scholarly journals Safety of Pfizer-BioNTech vaccine in a cohort of healthcare providers: differences between naïve and previously infected.

2021 ◽  
Author(s):  
ANDREA CHONG VALBUENA ◽  
Isabel De-Jesus-Maria ◽  
Adriana Agurto-Ramírez ◽  
Francesc Puchades Gimeno ◽  
Mercedes Melero-García
Keyword(s):  
Cohort Study ◽  
Adverse Events ◽  
Retrospective Cohort ◽  
Healthcare Workers ◽  
Healthcare Providers ◽  
Absolute Number ◽  
Past Infection ◽  
Spanish Society ◽  
Relative Risks ◽  
History Of

Introduction: The Spanish Society of Immunology recently warned that a history of past COVID-19 could result in a higher incidence of adverse events (AEs) related to vaccination. We set out to analyze whether there were any differences in AEs between healthcare workers vaccinated for COVID-19 (either after the first or second dose) who had had a prior diagnosis SARS-CoV-2 infection compared to those who had not had COVID-19 before vaccination. Methods: This was a retrospective cohort study in a population of healthcare workers. AEs related to the first and second doses of the Pfizer vaccine were recorded. We compared the incidence of AEs and compared individuals with 0–3 different AEs to those with 4 or more AEs. The relative risks (RR) and their 95% confidence intervals were calculated. Results: Past infection was associated with having more AEs after the first dose (p < 0.001), but not the second one (p = 0.476), as well as a higher incidence of AEs (p < 0.001). Common AEs that were statistically associated with past COVID infection included arthralgia, asthenia, fever, chills, headache, and myalgia (p ≤ 0.001). The RR for having an increased absolute number of different AEs was 1.18 (95%CI [1.05, 1.33]) after the first dose and 1.05 (95%CI [0.96, 1.14]) after the second dose. Conclusions: Our results showed that the incidence of AEs was higher in individuals with a history of prior COVID-19 infection.

scholarly journals Reinfection Rates Among Patients Who Previously Tested Positive for Coronavirus Disease 2019: A Retrospective Cohort Study

2021 ◽  
Author(s):  
Megan M Sheehan ◽  
Anita J Reddy ◽  
Michael B Rothberg
Keyword(s):  
Cohort Study ◽  
Retrospective Cohort Study ◽  
Retrospective Cohort ◽  
Symptomatic Infection ◽  
Symptomatic Disease ◽  
Viral Shedding ◽  
History Of ◽  
Polymerase Chain ◽  
Prior Infection ◽  
Over Time

Abstract Background Protection afforded from prior disease among patients with coronavirus disease 2019 (COVID-19) infection is unknown. If infection provides substantial long-lasting immunity, it may be appropriate to reconsider vaccination distribution. Methods This retrospective cohort study of 1 health system included 150 325 patients tested for COVID-19 infection via polymerase chain reaction from 12 March 2020 to 30 August 2020. Testing performed up to 24 February 2021 in these patients was included. The main outcome was reinfection, defined as infection ≥90 days after initial testing. Secondary outcomes were symptomatic infection and protection of prior infection against reinfection. Results Of 150 325 patients, 8845 (5.9%) tested positive and 141 480 (94.1%) tested negative before 30 August. A total of 1278 (14.4%) positive patients were retested after 90 days, and 62 had possible reinfection. Of those, 31 (50%) were symptomatic. Of those with initial negative testing, 5449 (3.9%) were subsequently positive and 3191 of those (58.5%) were symptomatic. Protection offered from prior infection was 81.8% (95% confidence interval [CI], 76.6–85.8) and against symptomatic infection was 84.5% (95% CI, 77.9–89.1). This protection increased over time. Conclusions Prior infection in patients with COVID-19 was highly protective against reinfection and symptomatic disease. This protection increased over time, suggesting that viral shedding or ongoing immune response may persist beyond 90 days and may not represent true reinfection. As vaccine supply is limited, patients with known history of COVID-19 could delay early vaccination to allow for the most vulnerable to access the vaccine and slow transmission.

scholarly journals Adverse events in a Tunisian hospital: results of a retrospective cohort study

2010 ◽  
Vol 22 (5) ◽  
pp. 380-385 ◽  
Author(s):  
Mondher Letaief ◽  
Sana El Mhamdi ◽  
Riham El-Asady ◽  
Sameen Siddiqi ◽  
Ahmed Abdullatif
Keyword(s):  
Cohort Study ◽  
Adverse Events ◽  
Retrospective Cohort Study ◽  
Retrospective Cohort

scholarly journals Comparison of two methods to estimate adverse events in the IBEAS Study (Ibero-American study of adverse events): cross-sectional versus retrospective cohort design

BMJ Open ◽  
2017 ◽  
Vol 7 (10) ◽  
pp. e016546 ◽  
Author(s):  
Jesus Maria Aranaz Andrés ◽  
Ramon Limón Ramírez ◽  
Carlos Aibar Remón ◽  
Maria Teresa Gea-Velázquez de Castro ◽  
Francisco Bolúmar ◽  
...  
Keyword(s):  
Cohort Study ◽  
Adverse Events ◽  
Retrospective Cohort Study ◽  
Medical Records ◽  
Retrospective Cohort ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Hospital Size ◽  
Cohort Design ◽  
Cohort Study Design

BackgroundAdverse events (AEs) epidemiology is the first step to improve practice in the healthcare system. Usually, the preferred method used to estimate the magnitude of the problem is the retrospective cohort study design, with retrospective reviews of the medical records. However this data collection involves a sophisticated sampling plan, and a process of intensive review of sometimes very heavy and complex medical records. Cross-sectional survey is also a valid and feasible methodology to study AEs.ObjectivesThe aim of this study is to compare AEs detection using two different methodologies: cross-sectional versus retrospective cohort design.SettingSecondary and tertiary hospitals in five countries: Argentina, Colombia, Costa Rica, Mexico and Peru.ParticipantsThe IBEAS Study is a cross-sectional survey with a sample size of 11 379 patients. The retrospective cohort study was obtained from a 10% random sample proportional to hospital size from the entire IBEAS Study population.MethodsThis study compares the 1-day prevalence of the AEs obtained in the IBEAS Study with the incidence obtained through the retrospective cohort study.ResultsThe prevalence of patients with AEs was 10.47% (95% CI 9.90 to 11.03) (1191/11 379), while the cumulative incidence of the retrospective cohort study was 19.76% (95% CI 17.35% to 22.17%) (215/1088). In both studies the highest risk of suffering AEs was seen in Intensive Care Unit (ICU) patients. Comorbid patients and patients with medical devices showed higher risk.ConclusionThe retrospective cohort design, although requires more resources, allows to detect more AEs than the cross-sectional design.

scholarly journals Survival and prognostic factors in HIV-infected adults treated with Antiretroviral Therapy in a Malaysian referral hospital: A retrospective cohort study

2019 ◽  
Author(s):  
Lee Sing Chet ◽  
Siti Azrin Ab Hamid ◽  
Norsa'adah Bachok ◽  
Suresh Kumar Chidambaram
Keyword(s):  
Overall Survival ◽  
Cohort Study ◽  
Prognostic Factors ◽  
Antiretroviral Therapy ◽  
Haemoglobin Level ◽  
Retrospective Cohort ◽  
Survival Rates ◽  
Baseline Haemoglobin ◽  
History Of ◽  
Overall Survival Rates

Abstract Background: It is well established that antiretroviral therapy (ART) is beneficial in reducing the mortality among patients with human immunodeficiency virus (HIV). In Malaysia, there is lack of study and information regarding the overall survival rates and prognostic factors for survival in HIV-infected adults treated with ART. Therefore, this study aimed to assess and compare the survival rates as well as to identify the prognostic factors for survival among HIV adults in Malaysia.Methods: A retrospective cohort study was conducted by reviewing the medical records of HIV patients who started ART between year 2007 and 2016 at a tertiary referral hospital in Malaysia. ART-naive adults aged 15 years and above were included and those who were transferred out were excluded. After applying inclusion and exclusion criteria, there were 339 cases eligible in this study. Systematic sampling method was applied. Kaplan Meier survival curve and log-rank test were used to compare the overall survival rates. Cox proportional hazards regression was applied to determine the prognostic factors for survival.Results: The estimated overall survival rates were 95.9%, 93.8%, 90.4%, 84.9%, and 72.8% at 6 months, 1 year, 3 years, 5 years and 10 years, respectively. The overall survival rates were significantly different according to age group (p<0.001), employment status (p<0.001), transmission mode (p=0.003), and history of illicit drug use (p=0.017), baseline CD4 cell count (p<0.001), baseline haemoglobin level (p<0.001), tuberculosis co-infection (p<0.001), hepatitis co-infection (p=0.008), first NRTI (p<0.001) and history of defaults (p=0.021). Based on multiple Cox regression, patients who were anaemic had 3.76 times (95% CI: 1.97, 7.18; p<0.001) higher hazard of death than their non-anaemic counterparts. The hazard risk was 2.09 times (95% CI: 1.10, 3.96; p=0.024) higher among HIV patients co-infected with tuberculosis compared to those who were not. Conclusion: Overall survival rates were higher than low-income countries but lower than in high-income countries, and comparable with middle-income countries. Low baseline haemoglobin level and tuberculosis co-infection were strong prognostic factors for HIV survival

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