scholarly journals Risk of reinfection after seroconversion to SARS-CoV-2: A population-based propensity-score matched cohort study

2021 ◽  
Author(s):  
Antonio Leidi ◽  
Flora Koegler ◽  
Roxane Dumont ◽  
Richard Dubos ◽  
Maria-Eugenia Zaballa ◽  
...  
Keyword(s):  
Cohort Study ◽  
Propensity Score ◽  
Smoking Status ◽  
Large Population ◽  
Population Based ◽  
Matched Cohort ◽  
Igg Antibodies ◽  
Matched Cohort Study ◽  
Pandemic Wave

Importance: Serological assays detecting specific IgG antibodies generated against the Spike protein following Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection are being widely deployed in research studies and clinical practice. However, the duration and the effectiveness of the protection conferred by the immune response against future infection remains to be assessed in a large population. Objective: To estimate the incidence of newly acquired SARS-CoV-2 infections in seropositive individuals from a population-based sample as compared to seronegative controls. Design: Retrospective longitudinal propensity-score matched cohort study. Setting: A seroprevalence survey including a population-based representative sample of the population from the canton of Geneva (Switzerland) was conducted between April and June 2020, immediately after the first pandemic wave. Each individual included in the seroprevalence survey was linked to a state centralized registry compiling virologically confirmed SARS-CoV-2 infections since the beginning of the pandemic. Participants: Participants aged twelve years old and over, who developed anti-spike IgG antibodies were matched one-to-two to seronegative controls, using a propensity-score including age, gender, immunodeficiency, body mass index, smoking status and education level. Exposure: SARS-CoV-2 seropositivity. Main outcomes and measures: Our primary outcome was virologically confirmed SARS-CoV-2 infections which occurred from serological status assessment in April-June 2020 to the end of the second pandemic wave (January 2021). Additionally, incidence of infections, rate of testing and proportion of positive tests were analysed. Results: Among 8344 serosurvey participants, 498 seropositive individuals were selected and matched with 996 seronegative controls. After a mean follow-up of 35.6 (Standard Deviation, SD: 3.2) weeks, 7 out of 498 (1.4%) seropositive subjects had a positive SARS-CoV-2 test, of which 5 (1.0%) were considered as reinfections. By contrast, infection rate was significantly higher in seronegative individuals (15.5%, 154/996) during a similar mean follow-up of 34.7 (SD 3.2) weeks, corresponding to a 94% (95%CI 86% to 98%, P<0.001) reduction in the hazard of having a positive SARS-CoV-2 test for seropositive subjects. Conclusions and relevance: Seroconversion after SARS-CoV-2 infection confers protection to successive viral contamination lasting at least 8 months. These findings could help global health authorities establishing priority for vaccine allocation.

scholarly journals Differential cerebrovascular risks in glioblastoma and meningioma patients: a population-based matched cohort study in Wales (United Kingdom)

2021 ◽  
Vol 23 (Supplement_4) ◽  
pp. iv12-iv12
Author(s):  
Michael T C Poon ◽  
Kai Jin ◽  
Paul M Brennan ◽  
Jonine Figueroa ◽  
Cathie Sudlow
Keyword(s):  
Cohort Study ◽  
General Population ◽  
Ischaemic Stroke ◽  
Population Based ◽  
Parametric Models ◽  
Matched Cohort ◽  
Matched Cohort Study ◽  
Hazard Ratios ◽  
History Of

Abstract Aims There is limited evidence on cerebrovascular risks in glioblastoma and meningioma patients. We aimed to compare cerebrovascular risks of these patients with the general population. Method We used population-based routine healthcare and administrative data linkage in this matched cohort study. Cases were adult glioblastoma and meningioma patients diagnosed in Wales 2000-2014 identified in the cancer registry. Controls from cancer-free general population were matched to cases (5:1 ratio) on age (±5 years), sex and GP practice. Factors included in multivariable models were age, sex, index of multiple deprivation, hypertension, diabetes, high cholesterol, history of cardiovascular disease, and medications for cardiovascular diseases. Outcomes were fatal and non-fatal haemorrhagic and ischaemic stroke. We used flexible parametric models adjusting for confounders to calculate the hazard ratios (HR). Results Final analytic population was 16,921 participants, of which 1,340 had glioblastoma and 1,498 had meningioma. The median follow-up time was 0.5 year for glioblastoma patients, 4.9 years for meningioma patients, and 6.6 years for controls. The number of haemorrhage and ischaemic stroke was 154 and 374 in the glioblastoma matched cohort, respectively, and 180 and 569 in the meningioma matched cohort, respectively. The adjusted HRs for haemorrhagic and ischaemic stroke were 3.74 (95%CI 1.87-6.57) and 5.62 (95%CI 2.56-10.42) in glioblastoma patients, respectively, and were 2.42 (95%CI 1.58-3.52) and 1.86 (95%CI 1.54-2.23) in meningioma patients compared with their controls. Conclusion Glioblastoma and meningioma patients had higher cerebrovascular risks; these risks were even higher for glioblastoma patients. Further assessment of these potentially modifiable risks may improve survivorship.

scholarly journals 1402. Long-Term Mortality and Epilepsy in Patients After Brain Abscess: A Nationwide Population-based Matched Cohort Study

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S510-S510
Author(s):  
Jacob Bodilsen ◽  
Michael Dalager-Pedersen ◽  
Diederik van de Beek ◽  
Matthijs C Brouwer ◽  
Henrik Nielsen
Keyword(s):  
Cohort Study ◽  
Brain Abscess ◽  
Cox Regression ◽  
Population Based ◽  
Matched Cohort ◽  
Matched Cohort Study ◽  
Population Controls ◽  
New Onset

Abstract Background The long-term outcome of brain abscess is unclear. Methods We used medical registries to conduct a nationwide population-based matched cohort study to examine the long-term risks of mortality and new-onset epilepsy in patients hospitalized with brain abscess in Denmark from 1982 through 2016. Comparison cohorts from the same population individually matched on age, sex, and residence were identified, as were siblings of all study participants (Figure 1). We computed cumulative incidences and hazard rate ratios (HRRs) for mortality and new-onset epilepsy among brain abscess patients, comparison cohorts and siblings. Population and appendicitis controls had similar characteristics and prognosis why only comparisons between brain abscess patients and population controls are detailed here. Results We identified 1,384 brain abscess patients with a median follow-up time of 5.9 years (IQR 1.1–14.2). The 1-year, 2–5 year, and 6–30-year mortality of patients after brain abscess was 21%, 16% and 27% when compared with 1%, 6% and 20% for matched population controls (Figure 2). Cox regression analyses adjusted for Charlson comorbidity index score showed 1-year, 2–5 year, and 6- to 30-year HRRs of 17.5 (95% CI 13.9–22.2), 2.61 (95% CI 2.16–3.16) and 1.94 (95% CI 1.62–2.31). The mortality in brain abscess patients compared with population controls was significantly increased regardless of sex or age group except among subjects 80 years or older, and in both previously healthy individuals and immuno-compromised persons. Among the 30-day survivors of brain abscess (median follow-up 7.6 years [IQR 2.2–15.5]), new-onset epilepsy occurred in 32% compared with 2% in matched population controls. Cause-specific Cox regression analysis adjusted for stroke, head trauma, alcohol abuse, and cancer showed 1-year, 2–5-year, and 6–30-year HRRs for new-onset epilepsy of 155 (95% CI 78.8–304), 37.7 (95% CI 23.0–59.9), and 8.93 (95% CI 5.62–14.2) (Figure 3). Comparisons between sibling cohorts suggested no substantial effect of family-related factors on the long-term risk of death or epilepsy after brain abscess (Figure 4). Conclusion Brain abscess is associated with an increased long-term risk of mortality and new-onset epilepsy for several years after the acute infection. Disclosures All authors: No reported disclosures.

scholarly journals Variant-of-concern-attributable health and health system-related outcomes: a population-level propensity-score matched cohort study

2021 ◽  
Author(s):  
Aysegul Erman ◽  
Sharmistha Mishra ◽  
Kali Barrett ◽  
Stephen Mac ◽  
David MJ Naimark ◽  
...  
Keyword(s):  
Cohort Study ◽  
Propensity Score ◽  
Health Systems ◽  
Wild Type Strain ◽  
Severe Disease ◽  
Population Level ◽  
Population Based ◽  
Matched Cohort ◽  
Matched Cohort Study ◽  
Incident Laboratory

Background: As the transmission of SARS-CoV-2 variants intensifies globally, the burden of COVID-19 on the already strained health systems is becoming increasingly concerning. While there is growing literature on the effects of various variants-of-concern (VOC) on increased transmission, the extent to which VOCs may lead to more severe disease remains debated. Methods: In the current analysis, we use a population-based propensity-score matched cohort study of all incident laboratory-confirmed COVID-19 cases with VOC testing in Ontario, Canada to estimate healthcare resource use and health outcomes attributable to VOCs introduced to Ontario between January 1 and April 9, 2021, relative to the previously circulating wild-type strain. Results: We find that VOCs are associated with a higher odds of hospitalisation (odds ratio [OR], 2.25; 95% confidence interval [CI], 2.10-2.40) and ICU admission (OR, 3.31; 95%CI, 2.84-3.86); as well as with a higher odds of mortality for both the general COVID-19 population (OR 1.75; 1.47-2.09) and hospitalised cases (OR, 1.62; 95%CI, 1.23-2.15). Conclusion: Taken together, these findings suggest that health systems may face increased demand for healthcare resources as VOCs predominate worldwide in view of low global vaccination coverage.

scholarly journals Mortality Risk Associated with Haloperidol Use Compared with Other Antipsychotics: An 11-Year Population-Based Propensity-Score-Matched Cohort Study

CNS Drugs ◽  
2020 ◽  
Vol 34 (2) ◽  
pp. 197-206 ◽  
Author(s):  
Kim S. J. Lao ◽  
Angel Y. S. Wong ◽  
Ian C. K. Wong ◽  
Frank M. C. Besag ◽  
W. C. Chang ◽  
...  
Keyword(s):  
Cohort Study ◽  
Propensity Score ◽  
Mortality Risk ◽  
Population Based ◽  
Matched Cohort ◽  
Matched Cohort Study
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