Assessment of the COOP charts with and without pictures in a Swiss population.

OBJECTIVES: This study aimed to assess the validity of COOP charts in a general population sample, to examine whether illustrations contribute to instrument validity, and to establish general population norms. METHODS: A general population mail survey was conducted among 20-79 years old residents of the Swiss canton of Vaud. Participants were invited to complete COOP charts, the SF-36 Health Survey; they also provided data on health service use in the previous month. Two thirds of the respondents received standard COOP charts, the rest received charts without illustrations. RESULTS: Overall 1250 persons responded (54%). The presence of illustrations did not affect score distributions, except that the illustrated 'physical fitness' chart drew greater non-response (10 vs. 3%, p < 0.001). Validity tests were similar for illustrated and picture-less charts. Factor analysis yielded two principal components, corresponding to physical and mental health. Six COOP charts showed strong and nearly linear relationships with corresponding SF36 scores (all p < 0.001), demonstrating concurrent validity. Similarly, most COOP charts were associated with the use of medical services in the past month. Only the chart on 'social support' partly deviated from construct validity hypotheses. Population norms revealed a generally lower health status in women and an age-related decline in physical health. CONCLUSIONS: COOP charts can be used to assess the health status of a general population. Their validity is good, with the possible exception of the 'social support' chart. The illustrations do not affect the properties of this instrument.

Accuracy of four cardiovascular risk scores in a Swiss population-based cohort

Purpose: To assess the global cardiovascular (CV) risk of an individual, several scores have been developed. However, their accuracy and comparability need to be evaluated in populations others from which they were derived. The aim of this study was to compare the predictive accuracy of 4 CV risk scores using data of a large population-based cohort. Methods: Prospective cohort study including 4980 participants (2698 women, mean age± SD: 52.7±10.8 years) in Lausanne, Switzerland followed for an average of 5.5 years (range 0.2 - 8.5). Two end points were assessed: 1) coronary heart disease (CHD), and 2) CV diseases (CVD). Four risk scores were compared: original and recalibrated Framingham coronary heart disease scores (1998 and 2001); original PROCAM score (2002) and its recalibrated version for Switzerland (IAS-AGLA); Reynolds risk score. Discrimination was assessed using Harrell's C statistics, model fitness using Akaike's information criterion (AIC) and calibration using pseudo Hosmer-Lemeshow test. The sensitivity, specificity and corresponding 95% confidence intervals were assessed for each risk score using the highest risk category ([20+ % at 10 years) as the "positive" test. Results: Recalibrated and original 1998 and original 2001 Framingham scores show better discrimination (>0.720) and model fitness (low AIC) for CHD and CVD. All 4 scores are correctly calibrated (Chi2<20). The recalibrated Framingham 1998 score has the best sensitivities, 37.8% and 40.4%, for CHD and CVD, respectively. All scores present specificities >90%. Framingham 1998, PROCAM and IAS-AGLA scores include the greatest proportion of subjects (>200) in the high risk category whereas recalibrated Framingham 2001 and Reynolds include <=44 subjects. Conclusion: In this cohort, we see variations of accuracy between risk scores, the original Framingham 2001 score demonstrating the best compromise between its accuracy and its limited selection of subjects in the highest risk category. We advocate that national guidelines, based on independently validated data, take into account calibrated CV risk scores for their respective countries.

La mortalité par tumeur maligne chez les ouvriers d'une fabrique de caoutchouc en Suisse: étude épidémiologique, 1955-1975. [Cancer mortality among the workers of a Swiss rubber goods factory. Epidemiological study, 1955-75].

In an epidemiologic investigation of mortality among workers in a Swiss rubber-goods factory the cancer mortality in the period 1955-1975 has been studied in all male workers active on 1 January 1955 in (a) a rubber-goods factory and (b) a munitions factory, the latter as reference population. The two groups numbered some 1000 each. Both factories were located in the same Central Swiss village where no other industry was present. Mortality in each industry is compared with that in the Swiss population in general (SMR) and the mortalities of the two industries are compared with each other. The results tend to confirm that rubber workers are exposed to a higher risk of cancer mortality. Three particular types of cancer are briefly discussed: cancer of the stomach, of the lower urinary tract, and glioblastoma.

Swiss DRGs : patient heterogeneity and hospital payments

In this paper, we analyze the prospective method of paying hospitals when the within-DRG variance is high. To avoid patients dumping, an outlier payment system is implemented. In the APDRG Swiss System, it consists in a mixture of fully prospective payments for low costs patients and partially cost-based system for high cost patients. We show how the optimal policy depends on the degree to which hospitals take patients' interest into account. A fixed-price policy is optimal when the hospital is sufficiently benevolent. When the hospital is weakly benevolent, a mixed policy solving a trade-off between rent extraction, efficiency and dumping deterrence must be preferred. Following Mougeot and Naegelen (2008), we show how the optimal combination of fixed price and partially costbased payment depends on the degree of benevolence of the hospital, the social cost of public funds and the distribution of patients severity. [Authors]

Lipodystrophy and weight changes: data from the Swiss HIV Cohort Study, 2000-2006.

BACKGROUND AND OBJECTIVES: Combination antiretroviral therapy (cART) is changing, and this may affect the type and occurrence of side effects. We examined the frequency of lipodystrophy (LD) and weight changes in relation to the use of specific drugs in the Swiss HIV Cohort Study (SHCS). METHODS: In the SHCS, patients are followed twice a year and scored by the treating physician as having 'fat accumulation', 'fat loss', or neither. Treatments, and reasons for change thereof, are recorded. Our study sample included all patients treated with cART between 2003 and 2006 and, in addition, all patients who started cART between 2000 and 2003. RESULTS: From 2003 to 2006, the percentage of patients taking stavudine, didanosine and nelfinavir decreased, the percentage taking lopinavir, nevirapine and efavirenz remained stable, and the percentage taking atazanavir and tenofovir increased by 18.7 and 22.2%, respectively. In life-table Kaplan-Meier analysis, patients starting cART in 2003-2006 were less likely to develop LD than those starting cART from 2000 to 2002 (P<0.02). LD was quoted as the reason for treatment change or discontinuation for 4% of patients on cART in 2003, and for 1% of patients treated in 2006 (P for trend <0.001). In univariate and multivariate regression analysis, patients with a weight gain of >or=5 kg were more likely to take lopinavir or atazanavir than patients without such a weight gain [odds ratio (OR) 2, 95% confidence interval (CI) 1.3-2.9, and OR 1.7, 95% CI 1.3-2.1, respectively]. CONCLUSIONS: LD has become less frequent in the SHCS from 2000 to 2006. A weight gain of more than 5 kg was associated with the use of atazanavir and lopinavir.

One-year prevalence of low back pain in two Swiss regions: estimates from the population participating in the 1992-1993 MONICA project.

STUDY DESIGN: A cross-sectional survey was performed. OBJECTIVE: To estimate the extent of low back pain as a public health problem. SUMMARY OF BACKGROUND DATA: Health surveys converge on very high estimates of low back pain in general populations, but few studies have included severity criteria in their definition and conclusions. Because it is unlikely that interventions will influence the prevalence of minimal and infrequent symptoms, greater attention should be paid to characteristics of low back pain that indicate some impact on the life of survey respondents. METHODS: Two regions participated in the MONICA (MONitoring of trends and determinants in CArdiovascular disease) project in Switzerland. Participants randomly selected from the general population completed a standard self-administered questionnaire on cardiovascular risk factors. A special section on low back pain was added in the third (1992-1993) MONICA survey and completed by 3227 participants. RESULTS: A regional difference found in the 12-month prevalence rate disappeared with the inclusion of severity criteria. Low back pain over more than seven cumulated days was reported among men by 20.2% (age range, 25-34 years) to 28.5% (age range, 65-74 years), respectively, among women by 31.1% to 38.5%. Similar rates of reduction in activity (professional, housekeeping, and leisure time) and medical consultation (conventional and nonconventional) motivated by low back pain characterized the two participating regions. The cumulative duration of pain was related to all the indicators showing the impact of low back pain on everyday life. CONCLUSIONS: Determining the cumulative duration of low back pain over the preceding year is a straightforward task, and a cutoff at 1 week seems appropriate for distinguishing between low- and high-impact low back pain.

Efficacy, tolerability and risk factors for virological failure of darunavir-based therapy for treatment-experienced HIV-infected patients: the Swiss HIV Cohort Study.

OBJECTIVES: Darunavir was designed for activity against HIV resistant to other protease inhibitors (PIs). We assessed the efficacy, tolerability and risk factors for virological failure of darunavir for treatment-experienced patients seen in clinical practice. METHODS: We included all patients in the Swiss HIV Cohort Study starting darunavir after recording a viral load above 1000 HIV-1 RNA copies/mL given prior exposure to both PIs and nonnucleoside reverse transcriptase inhibitors. We followed these patients for up to 72 weeks, assessed virological failure using different loss of virological response algorithms and evaluated risk factors for virological failure using a Bayesian method to fit discrete Cox proportional hazard models. RESULTS: Among 130 treatment-experienced patients starting darunavir, the median age was 47 years, the median duration of HIV infection was 16 years, and 82% received mono or dual antiretroviral therapy before starting highly active antiretroviral therapy. During a median patient follow-up period of 45 weeks, 17% of patients stopped taking darunavir after a median exposure of 20 weeks. In patients followed beyond 48 weeks, the rate of virological failure at 48 weeks was at most 20%. Virological failure was more likely where patients had previously failed on both amprenavir and saquinavir and as the number of previously failed PI regimens increased. CONCLUSIONS: As a component of therapy for treatment-experienced patients, darunavir can achieve a similar efficacy and tolerability in clinical practice to that seen in clinical trials. Clinicians should consider whether a patient has failed on both amprenavir and saquinavir and the number of failed PI regimens before prescribing darunavir.

Iron Supplementation Therapy in a Large Swiss Cohort of Inflammatory Bowel Disease Patients: Shift from Oral to Intravenous Therapy over Time

Background a nd A ims: T he 2 007 ECCO g uidelines o nanemia in inflammatory bowel disease (IBD) favour intravenous(iv) over oral (po) i ron supplementation due to bettereffectiveness and tolerance. Application of guidelines in clinicalpractice m ay r equire time. We a imed to determine thepercentage of IBD patients under iron supplementation therapyand its application mode over time in a large IBD cohort.Methods: Helsana, a leading Swiss health insurance companyprovides c overage f or approximately 18% of t he Swisspopulation, corresponding to about 1.2 million enrollees.Patients with Crohn's disease (CD) and ulcerative colitis (UC)were identified b y keyword search from t he a nonymisedHelsana database.Results: I n total, 6 29 CD ( 61% female) a nd 4 03 UC ( 56%female) patients w ere identified, mean retrospectiveobservation time w as 2 0.4 m onths f or CD and 13 m onths f orUC patients. Of t he entire study population, 29.3% wereprescribed iron. O ccurrence of iron prescription was 21.3% inmales a nd 31.2% in f emales ( odds r atio [OR] 1 .69, 95%-confidence interval [CI] 1.26-2.28). The prescription of iv i ronincreased from 2006/2007 ( 48.8% w ith iv i ron) to 2 008/2009(65.2% with iv iron) by a factor of 1.89.Conclusions: One third of the IBD population was treated withiron supplementation. A gradual s hift from oral t o iv iron wasobserved over time in a large Swiss IBD cohort. This switch inprescription habits g oes a long with the implementation of theECCO consensus guidelines on anemia in IBD.

Analysis and spatial modeling of the indoor radon Swiss data

The present research deals with an important public health threat, which is the pollution created by radon gas accumulation inside dwellings. The spatial modeling of indoor radon in Switzerland is particularly complex and challenging because of many influencing factors that should be taken into account. Indoor radon data analysis must be addressed from both a statistical and a spatial point of view. As a multivariate process, it was important at first to define the influence of each factor. In particular, it was important to define the influence of geology as being closely associated to indoor radon. This association was indeed observed for the Swiss data but not probed to be the sole determinant for the spatial modeling. The statistical analysis of data, both at univariate and multivariate level, was followed by an exploratory spatial analysis. Many tools proposed in the literature were tested and adapted, including fractality, declustering and moving windows methods. The use of Quan-tité Morisita Index (QMI) as a procedure to evaluate data clustering in function of the radon level was proposed. The existing methods of declustering were revised and applied in an attempt to approach the global histogram parameters. The exploratory phase comes along with the definition of multiple scales of interest for indoor radon mapping in Switzerland. The analysis was done with a top-to-down resolution approach, from regional to local lev¬els in order to find the appropriate scales for modeling. In this sense, data partition was optimized in order to cope with stationary conditions of geostatistical models. Common methods of spatial modeling such as Κ Nearest Neighbors (KNN), variography and General Regression Neural Networks (GRNN) were proposed as exploratory tools. In the following section, different spatial interpolation methods were applied for a par-ticular dataset. A bottom to top method complexity approach was adopted and the results were analyzed together in order to find common definitions of continuity and neighborhood parameters. Additionally, a data filter based on cross-validation was tested with the purpose of reducing noise at local scale (the CVMF). At the end of the chapter, a series of test for data consistency and methods robustness were performed. This lead to conclude about the importance of data splitting and the limitation of generalization methods for reproducing statistical distributions. The last section was dedicated to modeling methods with probabilistic interpretations. Data transformation and simulations thus allowed the use of multigaussian models and helped take the indoor radon pollution data uncertainty into consideration. The catego-rization transform was presented as a solution for extreme values modeling through clas-sification. Simulation scenarios were proposed, including an alternative proposal for the reproduction of the global histogram based on the sampling domain. The sequential Gaussian simulation (SGS) was presented as the method giving the most complete information, while classification performed in a more robust way. An error measure was defined in relation to the decision function for data classification hardening. Within the classification methods, probabilistic neural networks (PNN) show to be better adapted for modeling of high threshold categorization and for automation. Support vector machines (SVM) on the contrary performed well under balanced category conditions. In general, it was concluded that a particular prediction or estimation method is not better under all conditions of scale and neighborhood definitions. Simulations should be the basis, while other methods can provide complementary information to accomplish an efficient indoor radon decision making.

La cohorte sepsis lausannoise: une opportunité de développer la recherche dans le Réseau latin de médecine intensive [Lausanne Cohort of septic patients as an opportunity to develop multidisciplinary research within the Swiss Latin Network of Intensive Care Medicine]

Despite recent medical progresses in patient support, the mortality of sepsis remains high. Recently, new supporting strategies were proposed to improve outcome. Whereas such strategies are currently considered as standard of care, their real impact on mortality, morbidity, length of stay, and hence, health care resources utilization has been only weakly evaluated so far. Obviously, there is a critical need for epidemiologic surveys of sepsis to better address these major issues. The Lausanne Cohort of septic patients aims at building a large clinical, biological and microbiological database that will be used as a multidisciplinary research platform to study the various pathogenic mechanisms of sepsis in collaboration with the various specialists. This could be an opportunity to strengthen the collaboration within the Swiss Latin network of Intensive Care Medicine.