Allometry Between Measures of Body Size and Shape in a Large Population-Based Cohort

Background: Prednisone is a common treatment for myasthenia gravis (MG), and osteoporosis is a known potential risk of chronic prednisone therapy. Objective: Our aim was to evaluate the risk of serious fractures in a population-based cohort of MG patients. Methods: An inception cohort of patients with MG was identified from administrative health data in Ontario, Canada between April 1, 2002 and December 31, 2015. For each MG patient, we matched 4 general population comparators based on age, sex, and region of residence. Fractures were identified through emergency department and hospitalization data. Crude overall rates and sex-specific rates of fractures were calculated for the MG and comparator groups, as well as rates of specific fractures. Adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox regression. Results: Among 3,823 incident MG patients (followed for a mean of 5 years), 188 (4.9%) experienced a fracture compared with 741 (4.8%) fractures amongst 15,292 matched comparators. Crude fracture rates were not different between the MG cohort and matched comparators (8.71 vs. 7.98 per 1000 patient years), overall and in men and women separately. After controlling for multiple covariates, MG patients had a significantly lower risk of fracture than comparators (HR 0.74, 95% CI 0.63–0.88). Conclusions: In this large, population-based cohort of incident MG patients, MG patients were at lower risk of a major fracture than comparators. The reasons for this finding are unclear but may highlight the importance osteoporosis prevention.

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Estimating the asymptomatic proportion of SARS-CoV-2 infection in the general population: Analysis of nationwide serosurvey data in the Netherlands

European Journal of Epidemiology ◽

10.1007/s10654-021-00768-y ◽

2021 ◽

Author(s):

Scott A. McDonald ◽

Fuminari Miura ◽

Eric R. A. Vos ◽

Michiel van Boven ◽

Hester E. de Melker ◽

...

Keyword(s):

The Netherlands ◽

Population Analysis ◽

Large Population ◽

Population Based ◽

Attributable Risk ◽

Case Definition ◽

Aggregated Data ◽

Age Dependent ◽

Additive Regression ◽

June July

Abstract Background The proportion of SARS-CoV-2 positive persons who are asymptomatic—and whether this proportion is age-dependent—are still open research questions. Because an unknown proportion of reported symptoms among SARS-CoV-2 positives will be attributable to another infection or affliction, the observed, or 'crude' proportion without symptoms may underestimate the proportion of persons without symptoms that are caused by SARS-CoV-2 infection. Methods Based on two rounds of a large population-based serological study comprising test results on seropositivity and self-reported symptom history conducted in April/May and June/July 2020 in the Netherlands (n = 7517), we estimated the proportion of reported symptoms among those persons infected with SARS-CoV-2 that is attributable to this infection, where the set of relevant symptoms fulfills the ECDC case definition of COVID-19, using inferential methods for the attributable risk (AR). Generalised additive regression modelling was used to estimate the age-dependent relative risk (RR) of reported symptoms, and the AR and asymptomatic proportion (AP) were calculated from the fitted RR. Results Using age-aggregated data, the 'crude' AP was 37% but the model-estimated AP was 65% (95% CI 63–68%). The estimated AP varied with age, from 74% (95% CI 65–90%) for < 20 years, to 61% (95% CI 57–65%) for the 50–59 years age-group. Conclusion Whereas the 'crude' AP represents a lower bound for the proportion of persons infected with SARS-CoV-2 without COVID-19 symptoms, the AP as estimated via an attributable risk approach represents an upper bound. Age-specific AP estimates can inform the implementation of public health actions such as targetted virological testing and therefore enhance containment strategies.

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From Multiplex Serology to Serolomics—A Novel Approach to the Antibody Response against the SARS-CoV-2 Proteome

Viruses ◽

10.3390/v13050749 ◽

2021 ◽

Vol 13 (5) ◽

pp. 749

Author(s):

Julia Butt ◽

Rajagopal Murugan ◽

Theresa Hippchen ◽

Sylvia Olberg ◽

Monique van Straaten ◽

...

Keyword(s):

Antibody Response ◽

High Throughput ◽

Large Population ◽

High Sensitivity ◽

Population Based ◽

Antibody Responses ◽

Hek293 Cells ◽

Novel Approach ◽

Assay Performance ◽

Multiplex Serology

The emerging SARS-CoV-2 pandemic entails an urgent need for specific and sensitive high-throughput serological assays to assess SARS-CoV-2 epidemiology. We, therefore, aimed at developing a fluorescent-bead based SARS-CoV-2 multiplex serology assay for detection of antibody responses to the SARS-CoV-2 proteome. Proteins of the SARS-CoV-2 proteome and protein N of SARS-CoV-1 and common cold Coronaviruses (ccCoVs) were recombinantly expressed in E. coli or HEK293 cells. Assay performance was assessed in a COVID-19 case cohort (n = 48 hospitalized patients from Heidelberg) as well as n = 85 age- and sex-matched pre-pandemic controls from the ESTHER study. Assay validation included comparison with home-made immunofluorescence and commercial enzyme-linked immunosorbent (ELISA) assays. A sensitivity of 100% (95% CI: 86–100%) was achieved in COVID-19 patients 14 days post symptom onset with dual sero-positivity to SARS-CoV-2 N and the receptor-binding domain of the spike protein. The specificity obtained with this algorithm was 100% (95% CI: 96–100%). Antibody responses to ccCoVs N were abundantly high and did not correlate with those to SARS-CoV-2 N. Inclusion of additional SARS-CoV-2 proteins as well as separate assessment of immunoglobulin (Ig) classes M, A, and G allowed for explorative analyses regarding disease progression and course of antibody response. This newly developed SARS-CoV-2 multiplex serology assay achieved high sensitivity and specificity to determine SARS-CoV-2 sero-positivity. Its high throughput ability allows epidemiologic SARS-CoV-2 research in large population-based studies. Inclusion of additional pathogens into the panel as well as separate assessment of Ig isotypes will furthermore allow addressing research questions beyond SARS-CoV-2 sero-prevalence.

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Determinant Factors of Poor Adherence to Iron Supplementation among Pregnant Women in Ethiopia: A large population-based study

Heliyon ◽

10.1016/j.heliyon.2021.e07530 ◽

2021 ◽

pp. e07530

Author(s):

Enyew Getaneh Mekonen ◽

Samrawit Abebe Alemu

Keyword(s):

Pregnant Women ◽

Iron Supplementation ◽

Large Population ◽

Population Based ◽

Poor Adherence ◽

Population Based Study ◽

Determinant Factors

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Melanoma is associated with an increased risk of bullous pemphigoid: a large population-based longitudinal study

Archives of Dermatological Research ◽

10.1007/s00403-021-02211-4 ◽

2021 ◽

Author(s):

Khalaf Kridin ◽

Jennifer E. Hundt ◽

Ralf J. Ludwig ◽

Kyle T. Amber ◽

Dana Tzur Bitan ◽

...

Keyword(s):

Bullous Pemphigoid ◽

Statistical Significance ◽

Large Population ◽

Underlying Mechanism ◽

Population Based ◽

Control Subjects ◽

Increased Risk ◽

Bidirectional Association ◽

History Of ◽

Incident Cases

AbstractThe association between bullous pemphigoid (BP) and melanoma is yet to be investigated. We aimed to assess assess the bidirectional association between BP and melanoma and to delineate the epidemiological features of patients with both diagnoses. A population-based cohort study was performed comparing BP patients (n = 3924) with age-, sex- and ethnicity-matched control subjects (n = 19,280) with regard to incident cases of melanoma. A case–control design was additionally adopted to estimate the risk of BP in individuals with a preexisting diagnosis of melanoma. The prevalence of preexisting melanoma was higher in patients with BP than in control subjects (1.5% vs. 1.0%, respectively; P = 0.004). A history of melanoma confers a 50% increase in the risk of subsequent BP (OR 1.53; 95% CI 1.14–2.06). This risk was higher among males (OR 1.66; 95% CI 1.09–2.54) and individuals older than 80 years (OR 1.63; 95% CI 1.11–2.38), and persisted after adjustment for multiple putative confounders including PD-1/PDL-1 antagonists (adjusted OR 1.53; 95% CI 1.14–2.06). Conversely, the risk of melanoma among patients with BP was slightly elevated, but did not reach the level of statistical significance (adjusted HR 1.13; 95% CI 0.73–1.74). Patients with a dual diagnosis of BP and melanoma were older at the onset of BP and had lower body mass index. A history of melanoma is associated with a 50% increase in the incidence of subsequent BP. Physicians managing patients with both conditions should be aware of this association. Further research is warranted to reveal the underlying mechanism of these findings.

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Incidence of patients with bone metastases at diagnosis of solid tumors in adults: a large population-based study

Annals of Translational Medicine ◽

10.21037/atm.2020.03.55 ◽

2020 ◽

Vol 8 (7) ◽

pp. 482-482 ◽

Cited By ~ 3

Author(s):

Jin-Feng Huang ◽

Jianfei Shen ◽

Xiao Li ◽

Ramesh Rengan ◽

Nicola Silvestris ◽

...

Keyword(s):

Bone Metastases ◽

Solid Tumors ◽

Large Population ◽

Population Based ◽

Population Based Study

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