Inferring R0 in emerging epidemics: the effect of common population structure is small

When controlling an emerging outbreak of an infectious disease, it is essential to know the key epidemiological parameters, such as the basic reproduction number R0 and the control effort required to prevent a large outbreak. These parameters are estimated from the observed incidence of new cases and information about the infectious contact structures of the population in which the disease spreads. However, the relevant infectious contact structures for new, emerging infections are often unknown or hard to obtain. Here, we show that, for many common true underlying heterogeneous contact structures, the simplification to neglect such structures and instead assume that all contacts are made homogeneously in the whole population results in conservative estimates for R0 and the required control effort. This means that robust control policies can be planned during the early stages of an outbreak, using such conservative estimates of the required control effort

Perinatal characteristics and risk of polio among Swedish twins

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90577/1/j.1365-3016.2012.01268.x.pd

Vulnerable Users’ Perceptions of Transport Technologies

As the global population continues to grow, age and urbanize, it is vital to provide accessible transport so that neither ageing nor disability constitute barriers to social inclusion. While technology can enhance urban access, there is a need to study the ways by which transport technologies - real-time information, pedestrian navigation, surveillance, and road pricing - could be more effectively adopted by users. The reason for this is that some people, and particularly vulnerable populations, are still likely to reluctantly use (or even avoid using) technologies perceived as 'unknown' and 'complicated'. Based on evidence from British and Swedish case studies on older people's perceptions of the aforementioned transport technologies, as well as on a Swedish case study of visually impaired people's perceptions, this article makes the case that technology is only one tool in a complex socio-technical system, and one which brings challenges. The authors also suggest that although vulnerable populations are not homogeneous when expressing attitudes towards transport technologies, their assessment criteria tend to be 'pro-social' as they usually consider that the societal benefits outweigh the personal benefits. Emphasising aspects linked to the technologies' pro-social potential or relevance to the individual user could increase acceptance

Experiences of dementia in a foreign country: qualitative content analysis of interviews with people with dementia

Background: Dementia is a worldwide health concern of epidemic proportions. Research in the field of subjective experience of dementia suffers from a lack of diversity of their participants including immigrants. Different portraits of life with dementia could help us understand how people with dementia conceptualise their experiences of dementia and how they live. Our study aimed to explore the subjective experiences of living with dementia among Iranian immigrants in Sweden. Methods: Qualitative content analysis of interviews with fifteen people with dementia from Iranian immigrant backgrounds were conducted (8 females and 7 males). Results: Three themes and seven associated sub-themes were revealed. The themes included: Being a person with dementia means living with forgetfulness (personal sphere), living with forgetfulness in the private sphere means feeling incompetent but still loved, living with forgetfulness in the public sphere means feeling confident and secure but also isolated. Conclusions: Living with dementia for the participants meant living with forgetfulness. They experienced feeling incompetent but still loved within their families and feeling confident and secure but also isolated in the society. Educating people with dementia and their families about the course and process of dementia may help them understand the changes better and adjust their expectations. Our study can provide a basis for healthcare workers to understand the experiences of living with dementia from this specific perspective

Trajectory of vitamin D status during pregnancy in relation to neonatal birth size and fetal survival: a prospective cohort study

Background: We investigated the associations between vitamin D status in early and late pregnancy with neonatal small for gestational age (SGA), low birth weight (LBW) and preterm delivery. Furthermore, associations between vitamin D status and pregnancy loss were studied. Methods: Serum 25-hydroxyvitamin D (25OHD) was sampled in gestational week ≤ 16 (trimester 1 (T1), N = 2046) and > 31 (trimester 3 (T3), N = 1816) and analysed using liquid chromatography tandem mass spectrometry. Pregnant women were recruited at antenatal clinics in south-west Sweden at latitude 57–58°N. Gestational and neonatal data were retrieved from medical records. Multiple gestations and terminated pregnancies were excluded from the analyses. SGA was defined as weight and/or length at birth < 2 SD of the population mean and LBW as < 2500 g. Preterm delivery was defined as delivery < 37 + 0 gestational weeks and pregnancy loss as spontaneous abortion or intrauterine fetal death. Associations between neonatal outcomes and 25OHD at T1, T3 and change in 25OHD (T3-T1) were studied using logistic regression. Results: T1 25OHD was negatively associated with pregnancy loss and 1 nmol/L increase in 25OHD was associated with 1% lower odds of pregnancy loss (OR 0.99, p = 0.046). T3 25OHD ≥ 100 nmol/L (equal to 40 ng/ml) was associated with lower odds of SGA (OR 0.3, p = 0.031) and LBW (OR 0.2, p = 0.046), compared to vitamin D deficiency (25OHD < 30 nmol/L, or 12 ng/ml). Women with a ≥ 30 nmol/L increment in 25OHD from T1 to T3 had the lowest odds of SGA, LBW and preterm delivery. Conclusions: Vitamin D deficiency in late pregnancy was associated with higher odds of SGA and LBW. Lower 25OHD in early pregnancy was only associated with pregnancy loss. Vitamin D status trajectory from early to late pregnancy was inversely associated with SGA, LBW and preterm delivery with the lowest odds among women with the highest increment in 25OHD. Thus, both higher vitamin D status in late pregnancy and gestational vitamin D status trajectory can be suspected to play a role in healthy pregnancy

Colorectal Cancer Prognosis Following Obesity Surgery in a Population-Based Cohort Study

Background: Obesity surgery involves mechanical and physiological changes of the gastrointestinal tract that might promote colorectal cancer progression. Thus, we hypothesised that obesity surgery is associated with poorer prognosis in patients with colorectal cancer. Methods: This nationwide population-based cohort study included all patients with an obesity diagnosis who subsequently developed colorectal cancer in Sweden from 1980 to 2012. The exposure was obesity surgery, and the main and secondary outcomes were disease-specific mortality and all-cause mortality, respectively. Cox proportional hazard survival models were used to calculate hazard ratios (HRs) with 95% confidence intervals (CIs), adjusted for sex, age, calendar year and education level. Results: The exposed and unexposed cohort included 131 obesity surgery and 1332 non-obesity surgery patients with colorectal cancer. There was a statistically significant increased rate of colorectal cancer deaths following obesity surgery (disease-specific HR 1.50, 95% CI 1.00–2.19). When analysed separately, the mortality rate was more than threefold increased in rectal cancer patients with prior obesity surgery (disease-specific HR 3.70, 95% CI 2.00–6.90), while no increased mortality rate was found in colon cancer patients (disease-specific HR 1.10, 85% CI 0.67–1.70). Conclusion: This population-based study among obese individuals found a poorer prognosis in colorectal cancer following obesity surgery, which was primarily driven by the higher mortality rate in rectal cancer

Obesity prevalence in a cohort of women in early pregnancy from a neighbourhood perspective

<p>Abstract</p> <p>Background</p> <p>The evidence of an association between neighbourhood deprivation and overweight is established for different populations. However no previous studies on neighbourhood variations in obesity in pregnant women were found. In this study we aimed to determine whether obesity during early pregnancy varied by neighbourhood economic status.</p> <p>Methods</p> <p>A register based study on 94,323 primiparous pregnant women in 586 Swedish neighbourhoods during the years 19922001. Multilevel technique was used to regress obesity prevalence on socioeconomic individual-level variables and the neighbourhood economic status. Five hundred and eighty-six neighbourhoods in the three major cities of Sweden, Stockholm, Göteborg and Malmö, during 19922001, were included. The majority of neighbourhoods had a population of 4 00010 000 inhabitants.</p> <p>Results</p> <p>Seven per cent of the variation in obesity prevalence was at the neighbourhood level and the odds of being obese were almost doubled in poor areas.</p> <p>Conclusion</p> <p>Our findings supports a community approach in the prevention of obesity in general and thus also in pregnant women.</p