scholarly journals 5. Improved Regression Estimation of a Multivariate Relationship with Population Data on the Bivariate Relationship

2005 ◽  
Vol 35 (1) ◽  
pp. 291-334 ◽  
Author(s):  
Mark S. Handcock ◽  
Michael S. Rendall ◽  
Jacob E. Cheadle
Keyword(s):  
White Women ◽  
Marital Fertility ◽  
Population Data ◽  
Population Level ◽  
Regression Coefficients ◽  
Sample Survey ◽  
Level Data ◽  
Multivariate Relationships ◽  
The Difference ◽  
Multivariate Relationship

Regression coefficients specify the partial effect of a regressor on the dependent variable. Sometimes the bivariate or limited multivariate relationship of that regressor variable with the dependent variable is known from population-level data. We show here that such population-level data can be used to reduce variance and bias about estimates of those regression coefficients from sample survey data. The method of constrained MLE is used to achieve these improvements. Its statistical properties are first described. The method constrains the weighted sum of all the covariate-specific associations (partial effects) of the regressors on the dependent variable to equal the overall association of one or more regressors, where the latter is known exactly from the population data. We refer to those regressors whose bivariate or limited multivariate relationships with the dependent variable are constrained by population data as being “directly constrained.” Our study investigates the improvements in the estimation of directly constrained variables as well as the improvements in the estimation of other regressor variables that may be correlated with the directly constrained variables, and thus “indirectly constrained” by the population data. The example application is to the marital fertility of black versus white women. The difference between white and black women's rates of marital fertility, available from population-level data, gives the overall association of race with fertility. We show that the constrained MLE technique both provides a far more powerful statistical test of the partial effect of being black and purges the test of a bias that would otherwise distort the estimated magnitude of this effect. We find only trivial reductions, however, in the standard errors of the parameters for indirectly constrained regressors.

scholarly journals Methodology of Natsal-COVID Wave 1: a large, quasi-representative survey with qualitative follow-up measuring the impact of COVID-19 on sexual and reproductive health in Britain

2021 ◽  
Vol 6 ◽  
pp. 209
Author(s):  
Emily Dema ◽  
Andrew J Copas ◽  
Soazig Clifton ◽  
Anne Conolly ◽  
Margaret Blake ◽  
...  
Keyword(s):  
General Population ◽  
Reproductive Health ◽  
Sexual Behaviour ◽  
Sexual And Reproductive Health ◽  
Service Use ◽  
Population Data ◽  
Population Level ◽  
Level Data ◽  
The Impact

Background: Britain’s National Surveys of Sexual Attitudes and Lifestyles (Natsal) have been undertaken decennially since 1990 and provide a key data source underpinning sexual and reproductive health (SRH) policy. The COVID-19 pandemic disrupted many aspects of sexual lifestyles, triggering an urgent need for population-level data on sexual behaviour, relationships, and service use at a time when gold-standard in-person, household-based surveys with probability sampling were not feasible. We designed the Natsal-COVID study to understand the impact of COVID-19 on the nation’s SRH and assessed the sample representativeness. Methods: Natsal-COVID Wave 1 data collection was conducted four months (29/7-10/8/2020) after the announcement of Britain’s first national lockdown (23/03/2020). This was an online web-panel survey administered by survey research company, Ipsos MORI. Eligible participants were resident in Britain, aged 18-59 years, and the sample included a boost of those aged 18-29. Questions covered participants’ sexual behaviour, relationships, and SRH service use. Quotas and weighting were used to achieve a quasi-representative sample of the British general population. Participants meeting criteria of interest and agreeing to recontact were selected for qualitative follow-up interviews. Comparisons were made with contemporaneous national probability surveys and Natsal-3 (2010-12) to understand bias. Results: 6,654 participants completed the survey and 45 completed follow-up interviews. The weighted Natsal-COVID sample was similar to the general population in terms of gender, age, ethnicity, rurality, and, among sexually-active participants, numbers of sexual partners in the past year. However, the sample was more educated, contained more sexually-inexperienced people, and included more people in poorer health. Conclusions: Natsal-COVID Wave 1 rapidly collected quasi-representative population data to enable evaluation of the early population-level impact of COVID-19 and lockdown measures on SRH in Britain and inform policy. Although sampling was less representative than the decennial Natsals, Natsal-COVID will complement national surveillance data and Natsal-4 (planned for 2022).

scholarly journals SARS-CoV-2 infection and COVID-19 vaccination rates in pregnant women in Scotland

2022 ◽  
Author(s):  
Sarah J. Stock ◽  
Jade Carruthers ◽  
Clara Calvert ◽  
Cheryl Denny ◽  
Jack Donaghy ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Vaccine Coverage ◽  
Population Data ◽  
Population Level ◽  
Vaccine Uptake ◽  
Female Population ◽  
Background Rate ◽  
Vaccination Rates ◽  
Level Data ◽  
Critical Care Admission

AbstractPopulation-level data on COVID-19 vaccine uptake in pregnancy and SARS-CoV-2 infection outcomes are lacking. We describe COVID-19 vaccine uptake and SARS-CoV-2 infection in pregnant women in Scotland, using whole-population data from a national, prospective cohort. Between the start of a COVID-19 vaccine program in Scotland, on 8 December 2020 and 31 October 2021, 25,917 COVID-19 vaccinations were given to 18,457 pregnant women. Vaccine coverage was substantially lower in pregnant women than in the general female population of 18−44 years; 32.3% of women giving birth in October 2021 had two doses of vaccine compared to 77.4% in all women. The extended perinatal mortality rate for women who gave birth within 28 d of a COVID-19 diagnosis was 22.6 per 1,000 births (95% CI 12.9−38.5; pandemic background rate 5.6 per 1,000 births; 452 out of 80,456; 95% CI 5.1−6.2). Overall, 77.4% (3,833 out of 4,950; 95% CI 76.2−78.6) of SARS-CoV-2 infections, 90.9% (748 out of 823; 95% CI 88.7−92.7) of SARS-CoV-2 associated with hospital admission and 98% (102 out of 104; 95% CI 92.5−99.7) of SARS-CoV-2 associated with critical care admission, as well as all baby deaths, occurred in pregnant women who were unvaccinated at the time of COVID-19 diagnosis. Addressing low vaccine uptake rates in pregnant women is imperative to protect the health of women and babies in the ongoing pandemic.

scholarly journals Gonorrhea testing, morbidity, and reporting using an integrated sexually transmitted disease registry in Indiana: 2004–2016

2020 ◽  
pp. 095646242095371
Author(s):  
Opeyemi C Ojo ◽  
Janet N Arno ◽  
Guoyu Tao ◽  
Chirag G Patel ◽  
Zuoyi Zhang ◽  
...  
Keyword(s):  
Sexually Transmitted Disease ◽  
Case Reports ◽  
Transmitted Disease ◽  
Population Level ◽  
The United States ◽  
Cross Sectional ◽  
Sexually Transmitted ◽  
Level Data ◽  
The Difference ◽  
Number Of Individuals

Surveillance of gonorrhea (GC), the second most common notifiable disease in the United States, depends on case reports. Population-level data that contain the number of individuals tested in addition to morbidity are lacking. We performed a cross-sectional analysis of data obtained from individuals tested for GC recorded in a sexually transmitted disease (STD) registry in the state of Indiana. Descriptive statistics were performed, and a Poisson generalized linear model was used to evaluate the number of individuals tested for GC and the positivity rate. GC cases from a subset of the registry were compared to CDC counts to determine the completeness of the registry. A total of 1,870,811 GC tests were linked to 627,870 unique individuals. Individuals tested for GC increased from 54,334 in 2004 to 269,701 in 2016; likewise, GC cases increased from 2,039 to 5,997. However, positivity rate decreased from 3.75% in 2004 to 2.22% in 2016. The difference in the number of GC cases captured by the registry and those reported to the CDC was not statistically significant (P = 0.0665). Population-level data from an STD registry combining electronic medical records and public health case data may inform STD control efforts. In Indiana, increased testing rates appeared to correlate with increased GC morbidity.

Cranial crassicaudiasis in two coastal dolphin species from South Africa is predominantly a disease of immature individuals

2020 ◽  
Vol 139 ◽  
pp. 93-102 ◽  
Author(s):  
MF Van Bressem ◽  
P Duignan ◽  
JA Raga ◽  
K Van Waerebeek ◽  
N Fraijia-Fernández ◽  
...  
Keyword(s):  
South Africa ◽  
Bone Development ◽  
Bottlenose Dolphins ◽  
Fatal Outcome ◽  
Population Level ◽  
Cape Coast ◽  
Osteolytic Lesions ◽  
Immune Mediated ◽  
Significant Difference ◽  
The Difference

Crassicauda spp. (Nematoda) infest the cranial sinuses of several odontocetes, causing diagnostic trabecular osteolytic lesions. We examined skulls of 77 Indian Ocean humpback dolphins Sousa plumbea and 69 Indo-Pacific bottlenose dolphins Tursiops aduncus, caught in bather-protecting nets off KwaZulu-Natal (KZN) from 1970-2017, and skulls of 6 S. plumbea stranded along the southern Cape coast in South Africa from 1963-2002. Prevalence of cranial crassicaudiasis was evaluated according to sex and cranial maturity. Overall, prevalence in S. plumbea and T. aduncus taken off KZN was 13 and 31.9%, respectively. Parasitosis variably affected 1 or more cranial bones (frontal, pterygoid, maxillary and sphenoid). No significant difference was found by gender for either species, allowing sexes to be pooled. However, there was a significant difference in lesion prevalence by age, with immature T. aduncus 4.6 times more likely affected than adults, while for S. plumbea, the difference was 6.5-fold. As severe osteolytic lesions are unlikely to heal without trace, we propose that infection is more likely to have a fatal outcome for immature dolphins, possibly because of incomplete bone development, lower immune competence in clearing parasites or an over-exuberant inflammatory response in concert with parasitic enzymatic erosion. Cranial osteolysis was not observed in mature males (18 S. plumbea, 21 T. aduncus), suggesting potential cohort-linked immune-mediated resistance to infestation. Crassicauda spp. may play a role in the natural mortality of S. plumbea and T. aduncus, but the pathogenesis and population level impact remain unknown.

scholarly journals Understanding and responding to COVID-19 in Wales: protocol for a privacy-protecting data platform for enhanced epidemiology and evaluation of interventions

BMJ Open ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. e043010
Author(s):  
Jane Lyons ◽  
Ashley Akbari ◽  
Fatemeh Torabi ◽  
Gareth I Davies ◽  
Laura North ◽  
...  
Keyword(s):  
Policy Development ◽  
Healthcare Utilisation ◽  
Population Data ◽  
Population Level ◽  
Risk Groups ◽  
Service Utilisation ◽  
Natural Experiments ◽  
Spread Of Infection ◽  
The Impact

IntroductionThe emergence of the novel respiratory SARS-CoV-2 and subsequent COVID-19 pandemic have required rapid assimilation of population-level data to understand and control the spread of infection in the general and vulnerable populations. Rapid analyses are needed to inform policy development and target interventions to at-risk groups to prevent serious health outcomes. We aim to provide an accessible research platform to determine demographic, socioeconomic and clinical risk factors for infection, morbidity and mortality of COVID-19, to measure the impact of COVID-19 on healthcare utilisation and long-term health, and to enable the evaluation of natural experiments of policy interventions.Methods and analysisTwo privacy-protecting population-level cohorts have been created and derived from multisourced demographic and healthcare data. The C20 cohort consists of 3.2 million people in Wales on the 1 January 2020 with follow-up until 31 May 2020. The complete cohort dataset will be updated monthly with some individual datasets available daily. The C16 cohort consists of 3 million people in Wales on the 1 January 2016 with follow-up to 31 December 2019. C16 is designed as a counterfactual cohort to provide contextual comparative population data on disease, health service utilisation and mortality. Study outcomes will: (a) characterise the epidemiology of COVID-19, (b) assess socioeconomic and demographic influences on infection and outcomes, (c) measure the impact of COVID-19 on short -term and longer-term population outcomes and (d) undertake studies on the transmission and spatial spread of infection.Ethics and disseminationThe Secure Anonymised Information Linkage-independent Information Governance Review Panel has approved this study. The study findings will be presented to policy groups, public meetings, national and international conferences, and published in peer-reviewed journals.

scholarly journals Population-Level Prevalence, Bother, and Treatment Behavior for Urinary Incontinence in an Eastern European Country: Findings from the LUTS POLAND Study

2021 ◽  
Vol 10 (11) ◽  
pp. 2314
Author(s):  
Mikolaj Przydacz ◽  
Marcin Chlosta ◽  
Piotr Chlosta
Keyword(s):  
Quality Of Life ◽  
Urinary Incontinence ◽  
Rural Areas ◽  
Eastern European Country ◽  
Population Level ◽  
Eastern European ◽  
Level Data ◽  
Urban And Rural Areas ◽  
Eastern European Countries

Objectives: Population-level data are lacking for urinary incontinence (UI) in Central and Eastern European countries. Therefore, the objective of this study was to estimate the prevalence, bother, and behavior regarding treatment for UI in a population-representative group of Polish adults aged ≥ 40 years. Methods: Data for this epidemiological study were derived from the larger LUTS POLAND project, in which a group of adults that typified the Polish population were surveyed, by telephone, about lower urinary tract symptoms. Respondents were classified by age, sex, and place of residence. UI was assessed with a standard protocol and established International Continence Society definitions. Results: The LUTS POLAND survey included 6005 completed interviews. The prevalence of UI was 14.6–25.4%; women reported a greater occurrence compared with men (p < 0.001). For both sexes, UI prevalence increased with age. Stress UI was the most common type of UI in women, and urgency UI was the most prevalent in men. We did not find a difference in prevalence between urban and rural areas. Individuals were greatly bothered by UI. For women, mixed UI was the most bothersome, whereas for men, leak for no reason was most annoying. More than half of respondents (51.4–62.3%) who reported UI expressed anxiety about the effect of UI on their quality of life. Nevertheless, only around one third (29.2–38.1%) of respondents with UI sought treatment, most of whom received treatment. Persons from urban and rural areas did not differ in the degrees of treatment seeking and treatment receiving. Conclusion: Urinary incontinence was prevalent and greatly bothersome among Polish adults aged ≥ 40 years. Consequently, UI had detrimental effects on quality of life. Nonetheless, most affected persons did not seek treatment. Therefore, we need to increase population awareness in Poland about UI and available treatment methods, and we need to ensure adequate allocation of government and healthcare system resources.

scholarly journals The domestication of Cucurbita argyrosperma as revealed by the genome of its wild relative

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Josué Barrera-Redondo ◽  
Guillermo Sánchez-de la Vega ◽  
Jonás A. Aguirre-Liguori ◽  
Gabriela Castellanos-Morales ◽  
Yocelyn T. Gutiérrez-Guerrero ◽  
...  
Keyword(s):  
Defense Mechanisms ◽  
Population Level ◽  
Growth Hormones ◽  
Comparative Genomic ◽  
Structural Variants ◽  
Closely Related Species ◽  
Level Data ◽  
Genomic Analyses ◽  
Genotype By Sequencing ◽  
Regulation Of Growth

AbstractDespite their economic importance and well-characterized domestication syndrome, the genomic impact of domestication and the identification of variants underlying the domestication traits in Cucurbita species (pumpkins and squashes) is currently lacking. Cucurbita argyrosperma, also known as cushaw pumpkin or silver-seed gourd, is a Mexican crop consumed primarily for its seeds rather than fruit flesh. This makes it a good model to study Cucurbita domestication, as seeds were an essential component of early Mesoamerican diet and likely the first targets of human-guided selection in pumpkins and squashes. We obtained population-level data using tunable Genotype by Sequencing libraries for 192 individuals of the wild and domesticated subspecies of C. argyrosperma across Mexico. We also assembled the first high-quality wild Cucurbita genome. Comparative genomic analyses revealed several structural variants and presence/absence of genes related to domestication. Our results indicate a monophyletic origin of this domesticated crop in the lowlands of Jalisco. We found evidence of gene flow between the domesticated and wild subspecies, which likely alleviated the effects of the domestication bottleneck. We uncovered candidate domestication genes that are involved in the regulation of growth hormones, plant defense mechanisms, seed development, and germination. The presence of shared selected alleles with the closely related species Cucurbita moschata suggests domestication-related introgression between both taxa.

Study on Association between Height, Weight, Iodine Supplementation and Thyroid Volume

2021 ◽  
pp. 1-25
Author(s):  
Lanchun Liu ◽  
Lixiang Liu ◽  
Ming Li ◽  
Yang Du ◽  
Peng Liu ◽  
...  
Keyword(s):  
Iodine Deficiency ◽  
Linear Models ◽  
Thyroid Volume ◽  
Salt Iodization ◽  
Iodine Supplementation ◽  
Random Pairing ◽  
Level Data ◽  
The Mean ◽  
Salt Iodine ◽  
The Difference

Abstract The policy of Universal Salt Iodization (USI) could reduce population’s thyroid volume (TVOL) in iodine deficiency areas. Conversely, the improved growth and developmental status of children might increase the TVOL accordingly. Whether the decreased TVOL by USI conceals the increase effect of height and weight on TVOL is unclear. The aim of this study was to analyse the association between height, weight, iodine supplementation and TVOL. Five national Iodine Deficiency Disorder surveys were matched into four pairs according to the purpose of analysis. County-level data of both detected by paired surveys were incorporated, 1: 1 random pairing method was used to match counties or individuals. The difference of TVOL between different height, weight, different iodine supplementation measures groups and the association between TVOL and them were studied. The mean height and weight of children aged 8-10 years increased from 129.9cm and 26.9kg in 2002 to 136.2cm and 32.1kg in 2019; while the median TVOL decreased from 3.10ml to 2.61ml. Iodine supplementation measures can affect TVOL; after exclude iodine effects, the median TVOL was increased with the height and weight. On the other side, after excluding the influence of height and weight, the median TVOL remained decreased. Only age, weight and salt iodine were significant associated with TVOL in multiple linear models. Development of height and weight in children is the evidence of improved nutrition. The decreased TVOL caused by iodized salt measures conceals the increase effect of height and weight on TVOL. Age, weight, and salt iodine affect TVOL significantly.

Sign in / Sign up

Export Citation Format

Share Document