781 resultados para design-based survey sampling
Resumo:
Organic acids play an important role in the nutritional conditions of plants. Their relevance is related to their formation dynamics, mineralization rate and adsorption by soil colloids. This study was carried out to evaluate the dynamics of mineralization and adsorption of organic acid (acetic acid - AA, citric acid - CA and humic acid - HA) applied to the soil. Samples of two Oxisols were used: Rhodic Haplustox (LV) and Typic Haplustox (LVA). The mineralization experiment was arranged in a 2 x 3 x 5 factorial design, based on the factors: two soils (LV and LVA) x three organic acid (OA) types (AA, CA and HA) x five OA rates (0, 1, 2, 4, and 8 mmol dm-3). Organic carbon mineralization in samples was measured by the C-CO2 efflux, produced by the microbial activity, in a 30-day (measurements after 4, 8, 12, 21, and 30 days) and in a 4-day experiment (measured after 24, 48, 72 and 96 h). Organic acid adsorption was tested in a 2 x 2 x 5 x 4 factorial design, with the factors and levels: two Oxisols; two organic acids (AA and CA); five OA rates (0, 1, 2, 4, and 8 mmol dm-3) and four adsorption periods (6, 24, 48, and 72 h). The C-CO2 production of soil treated with CA was highest. In the adsorption experiment, the affinity of CA to soil adsorption sites was greatest. The adsorption of organic acids to soils may be an important mechanism by which bioavailability and thus mineralization capacity by microbial activity are reduced.
Resumo:
The occurrence of cardiovascular diseases (CVD) and related risk factors was evaluated in Seychelles, a middle level income country, as accumulating evidence supports increasing rates of CVD in developing countries. CVD mortality was obtained from vital statistics for two periods, 1984-5 and 1991-3. CVD morbidity was estimated by retrospective review of discharge diagnoses for all admissions to medical wards in 1990-1992. Levels of CVD risk factors in the population were assessed in 1989 through a population-based survey. In 1991-93, standardized mortality rates were in males and females respectively, 80.9 and 38.8 for cerebrovascular disease and 92.9 and 47.0 for ischemic heart disease. CVD accounted for 25.2% of all admissions to medical wards. Among the general population aged 35-64, 30% had high blood pressure, 52% of males smoked, and 28% of females were obese. These findings substantiate the current health transition to CVD in Seychelles. More generally, epidemiologic data on CVD mortality, morbidity, and related risk factors, as well as similar indicators for other chronic diseases, should more consistently appear in national and international reports of human development to help emphasize, in the health policy making scene, the current transition to chronic diseases in developing countries and the subsequent need for appropriate control and prevention programs.
Resumo:
ABSTRACT The impact of intensive management practices on the sustainability of forest production depends on maintenance of soil fertility. The contribution of forest residues and nutrient cycling in this process is critical. A 16-year-old stand of Pinus taeda in a Cambissolo Húmico Alumínico léptico (Humic Endo-lithic Dystrudept) in the south of Brazil was studied. A total of 10 trees were sampled distributed in five diameter classes according to diameter at breast height. The biomass of the needles, twigs, bark, wood, and roots was measured for each tree. In addition to plant biomass, accumulated plant litter was sampled, and soil samples were taken at three increments based on sampling depth: 0.00-0.20, 0.20-0.40, 0.40-0.60, 0.60-1.00, 1.00-1.40, 1.40-1.80, and 1.80-1.90 m. The quantity and concentration of nutrients, as well as mineralogical characteristics, were determined for each soil sample. Three scenarios of harvesting intensities were simulated: wood removal (A), wood and bark removal (B), and wood + bark + canopy removal (C). The sum of all biomass components was 313 Mg ha-1.The stocks of nutrients in the trees decreased in the order N>Ca>K>S>Mg>P. The mineralogy of the Cambissolo Húmico Alumínico léptico showed the predominance of quartz sand and small traces of vermiculite in the silt fraction. Clay is the main fraction that contributes to soil weathering, due to the transformation of illite-vermiculite, releasing K. The depletion of nutrients from the soil biomass was in the order: P>S>N>K>Mg>Ca. Phosphorus and S were the most limiting in scenario A due to their low stock in the soil. In scenario B, the number of forest rotations was limited by N, K, and S. Scenario C showed the greatest reduction in productivity, allowing only two rotations before P limitation. It is therefore apparent that there may be a difference of up to 30 years in the capacity of the soil to support a scenario such as A, with a low nutrient removal, compared to scenario C, with a high nutrient removal. Hence, the effect of different harvesting intensities on nutrient availability may jeopardize the sustainability of P. taeda in the short-term.
Resumo:
Introduction: The latest data on prevalence of overweight (OW) and obesity (OB) in the general Swiss resident population rely on the Swiss Health Survey (SHS), a telephonic interview performed in 2007. However, body mass index (BMI) is underestimated when self-reported, leading to a misclassification of up to 60% of obese subjects. The last survey with measured BMI performed in the 3 linguistic regions of Switzerland dates back to 1977. We explored the regional prevalences of OW and OB by measured BMI in the general Swiss resident population. Methods: Cross-sectional population-based survey in the 3 linguistic regions of Switzerland in 2010-2011. Data on 1471 participants aged 15-95 years (712 men, 759 women) were available for the analysis. BMI was calculated from measured height and weight and categorized into 3 groups according to WHO classification: lean (<25 kg/m2), overweight (25-30 kg/m2) and obese (>= 30 kg/m2). Data on medication, smoking, education, physical activity and dietary habitudes were collected using a questionnaire. Results: The overall prevalence of OW and OB was 32.1% and 13.9%, respectively. OB prevalence was similar across the 3 linguistic regions (13.5% in German-, 15.6% in French- and 12.0% in Italian-speaking Switzerland, p = 0.40), unlike OW prevalence, which significantly differed in unadjusted analyses (35.4%, 29.1% and 25.4%, respectively, p = 0.005). In analyses including age, sex, smoking, physical activity and education as covariates, living in the Italian-speaking region was associated neither with BMI (linear regression) nor with OW or OB (logistic regressions) . Age (beta coefficient [SE]: 0.064[0.006] kg/m2 per year, p <0.001) and sex (-1.76 [0.23] kg/m2 in women, p <0.001) were significantly associated with BMI. Conclusions: Overweight and obesity affect nearly half of the Swiss population aged >15 years. We observed no significant differences across regions once we accounted for age, sex, education and lifestyle. Public health interventions addressing modifiable behavioral factors to reduce overweight and obesity in Switzerland can be expected to have substantial benefits.
Resumo:
OBJECTIVES: To obtain information about the prevalence of, reasons for, and adequacy of HIV testing in the general population in Switzerland in 1992. DESIGN: Telephone survey (n = 2800). RESULTS: Some 47% of the sample underwent one HIV test performed through blood donation (24%), voluntary testing (17%) or both (6%). Of the sample, 46% considered themselves well or very well informed about the HIV test. Patients reported unsystematic pre-test screening by doctors for the main HIV risks. People having been in situations of potential exposure to risk were more likely to have had the test than others. Overall, 85% of those HIV-tested had a relevant, generally risk-related reason for having it performed. CONCLUSIONS: HIV testing is widespread in Switzerland. Testing is mostly performed for relevant reasons. Pre-test counselling is poor and an opportunity for prevention is thus lost.
Resumo:
Question: Outdoor occupational exposure could be associated with important cumulative and intense exposure to ultraviolet (UV) solar radiation. Such exposure would increase risk of skin cancer. However, little information exists on jobs associated with intense UV exposure. The objective of this study was to characterise occupational UV exposure in a representative sample in France. Methods: A population-based survey was conducted in May-June 2012 through computer-assisted telephonic interviews in population 25 to 69 years of age. Individual UV irradiation was computed with declared time and place of residence matched to UV records from satellite measurement (Eurosun project). We analysed factors influencing exposure to UV (annual average and seasonal peak). Results: A total of 1442 individuals declared having an occupational exposure to UV which represents 18% of population aged 25 to 69 years. Outdoor workers were more frequently men (58%), aged 40-54 (43%), with a phototype III or IV (69%). Occupations associated with highest UV exposure were: construction workers (annual daily average 62.8 Joules/m2), gardeners (62.6), farmers (52.8), culture/art/social sciences workers (52.0) and transport workers/mail carriers (49.5). The maximum of UVA exposure was found for occupation with a strong seasonality of exposure: culture, art or social sciences works (98.1 Joules/m2), construction works (97.2), gardening (96.7) and farming (95.0). Significant factors associated with high occupational UV exposure were gender (men vs. women: 53.6 vs. 42.6), phototype (IV vs. I: 51.9 vs. 45.5) and taking lunch outdoors (always vs. never: 59.8 vs. 48.6). Conclusion: Our study showed that some occupations were associated with particularly intense UV exposure such as farmers, gardeners, construction workers. Other unexpected occupations were also associated with high UV exposure such as transport workers, mail carriers and culture/art/social sciences workers.
Resumo:
OBJECTIVE: To examine the compliance to medication among newly diagnosed hypertensive patients screened from the general population of the Seychelles, a rapidly developing country. METHODS: Among the 1067 participants to a population-based survey for cardiovascular risk factors, hypertension was discovered in 50 (previously unaware of having hypertension and having blood pressure > or = 160/95 mmHg over 3 visits). These 50 patients were placed on a daily one-pill regimen of medication (bendrofluazide, atenolol, or a combination of hydrochlorothiazide and atenolol) and compliance to the regimen was assessed over 12 months using electronic pill containers. Satisfactory compliance was defined as taking the medication on 6 or 7 days a week on average (which corresponds to a mean compliance level of > or = 86%). FINDINGS: In the first month, fewer than half (46%) of the new hypertension patients achieved satisfactory compliance, and only about one-quarter (26%) achieved this level by the twelfth month. Compliance was better among the 23 participants who regularly attended medical follow-up, with nearly three-quarters of these patients (74%) achieving satisfactory compliance during the first month and over one-half (55%) by the twelfth month. There was a direct association between mean 12-month compliance level and having a highly skilled occupation; having good health awareness; and regularly attending medical appointments. In contrast, there was an inverse relationship between mean compliance level and heavy drinking. CONCLUSION: The low proportion of people selected from the general population who were capable of sustaining satisfactory compliance to antihypertension medication may correspond to the maximum effectiveness of medication interventions based on a screening and treatment strategy in the general population. The results stress the need for both high-risk and population approaches to improve hypertension control.
Resumo:
BACKGROUND: Among the many definitions of frailty, the frailty phenotype defined by Fried et al. is one of few constructs that has been repeatedly validated: first in the Cardiovascular Health Study (CHS) and subsequently in other large cohorts in the North America. In Europe, the Survey of Health, Aging and Retirement in Europe (SHARE) is a gold mine of individual, economic and health information that can provide insight into better understanding of frailty across diverse population settings. A recent adaptation of the original five CHS-frailty criteria was proposed to make use of SHARE data and measure frailty in the European population. To test the validity of the SHARE operationalized frailty phenotype, this study aims to evaluate its prospective association with adverse health outcomes. METHODS: Data are from 11,015 community-dwelling men and women aged 60+ participating in wave 1 and 2 of the Survey of Health, Aging and Retirement in Europe, a population-based survey. Multivariate logistic regression analyses were used to assess the 2-year follow up effect of SHARE-operationalized frailty phenotype on the incidence of disability (disability-free at baseline) and on worsening disability and morbidity, adjusting for age, sex, income and baseline morbidity and disability. RESULTS: At 2-year follow up, frail individuals were at increased risk for: developing mobility (OR 3.07, 95% CI, 1.02-9.36), IADL (OR 5.52, 95% CI, 3.76-8.10) and BADL (OR 5.13, 95% CI, 3.53-7.44) disability; worsening mobility (OR 2.94, 95% CI, 2.19- 3.93) IADL (OR 4.43, 95% CI, 3.19-6.15) and BADL disability (OR 4.53, 95% CI, 3.14-6.54); and worsening morbidity (OR 1.77, 95% CI, 1.35-2.32). These associations were significant even among the prefrail, but with a lower magnitude of effect. CONCLUSIONS: The SHARE-operationalized frailty phenotype is significantly associated with all tested health outcomes independent of baseline morbidity and disability in community-dwelling men and women aged 60 and older living in Europe. The robustness of results validate the use of this phenotype in the SHARE survey for future research on frailty in Europe.
Resumo:
Question: Outdoor workers can be exposed to intense ultraviolet (UV) solar radiation likely to results to sunburns. As sunburn is an important risk factor for skin cancer, in particular melanoma, we investigated the causes of occupational sunburns (OS) in French outdoor workers. Methods: A population-based survey was conducted in May-June 2012 through computer-assisted telephonic interviews in population 25 to 69 years of age. History of sunburn from occupational exposure within the year preceding interview was collected. We analysed the risk of OS in multivariate logistic regression. Results: Out of 1442 individuals who declared having an occupational exposure to solar UV radiation, 403 (27.9%) reported a sunburn from occupational exposure in the year preceding the interview. Sunburns were more frequent in women (30% vs. 26.4% in men although not significant p = 0.14), in younger workers (p = 0.0099), in sensitive phototype (40% in phototype I/II vs. 23% in phototype III/IV, p < 0.001) and in workers taking lunch outdoor (p = 0.0355). Some occupations were more associated with OS (more than 30%): health occupations, managing, research/engineering, construction workers and culture/art/social sciences workers. In multivariate analysis, risk factors for OS are phototype (I vs. IV, OR = 4.30 95% CI [2.65-6.98]), sunburn during leisure time (OR = 3.46 95% CI [2.62-4.59]), seasonality of exposure (seasonal vs. constant exposure OR = 1.36 95% CI [1.02-1.81] and annual UVA exposure (OR for 10J/m² daily average increment 1.08 95% CI [1.02-1.14]). In multivariate analysis the type of occupation was not associated with increased OS. Conclusion: Sunburns from occupation was also observed in non sensitive population, phototype IV, which shows that outdoor workers are potentially exposed to intense UV radiations. This study suggests that prevention should target UV sensitive outdoor workers as well as those cumulating intense UV exposure.
Resumo:
The objective of this study was to characterize weapon-carrying adolescents and to assess whether weapon carriers differ from weapon users. Data were drawn from a cross-sectional school-based survey of 7548 adolescents aged 16-20 years in Switzerland. Youths carrying a weapon were compared with those who do not. Subsequently, weapon carriers were divided into those who had used it in a fight and those who had not. Individual, family, school and social factors were analyzed using bivariate and stepwise multivariate analysis. For both genders, delinquent behavior and being victim of physical violence were associated with weapon carrying. For males, quarreling while intoxicated, being an apprentice, being sensation seekers, having a tattoo, having a poor relationship with parents and practicing unsafe sex were also related to weapon carrying. Compared with weapon carriers, female weapon users were more likely to be regular smokers. Male weapon users were foreign born, urban and apprentices; had poor school connectedness; practiced unsafe sex and quarreled while intoxicated. Carrying a weapon is a relatively frequent behavior among youths in Switzerland and a sizeable proportion of weapon carriers have used it in a fight. Weapon carrying should be part of the clinical assessment and preventive counseling of adolescents. Preventive programs specific for at-risk youth groups need to be developed.
Resumo:
Introduction. Adherence to medication for asymptomatic disease is often low. We assessed factors associated with good adherence to medication for high blood pressure (HBP) in a country of the African region. Methods. A population-based survey of adults aged 25-64 years (N=1240 and participation rate=73%). Information was available in knowledge attitude and practice, SES and other variables. One question assessed adherence. Good adherence to treatment was defined as answering "I forget very rarely" vs "I forget on 1-2 days in a week" or "I forget on 3 or more days in a week". Results. In a univariate model adherence was strongly associated with belief that hypertension is a long-term disease (OR 2.6, p<0.001) and was negatively associated with concomitant use of traditional medicine (OR 0.36, p<0.005). The following variables tended to be associated with good adherence for HBP treatment: age, SES, BMI, belief that HBP is not symptomatic, going to government's clinics, medium stress level, controlled hypertension, taking statins. The following variables were not associated with good adherence for HBP treatment: education, higher BP, knowing people who had a stroke/MI, suffering from another chronic condition. In a multivariate model, pseudo R2 was 0.14. Conclusion. We built a multidimensional model including a wide range of variable. This model only predicted 14% of adherence variability. Variables associated with good adherence were demographics or related to knowledge attitude and practice. The latter one is modifiable by different type of interventions.
Resumo:
BACKGROUND: Frailty is an indicator of health status in old age. Its frequency has been described mainly for North America; comparable data from other countries are lacking. Here we report on the prevalence of frailty in 10 European countries included in a population-based survey. METHODS: Cross-sectional analysis of 18,227 randomly selected community-dwelling individuals 50 years of age and older, enrolled in the Survey of Health, Aging and Retirement in Europe (SHARE) in 2004. Complete data for assessing a frailty phenotype (exhaustion, shrinking, weakness, slowness, and low physical activity) were available for 16,584 participants. Prevalences of frailty and prefrailty were estimated for individuals 50-64 years and 65 years of age and older from each country. The latter group was analyzed further after excluding disabled individuals. We estimated country effects in this subset using multivariate logistic regression models, controlling first for age, gender, and then demographics and education. RESULTS: The proportion of frailty (three to five criteria) or prefrailty (one to two criteria) was higher in southern than in northern Europe. International differences in the prevalences of frailty and prefrailty for 65 years and older group persisted after excluding the disabled. Demographic characteristics did not account for international differences; however, education was associated with frailty. Controlling for education, age and gender diminished the effects of residing in Italy and Spain. CONCLUSIONS: A higher prevalence of frailty in southern countries is consistent with previous findings of a north-south gradient for other health indicators in SHARE. Our data suggest that socioeconomic factors like education contribute to these differences in frailty and prefrailty.
Resumo:
Background: We examined one's own body image perception and its association with reported weight-related behavior among adolescents of a rapidly developing country in the African region. Methods: We conducted a school-based survey of 1432 students aged 11-17 years in the Seychelles. Weight and height were measured, and thinness, normal weight and overweight were assessed along standard criteria. A self-administered and anonymous questionnaire was administered. Perception of body image was assessed using both a closed-ended question (CEQ) and the Stunkard's pictorial silhouettes (SPS). Finally, a question assessed voluntary attempts to change weight. Results: Overall, 14.1% of the students were thin, 63.9% were normal-weight, and 22.0% were overweight or obese. There was fair agreement between actual weight status and self-perceived body image based on either CEQ or SPS. However, a substantial proportion of the overweight students did not consider themselves as overweight (SPS: 24%, CEQ: 34%) and, inversely, a substantial proportion of the normal-weight students considered themselves as too thin (SPS: 29%, CEQ: 15%). Among the overweight students, an adequate attempt to lose weight was reported more often by boys and girls who perceived themselves as overweight vs. not overweight (72-88% vs. 40-71%, p <0.05 for most comparisons). Among the normal-weight students, an inadequate attempt to gain weight was reported more often by boys and girls who perceived themselves as thin vs. not thin (27-68% vs. 11-19%, p <0.05). Girls had leaner own body ideals than boys. Conclusions: We found that substantial proportions of overweight students did not perceive themselves as overweight and/or did not want to lose weight and, inversely, that many normalweight students perceived themselves as too thin and/or wanted to gain weight: this points to forces that can drive the upwards overweight trends. Appropriate perception of one's weight was associated with adequate weight-control behavior, although not strongly, emphasizing that appropriate weight perception is only one of several factors driving adequate weight-related behavior. These findings emphasize the need to address appropriate perception of one's own weight and adequate weight-related behavior in adolescents for both individual and community weight-related interventions.
Resumo:
BACKGROUND: Current guidelines recommend treating patients according to their absolute cardiovascular disease (CVD) risk. We examined perception of CVD risk among adults and how it can be compared with actual CVD risk. METHODS: The perception of CVD risk was assessed by two questions asking about participants' 'risk to get a heart attack or a stroke over the next 10 years' using semiquantitative and quantitative answers in a population-based survey of 816 individuals aged 40-64 years in the Seychelles (African region). Actual CVD risk was calculated using a standard risk prediction score and 24% of adults aged 40-64 years had elevated risk. RESULTS: Only 59% of individuals could give an estimate of perceived CVD risk based on the semiquantitative question and 31% based on the quantitative question. Reporting a perceived CVD risk was strongly associated with high socio-economic status (SES; odds ratio = 9). Among individuals who reported a perceived CVD risk, 48% overestimated their perceived risk versus their actual risk. Reporting a high perceived CVD risk was associated with treatment for CVD risk factors, older age, low SES, and overweight. Reporting a low perceived CVD risk was associated with male sex, younger age, education, normal BMI, and leisure time exercise. CONCLUSION: Only half of the individuals could provide an estimate of their perceived CVD risk, and this perception was strongly associated with SES. Individuals under treatment perceived higher CVD risk than nontreated individuals. Further studies should determine how risk-related information can be better conveyed to individuals as a means to improve adherence to healthy lifestyles and/or treatment.
Resumo:
Tämän tutkimuksen tavoitteena oli selvittää, vaikuttaako kansainvälisen opiskelijan kulttuuritausta opiskelijan odotetun ja koetun yliopistoimagon muodostumiseen. Jotta kulttuurin vaikutuksia yliopistoimagoon voitiin tutkia, tutkimuksessa tunnistettiin yliopistoimagon muodostumiseen oleellisesti vaikuttavat tekijät. Kulttuurin roolia organisaation imagon muodostumisessa ei ole tutkittu aiemmissa tieteellisissä julkaisuissa. Näin ollen tämän tutkimuksen voidaan katsoa edistäneen nykyistä imagotutkimusta. Tutkimuksen kohdeyliopistona oli Lappeenrannan teknillinen yliopisto (LTY). Tutkimuksen empiirinen osa toteutettiin kvantitatiivisena Internet - pohjaisena kyselytutkimuksena tilastollisen analyysin menetelmin. Otos (N=179) koostui kaikista Lappeenrannan teknillisessä yliopistossa lukuvuonna 2005-2006 opiskelleista kansainvälisistä opiskelijoista. Kyselyyn vastasi 68,7 % opiskelijoista. Johtopäätöksenä voidaan todeta, että kulttuurilla ei ole merkittävää vaikutusta yliopistoimagon muodostumiseen. Tutkimuksessa saatiin selville, että yliopiston Internet-sivujen laatu vaikuttaa positiivisesti odotetun yliopistoimagon muodostumiseen, kun taas koettuun yliopistoimagoon vaikuttavat positiivisesti odotettu yliopistoimago, pedagoginen laatu sekä opetusympäristö. Markkinoinnin näkökulmasta tulokset voidaan vetää yhteen toteamalla, että yliopistojen ei tarvitsisi räätälöidä tutkimuksessa tunnistettuja imagoon vaikuttavia tekijöitä eri kulttuureistatulevia opiskelijoita varten.