at the following time points: a) baseline; b) during the optimal or maximum dose of PGI2; and c) 1 hr after withdrawal of the drug. Patients underwent a computed tomographic (CT) scan using a basal CT section to compute the mean CT numbers and the density histogram. Patients were considered responders to PGI2 if an increase in PaO2 of > or =7.5 torr or an increase in PaO2/FIO2 ratio of > or =10% occurred. For the group as a whole, mean pulmonary artery pressure decreased from 32 +/- 1 to 29 +/- 1 mm Hg during PGI2 nebulization, whereas pulmonary vascular resistance decreased 1 hr after withdrawal of nebulization from 177 +/- 18 to 153 +/- 16 dyne x sec/cm5; oxygenation did not change significantly. Eight patients responded to PGI2 nebulization on oxygenation (all were in the ARDS(SEC) subgroup), whereas seven did not (all but one were in the ARDS(PR) subgroup). Among the physiologic variables examined to assess any difference between the two ARDS groups at time of PGI2 nebulization, there was a significant difference concerning the mean CT density number, which was -445 +/- 22 Hounsfield Units in the ARDS(SEC) group and -258 +/- 16 Hounsfield Units in the ARDS(PR) group. In patients presenting with an ARDS(PR), PGI2 induced a reduction in PaO2/FIO2 and a reduction in PaO2 from 87 +/- 2 to 79 +/- 2 torr, whereas in patients with an ARDS(SEC) there was an increase in PaO2/FIO2 and in PaO2 from 76 +/- 4 to 84 +/- torr with a decrease in mean pulmonary artery pressure. CONCLUSIONS: Based on the data from this study, the clinical recognition of the two types of the syndrome together with the CT number frequency distribution analysis may be associated with a prediction of the PGI2 nebulization response on oxygenation.

Health effects of job insecurity among employees in the Swiss general population.

This study looks at the health consequences of the social distress caused by perceived levels of job insecurity. Through interviews with full- and part-time employees drawn from a random sample (N = 2,024) of the Swiss general population, the authors measured prevalence rates of ten self-reported indicators of health and health-related behavior according to three levels of perceived job insecurity (low, middle, high), and estimated odds ratios using logistic regression adjusted for relevant respondent characteristics. The results show that the psychosocial stress induced by job insecurity (fear of unemployment) has a negative effect on these health indicators. Fear of unemployment had a stronger unfavorable effect on health for highly educated employees than for the less educated. The authors make some recommendations for raising awareness about the health effects of job insecurity and taking these effects into account in policies and legislation affecting the labor market and work environment.

Mass media interventions: effects on health services utilisation.

BACKGROUND: The mass media frequently cover health related topics, are the leading source of information about important health issues, and are targeted by those who aim to influence the behaviour of health professionals and patients. OBJECTIVES: To assess the effects of mass media on the utilisation of health services. SEARCH STRATEGY: We searched the Cochrane Effective Practice and Organisation of Care Group specialised register, MEDLINE, EMBASE, Eric, PsycLit, and reference lists of articles. We hand searched the journals Communication Research (February 1987 to August 1996), European Journal of Communication (1986 to 1994), Journal of Communication (winter 1986 to summer 1996), Communication Theory (February 1991 to August 1996), Critical Studies in Mass Communication (March 1984 to March 1995) and Journalism Quarterly (1986 to summer 1996). SELECTION CRITERIA: Randomised trials, controlled clinical trials, controlled before-and-after studies and interrupted time series analyses of mass media interventions. The participants were health care professionals, patients and the general public. DATA COLLECTION AND ANALYSIS: Two reviewers independently extracted data and assessed study quality. MAIN RESULTS: Seventeen studies were included. All used interrupted time series designs. Fourteen evaluated the impact of formal mass media campaigns, and three of media coverage of health related issues. The overall methodological quality was variable. Six studies did not perform any statistical analysis, and seven used inappropriate statistical tests (ie not taking into account the effect of time trend). All of the studies apart from one concluded that mass media was effective. These positive findings were confirmed by our re-analysis in seven studies. The direction of effect was consistent across studies towards the expected change. The pooled effect sizes for studies assessing the impact of mass media on similar aspects of care revealed an effect upon the utilisation of health services that could not be explained by chance alone, ranging from -1.96 (95%CI -1. 19 to -2.73) for campaigns promoting immunisation programmes, to -1. 12 (95%CI -0.49 to -2.36) for those concerning cancer screening. REVIEWER'S CONCLUSIONS: Despite the limited information about key aspects of mass media interventions and the poor quality of the available primary research, there is evidence that these channels of communication may have an important role in influencing the use of health care interventions. Those engaged in promoting better uptake of research information in clinical practice should consider mass media as one of the tools that may encourage the use of effective services and discourage those of unproven effectiveness.

Occupational exposure to inhalative irritants and methacholine responsiveness.

OBJECTIVES: Occupational exposures to inhalative irritants have been associated with an increased reporting of respiratory symptoms in previous studies. Methacholine responsiveness represents a continuous measure of airway responsiveness. As such, it may be less subject to recall bias and more sensitive to detecting effects of occupational exposure on airways. Such effects may be stronger among atopic persons. The objective of the study was to examine the relationship between self-reports of occupational exposure to dusts, gases, vapors, aerosols, and fumes and methacholine responsiveness. METHODS: A sample was studied of never smokers (N=3044) chosen randomly from 8 areas in Switzerland. Atopy was defined as any positive skin test to 8 inhalative allergens. Nonspecific bronchial reactivity was tested using methacholine chloride and quantified by calculating the slope of the dose-response. RESULTS: The methacholine slopes were 19% [95% confidence interval (95% CI) 6-32] higher for never smokers with exposure to dusts, fumes, vapors, gases, or aerosols than for the unexposed group. When only atopic never smokers were examined. the increase was larger (37%, 95% CI 7-75), and for persons with >2 positive skin prick tests the effect was still higher (42%, 95% CI -1.5-104). Exposure to vapors and aerosols was strongly associated with increased methacholine slopes among the atopic subjects. CONCLUSIONS: Occupational exposure, particularly to dusts and fumes, was associated with increased bronchial reactivity in never smokers in this study. The magnitude of the effect was larger among atopic subjects.

Sustained improvement of performance and haemodynamics with long-term aerosolised prostacyclin therapy in severe pulmonary hypertension.

Primary pulmonary hypertension and pulmonary hypertension associated with collagen vascular disease or HIV infection are rapidly progressive fatal diseases in spite of conventional medical therapy. Continuous intravenous infusion of prostacyclin has been shown to prolong life in severe primary pulmonary hypertension, and aerosolised prostacyclin has been used successfully on a short-term basis in patients with pulmonary hypertension. We investigated the effects of acute administration of aerosolised prostacyclin or its analogue iloprost in 5 patients with severe pulmonary hypertension; 4 of these patients were followed over a period of 7 months. On acute testing, mean pulmonary artery pressure decreased from 59 to 46 mm Hg (p = 0.01); echocardiographically estimated systolic pulmonary pressure further declined from 66 mm Hg after 2 days' treatment to 54 mm Hg after 7 months (p = 0.03). Symptom-limited walking distance significantly improved from 42 to 87 m after 2 days' treatment (p = 0.003); a further 2- to 8-fold increase was observed in single patients during follow-up. In severe pulmonary hypertension, aerosolised prostacyclin or iloprost improves exercise capacity and lowers pulmonary artery pressure beyond the level achieved on acute exposure.

Long-term ambient air pollution and respiratory symptoms in adults (SAPALDIA study). The SAPALDIA Team.

The association between long-term exposure to ambient air pollution and respiratory symptoms was investigated in a cross-sectional study in random population samples of adults (aged 18 to 60 yr, n = 9,651) at eight study sites in Switzerland. Information on respiratory symptoms was obtained with an extended version of the European Community Respiratory Health Survey questionnaire. The impact of annual mean concentrations of air pollutants was analyzed separately for never-, former, and current smokers. After controlling for age, body mass index, gender, parental asthma, parental atopy, low education, and foreign citizenship, we found positive associations between annual mean concentrations of NO2, total suspended particulates, and particulates of less than 10 micrometers in aerodynamic diameter (PM10) and reported prevalences of chronic phlegm production, chronic cough or phlegm production, breathlessness at rest during the day, breathlessness during the day or at night, and dyspnea on exertion. We found no associations with wheezing without cold, current asthma, chest tightness, or chronic cough. Among never-smokers, the odds ratio (95% confidence interval) for a 10 micrograms/ m3 increase in the annual mean concentration of PM10 was 1. 35 (1.11 to 1.65) for chronic phlegm production, 1.27 (1.08 to 1.50) for chronic cough or phlegm production, 1.48 (1.23 to 1.78) for breathlessness during the day, 1.33 (1.14 to 1.55) for breathlessness during the day or at night, and 1.32 (1.18 to 1.46) for dyspnea on exertion. No associations were found with annual mean concentrations of O3. Similar associations were also found for former and current smokers, except for chronic phlegm production. The observed associations remained stable when further control was applied for environmental tobacco smoke exposure, past and current occupational exposures, atopy, and early childhood respiratory infections when restricting the analysis to long-term residents and to non- alpine areas, and when excluding subjects with physician-diagnosed asthma. The high correlation between the pollutants makes it difficult to sort out the effect of one single pollutant. This study provides further evidence that long-term exposure to air pollution of rather low levels is associated with higher prevalences of respiratory symptoms in adults.

[Therapeutic use of N-acetylcysteine in acute lung diseases]. / Utilisation thérapeutique de la N-acétylcystéine au cours des agressions pulmonaires aiguës.

Oxidants play a key role in disease processes, particularly in the detrimental mechanisms leading to tissue damage in certain forms of acute lung injury. A number of mediators contribute to the pathologic response in ARDS, SIRS or hyperoxia-induced pulmonary damage. One of the most important detrimental factors is the generation and activation of highly reactive oxygen species which are leading factors implicated in the process of tissue damage. N-acetylcysteine (NAC) is a free radical scavenger and might access the endothelial cell thus increasing intracellular glutathione (GSH) stores. Different studies have demonstrated that NAC might be a promising compound either for the prevention or the treatment of acute lung damages such as ARDS. However, the true beneficial effect so far reported in several clinical and experimental studies contrasts with some contradictory and intriguing aspects, probably because the significance of a direct in vivo antioxidative effect of this compound remains to be established in humans. Thus, the mode of action of NAC may not be the same in different pathologies and clinical situations. More research into the mechanisms of action of this unique xenobiotic substance may offer a clue for elucidating these controversies.

[Impact of mass media on the use of health services. A systematic review of the literature]. / L'effetto dei mass media sull'uso dei servizi sanitari. Una revisione sistematica della letteratura.

BACKGROUND: Mass media may influence the use of health services either through campaigns promoting the use of specific procedures or through the coverage of health related issues outside the context of a planned intervention. To assess their effect on the utilization of health services a systematic overview of primary research was undertaken. METHODS: Experimental and quasi experimental studies meeting pre defined entry criteria and providing information on the impact of mass media on objective measures on health services utilization were searched through Medline, Embase, Psychlit, Eric, as well as handsearching key journals. Data on the detail and content of interventions were abstracted and raw data describing health services utilization obtained. Effect sizes were calculated for each study and then pooled across studies on the same topic using a random effects model. RESULTS: Out of 69 papers providing information on the impact of mass media on aspects of health services utilization, 17 interrupted time series met our quality criteria. Fourteen evaluated the impact of formal mass media campaigns, 3 of media coverage of health related issues. The overall methodological quality was rather variable, with 6 studies not performing any statistical analysis, and 7 using inadequate statistical tests (i.e. not taking into account the effect of time trend). All the studies but the concluded positively on the effect of mass media. These positive findings were confirmed by our re-analysis in 7, while in the remaining the effect of mass media was not statistically significant. The direction of effect was consistent across individual studies and the pooled effect sizes revealed an effect upon the utilization of health services that could not be explained by chance alone, ranging from -1.96 (95% CI: -1.19, -2.73) for campaigns promoting immunization programs, to -1.12 (95% CI: -0.49, -2.46) for those concerning cancer screening. CONCLUSIONS: Despite the overall limited quality of primary research, this review supports the view that these channels of communication may have an important role in influencing the use of health care interventions. Mass media should be considered as one of the tools that may encourage the use of effective services and discourage those of unproved effectiveness.

[Incidence of operations in Switzerland related to insurance status]. / Die Häufigkeit von Operationen in der Schweiz nach Versicherungsstatus.

Several studies reported in the literature show that surgical procedures can be carried out for other than clinical indications. In Switzerland, no statistics on the "demography" of surgical procedures are available. But an earlier analysis of the "Swiss Health Survey 1992/93" gave first indications on differences in rates of surgical procedures (hysterectomy, appendectomy, tonsillectomy and operation of the hip and gallbladder) by sex, educational status and region. This study, based on the same datasource (N = 10792), reveals an additional link with the health insurance status. The prevalence of surgical procedures is higher in privately insured than in persons with only basic insurance, independent of age, sex and region. The highest rates of surgical procedures (except tonsillectomy) are found among privately insured persons with a low educational status. Among 25-74 year old privately insured women, the lifetime-prevalence of a hysterectomy is 30% with low and 13% with high educational status (p < .001). The corresponding prevalences of at least one of the mentioned surgical procedures (without tonsillectomy) are 49% versus 28% (p < .001). As these are lifetime-prevalences, these rates do not necessarily reflect the actual surgical procedures. However, an analysis of the period of operation for hysterectomy and for the gallbladder shows the same pattern as the mentioned lifetime-prevalences. Higher rates among privately insured are also a frequent finding in the international literature. These findings should stimulate patients to ask for a "second opinion". Furthermore, there is an urge for the implementation of general hospital statistics to verify such findings. In addition, the scientific consensus on the indication of several surgical procedures should be promoted on the way to more evidence-based-medicine.

Associations between lung function and estimated average exposure to NO2 in eight areas of Switzerland. The SAPALDIA Team. Swiss Study of Air Pollution and Lung Diseases in Adults.

In this paper, we present results from the SAPALDIA study (Swiss Study on Air Pollution and Lung Diseases in Adults) regarding associations between lung function [forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1)], as assessed during the cross-sectional study in 1991, and average levels of NO2 exposure within the eight study communities. We distinguished average home outdoor exposure and average personal exposure to NO2 and obtained exposure estimates by computing regional averages of passive sampler measurements performed by a random subsample of SAPALDIA participants in 1993. Previous analyses had revealed associations between average lung function and average air pollution levels between communities. The present results show that such associations may also be seen within communities: a 10-micrograms per m3 increase in average home outdoor and personal exposure to NO2 between zones of residence of the same community was associated with a change in average FVC by -0.59% [95% confidence limits (CL) = 0.01, -1.19] and -0.74% (95% CL = -0.07, -1.41), respectively. These values, however, are smaller than the ones found for the corresponding associations between study communities: -1.67% (95% CL = -1.01, -2.33) and -2.93% (95% CL = -2.11, -3.75), respectively. The different magnitudes of these two types of associations might be explained by differences in spatial variation between various components of air pollution.

[Swiss Study on Air Pollution and Lung Diseases in Adults (SAPALDIA)]. / Etude suisse sur la pollution de l'air et les maladies respiratoires chez l'adulte (SAPALDIA). Swiss Study on Air Pollution and Lung Diseases in Adults.

Long-term health effects of moderate ambient air pollution are rarely investigated. In Switzerland, no large-scale study has addressed this issue so far. Important results of the Swiss Study on Air Pollution and Lung Disease in Adults (SAPALDIA) are presented. During the period 1991-1993, SAPALDIA investigated a random population sample (18-60 years) in eight Swiss areas with different environmental characteristics (Aarau, Basel, Davos, Geneva, Lugano, Montana, Payerne, Wald). In total, 9651 adults (60%) participated in the cross-sectional investigation (part 1, 1991), consisting of the following standardized procedures: questionnaire (interview), forced expiratory lung function test, bronchial challenge with methacholine, atopy assessment (Phadiatop, unspecific total IgE), allergy skin tests, and endexpiratory CO-measurements. Subjects with a history of respiratory symptoms, increased bronchial reactivity, reduced lung function (FEV1/FVC < 80% predicted) and 150 healthy never-smokers were included in the subsequent diary study (part 2; n = 3281, 1992/93). Peak flow (morning and evening), symptoms, medication, personal activity and visits to the doctor were monitored. Across regions, annual mean values ranged from 9 to 52 mg/m3 (NO2) and 10 to 33 mg/m3 (PM10) respectively. Air pollution had effects on prevalence of dyspnea (+41% per 10 mg/m3 increment of the annual mean PM10, 95% CI 20-65%), on symptoms of chronic bronchitis (+31%, 10-55%), on FVC (-3.1%; -3.7 to -2.6%), and FEV1 (-1.1%; -1.7% to -0.5%), on the incidence of respiratory symptoms and the length of symptomfree intervals (11% change per 10 mg/m3 PM10), but not on the prevalence of asthma. Environmental tobacco smoke (ETS) showed impact on wheezing (OR 1.94; 1.39-2.70), asthma (1.39; 1.04-1.86), bronchitis (1.60; 1.24-2.08) and chronic bronchitis (1.50; 1.11-2.02). Health effects of moderate air pollution were confirmed in Switzerland. Although for the individual the relative risks are small, the public health impact may be considerable. An ongoing follow-up will investigate the mortality profile of the SAPALDIA cohort.

Promoting consumers' demand for evidence-based medicine.

The widespread implementation of rationing and priority-setting policies in health care opposes the stochastic practice of medicine induced by professional uncertainty and professional vested interests in market-oriented clinical environments. It also clashes with consumers' overly optimistic and "mythical" view of the effectiveness of medicine, which is bound to support a potentially unlimited provision of health services. Thus, for consumers and society at large, it is necessary to create conditions favorable for a more conscious demand of evidence-based health care. In pursuit of this goal, we suggest the adoption of a community-oriented strategy based upon delivery of information to the public in order a) to generate greater awareness ("healthy skepticism") among consumers, through disclosure of data on the true effectiveness of health care interventions and on the existing variation in their utilization, and b) to provide tools to empower consumers in dealing better with both the uncertainty in their own individual patient-physician relationships and with the health policy issues to be faced in the future. Such a community-oriented strategy could also reinforce and support, through the generation of a "bottom-up" pressure from consumers toward physicians, a wider adoption of evidence-based interventions by health care professionals. This paper, using data from surveys on public opinions and attitudes toward the practice of medicine, focuses on how consumer demand for more evidence-based medical practice can be promoted.