Thomas Volken

Second-stage non-response in the Swiss health survey: determinants and bias in outcomes.

BackgroundUnit non-response occurs in sample surveys when a target subject does not respond to a survey. Potential implications are decreased power, increased standard error, and non-response bias. The objective of this study was to assess the factors associated with participation in a written survey (MSHS) of subjects who had previously participated in the Swiss Health Survey (SHS) and to evaluate to what extent non-participation could impact the estimation of various MSHS health outcomes.MethodsMultivariate logistic regression was used to assess the factors associated with MSHS participation (n=14,393) by eligible SHS participants (n=17,931). Crude participation rates and the adjusted odds ratios of participation (OR) were reported. In order to report potential bias in MSHS outcomes, the average age-standardized and sex-specific outcome values in non-participants were predicted based on several different linear regression models which had been previously fitted on MSHS participants.ResultsAdjusting for all other variables, women (OR=1.63) as compared with men, subjects with a secondary (OR=1.48) or tertiary education (OR=1.76) as compared with those with primary education, white-collar workers (high level non-manual workers OR=1.29, medium and low level non-manual workers OR=1.26 and OR=1.25 respectively) as compared with unskilled manual workers, Swiss nationals (OR=1.60) as compared to non-Swiss, and subjects with very good or good self-rated health (OR=1.35) were more likely to participate in the MSHS. People who work full-time were less likely to participate than those without paid work (OR=0.76). There were no statistically significant differences in the likelihood of participation between rural and urban areas, different geographic regions of Switzerland and household income quartiles.Except for myocardial infarction, all age-standardized and sex-specific average outcomes (influenza vaccination, arthrosis, osteoporosis, high blood pressure, depression, mastery, and sense of coherence) were significantly different between MSHS non-participants and participants.ConclusionsSubjects who participated in the MSHS had a higher socio-economic status, reported a better subjective health, and were more likely to be Swiss nationals. Small to moderate bias was found for most age-adjusted and sex-specific average outcomes. Consequently, these MSHS outcomes should be used and interpreted with care.

Reliability of quantifying the spatial distribution of fatty infiltration in lumbar paravertebral muscles using a new segmentation method for T1-weighted MRI

BackgroundTo our knowledge, there are no methods allowing for quantification of the spatial distribution of lumbar paravertebral muscle fatty infiltration (FI) in the transverse plane. There is an increasing emphasis on muscle tissues as modifiable factors in lumbar spine health. Population datasets based on conventional T1-weighted (T1-W) magnetic resonance imaging (MRI) represent a valuable resource for examining all spinal tissues, and methods with reliability are needed. The aim of our study was to determine the reliability of a novel method quantifying lumbar paravertebral muscle fat content based on conventional T1-W MRI.MethodsAxial 3-Tesla T1W MRIs from ten adult subjects (3W, 7M; mean age 52.8 ± SD 7.2 years) were randomly selected from the large prospective cross-sectional Hong Kong Population-based Disc Degeneration Cohort study examining lumbar spine degeneration. The selected sample included subjects with mixed imaging-determined disc degeneration and low back pain history. Two raters with MRI lumbar paravertebral muscle analysis experience (R1 > 250 h and R2 > 1000 h) repeat-measured the image-set a week apart. Multifidus and erector spinae (spinalis, longissimus and iliocostalis) were manually outlined together on a single-slice from the inferior vertebral end-plates of L1 to L5 using a semi-automated, quartile-defining (Q1-4 (medial to lateral) and Qmean) MatLab-based programme. Bland-Altman plots and intra-class correlation coefficients (ICC) with 95 % confidence intervals (CI) describe intra- and inter-rater reliability according to lumbar level, quartile, and side, and combined level and quartile.ResultsThere was good intra- (ICC = 0.88; CI: 0.87–0.90) and inter-rater agreement (ICC = 0.82; CI: 0.80–0.84). Intra-rater values for Qmean (ICC; CI) were higher at L5 (0.89; 0.79–0.94) than L1 (0.61; 0.37–0.78). Higher intra-rater values for L1-5 were shown at Q1 (0.93; 0.91–0.95) than Q3 (0.83; 0.78–0.87) or Q4 (0.81; 0.76–0.85), and on the right (0.91; 0.90–0.93) than left (0.85; 0.83–0.88). Similar observations were made for inter-rater values in terms of lumbar level and quartile, with no differences between sides shown.ConclusionsIn our study of ten cases we demonstrate a reliable method to quantify the spatial distribution of fat content in lumbar paravertebral muscles based on T1W MRI. Understanding the geography of fat content in these muscles may offer additional insight in determining and improving spinal health. The clinical relevance and application of this method require testing across various populations to build on the early feasibility established in this study.

Individual Characteristics Associated with Blood Donation: A Cross-National Comparison of the German and Swiss Population between 1994 and 2010

Objective: The aim of this study is to compare individual characteristics associated with blood donation in the German and Swiss population between 1994 and 2010. Methods: Population-based survey data from the Eurobarometer 1994 and 2009, the Swiss Health Survey 1997, and the Swiss Blood Donation Survey 2010 were used to compare age-adjusted percentages of German and Swiss adults ever having donated blood (n = 8,746). A multivariate logistic regression was applied to the pooled data to estimate odds ratios (OR). Results: Donor rates between 1994 and 2010 increased by 8.6% in Germany (p = 0.0045) and remained stable in Switzerland. The likelihood to report donating increased with age. Gender differences (OR = 2.85; p = 0.0000) and differences between education levels were more pronounced in Switzerland as compared to Germany (OR = 2.56; p = 0.0000 and OR = 2.73; p = 0.0010). Furthermore education differences were more marked in men in both countries (OR = 1.99; p = 0.0000 and OR = 1.68; p = 0.0140). Conclusion: The blood establishments should intensify their efforts to motivate women and lower educated people to give blood. Our data suggest that population-based surveys could be a helpful tool to describe donor rates in different countries and to guide future recruitment strategies.

Fruit and vegetable consumption among migrants in Switzerland

OBJECTIVE To assess the relative risk of low daily fruit and vegetable consumption for six large migrant groups in Switzerland. DESIGN Cross-sectional health survey carried out 2007 (Swiss Health Survey) and 2010 (Swiss Migrant Health Survey) in Switzerland. Multinomial logistic regression models were used to estimate relative risk rates (RRR) of migrants relative to Swiss nationals. SETTING Data obtained from representative samples of Swiss and foreign nationals living in Switzerland. SUBJECTS A random sample (n =14637) of the Portuguese, German, Italian, Turkish, Serbian, Kosovan and Swiss permanent resident adult population (17-64 years old) was interviewed. RESULTS The proportion of participants who adhered to the recommended fruit and vegetable consumption was below one-third in all study populations. Compared with Swiss nationals, the relative risk of low daily fruit and vegetable intake relative to recommended intake was higher in Turkish nationals (RRR = 2.92, 95 % CI 1.91, 4.48; P = 0.0000) and Kosovan nationals (RRR = 4.76, 95 % CI 3.01, 7.55; P = 0.0000). The respective relative risks of Portuguese, Serbian, German and Italian nationals were not significantly different from the Swiss reference group. CONCLUSIONS Initiatives for the promotion of fruit and vegetable consumption should continue to address the population at large. At the same time, programmes that are tailored to the specific needs of migrants from Turkey and Kosovo should be considered.

Blood donor to inactive donor transition in the Basel region between 1996 and 2011: a retrospective cohort study

For the prevention of blood shortages, it is essential for blood banks to design and implement donor recruitment and donor retention strategies that take into account the determinants of donor return.

Need for weight management in Switzerland: findings from National Blood Pressure Week 2009

BackgroundThe Swiss Health Survey (SHS) provides the only source of data for monitoring overweight and obesity in the general population in Switzerland. However, this survey reports body mass index (BMI) based on self-reported height and weight, and is therefore subject to measurement errors. Moreover, it is not possible to differentiate between overall and abdominal overweight. In this study, we aimed to gain a better understanding of the need for weight management in the general population of Switzerland by exploring and comparing prevalence rates of BMI and waist circumference (WC) based on physical measurements by trained observers, based on data from the 2009 National Blood Pressure Week (NBPW).MethodsSample selection was based on a one-stage cluster design. A total of 385 pharmacies representing 3,600 subjects were randomly selected from pharmacies participating in NBPW. BMI measures based on physical weight and height (NBPW) were compared with self-reported BMI measures from the SHS. BMI and WC measurements from NBPW were then used to produce population estimates of overweight and obesity.ResultsBMI-based overall prevalence of overweight and obesity was 43.6%, which was 4.7% higher than the value based on the respective SHS data. Overweight and obesity were more common in men (54.3%) than in women (33.5%). However, the overall prevalence of increased WC in the general population was estimated to be 64.4%, with more women (68.4%) than men (60.1%) exhibiting a WC above the threshold. The prevalence of subjects requiring weight management in the Swiss population remained high, even after adjusting WC for false positive and negative cases.ConclusionsFirstly, it may be more appropriate for health promotion programs to address the wider group identified by WC, which includes subjects who need to reduce their weight, or gain no further weight. Secondly, the gender differences are reversed depending on the use of WC or BMI to identify subjects suitable for health promotion programs; more women than men are identified by WC, and more men than women using BMI. These differences should be accounted for in gender-specific health promotion programs.

Giving blood and enrolling on the stem cell donor registry: ranking of obstacles and motives in Switzerland.

Background: To obtain a better understanding of factors affecting blood and blood stem cell donation behavior in Switzerland, a series of studies has been performed. In the recent study of this series, which is described here, motivators and barriers in the field of blood and blood stem cell donation were identified. Methods: Web-based survey data from a non-random sample of the Swiss population 2012/2013 (n = 3,153) were used to describe and compare the ranking of motives and obstacles to donate blood and to enroll on the Swiss blood stem cell registry. Wilcoxon rank-sum test and Spearmans rank correlations were used to assess differences and associations between ranks and groups. Results: The prospect of saving lives and solidarity were the top two motives to donate blood or to enroll on the blood stem cell registry. The top two obstacles to enroll on the blood stem cell registry were lack of general information on blood stem cell donation and on its risks, whereas the top two obstacles to donate blood were the lack of information where and when to donate and deferral of or exclusion from blood donation. Conclusion: Classical altruistic motives are top drivers for giving blood as well as registering for blood stem cell donation. Recruitment campaigns should focus on these motivators. Similarities in motivational factors as well as in obstacles regarding blood and blood stem cell donation can be found.

Iron deficiency and thrombocytosis

According to many textbooks, iron deficiency (ID) is associated with reactive thrombocytosis. In this study, we aimed to investigate the correlation between serum ferritin levels and platelet counts in a large cohort of healthy blood donors. We included all whole blood and apheresis donors aged 18 years or older with at least one ferritin measurement and one platelet count performed at the same visit between 1996 and 2014. A total of 130 345 blood counts and ferritin measurements obtained from 22 046 healthy donors were analysed. Overall, no correlation between serum ferritin and platelet count was observed (r = −0.03, ρ = 0.04 for males, and r = 0.01, ρ = −0.02 for females, respectively). Associations remained clinically negligible after adjusting for age, time since previous blood donation, number of donations and restricting the analysis to ferritin deciles. In this large, retrospective single‐centre study, correlations between low ferritin and platelet count in a large and homogeneous cohort of healthy donors were negligible. Further studies in patients with more severe anaemia and patients with inflammation are warranted.

Blood Group Distribution in Switzerland - a Historical Comparison.

Background: Ethnicities differ in prevalence of blood groups and antigens. Substantial donor-recipient mismatch within mixed-ethnic societies may render certain recipients at higher risk for alloimmunization. Data regarding antigen distribution within Switzerland by ethnicity is limited. We examined immigration patterns against the distribution of ABO blood groups using large cross-sectional Swiss samples spanning 70 years. Methods: Historical ABO blood group distribution data (1940-1945) from Swiss army personnel (n = 275,664) were sourced from the literature. Recent blood group phenotypes of 122,925 individuals who presented themselves at army recruitment centers (2004-2015) were obtained, alongside a validation sample of 175,202 patients from a university hospital. Two-sample tests with z-statistics assessing blood groups between samples were used. Results: The respective proportions of A (47.2% and 45.2%), B (8.4% and 9.8%), and AB (3.0 and 4.1) in the historical and recent army samples were significantly different (p < 0.001), while group O was not. Conclusion: ABO blood groups in Switzerland have remained stable despite substantial immigration with a changing foreign-national profile. Further research is needed to improve the understanding of antigen differences in newly introduced ethnic groups. Blood product requirements and public health initiatives aimed at recruiting blood donors would benefit from this information.

European Academy of Nursing Science and the Swedish Society of Nursing Summer Conference 2017: The Future Direction of European Nursing and Nursing Research

Osteoporosis is highly prevalent worldwide and is associated with increased risk of low trauma fracture (LTF) [1], increased morbidity and mortality [2]. Major advances in diagnosis, management and BMC Nursing 2017, 16(Suppl 1):32 Page 3 of 11 prevention of secondary fractures have occurred [3] but implications for acute nursing care are less well documented. This project investigated practitioners’ experiences of caring for people with osteoporosis, knowledge of the disease, explored implications for moving and handling, reported patients’ care experiences, and developed education for frontline staff.We welcome all high quality abstracts related to the following three conference themes: Methodological innovations moving beyond the established; Researching nursing interventions moving beyond the “uniqueness” of nursing; Humanitus – returning to the essential principles of clinical nursing care. Online submission opens 16th of August, 2016 on www.swenurse.se Submission deadline is 18th of November, 2016 Call for Abstracts – The 2017 European Conference in Nursing and Nursing Research Fo to : W er n er N ys tr an d