Thomas Benfield

Prof. Thomas Benfield

orcid

Research Focus & Metrics

Academic Career Length

33Years (1994-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 March 2021 in Annals of Internal Medicine
Verified
Journal Article
Open access
HBHenning Bundgaard
Henning Bundgaard
JBJohan Bundgaard
Johan Bundgaard
DRDaniel Emil Tadeusz Raaschou-Pedersen
Daniel Emil Tadeusz Raaschou-Pedersen
Christian von BuchwaldChristian von Buchwald
Christian von Buchwald
Tobias TodsenTobias Todsen
Tobias Todsen
KIKasper Iversen
Kasper Iversen
Observational evidence suggests that mask wearing mitigates SARS-CoV-2 transmission. It is uncertain if this observed association arises through protection of uninfected wearers (protective effect)... Visual Effectiveness of Mask Recommendation for Preventing SARS-CoV-2 Infection Observational evidence suggests that mask wearing mitigates SARS-CoV-2 transmission. It is uncertain if this... Background: Observational evidence suggests that mask wearing mitigates transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It is uncertain if this observed association ar...

16 July 2014 in Clinical Infectious Diseases
Verified
Journal Article
Open access
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Zitta F B Barrella HarboeZitta F B Barrella Harboe
Zitta F B Barrella Harboe
Tine DalbyTine Dalby
Tine Dalby
DWDaniel M. Weinberger
Daniel M. Weinberger
TBThomas Benfield
Thomas Benfield
KMKåre Mølbak
Kåre Mølbak
PVPalle Valentiner-Branth
Palle Valentiner-Branth
Background. The impact of the 13-valent pneumococcal conjugate vaccine (PCV13) at the population level is unclear. We explored PCV13's effect in reducing invasive pneumococcal disease (IPD)–related morbidity and mortality, and whether serotype-specific changes were attributable to vaccination or expected as a part of natural, cyclical variations. Methods. This was a Danish nationwide population-based cohort study based on the linkage of laboratory surveillance data and the Danish Civil Registration System. Changes in IPD incidence and mortality during baseline (2000–2007), 7-valent pneumococcal conjugate vaccine (PCV7) (2008–2010), and PCV13 (2011–2013) periods were estimated. Predicted incidences of serotypes were estimated controlling for cyclical trends from historical patterns observed during the past 20 years. Results. We observed a 21% reduction (95% confidence interval [CI], 17%–25%) in IPD incidence in the total population after PCV13's introduction, and a 71% reduction (95% CI, 62%–79%) in children aged <2 years, considered as the vaccine effectiveness. We estimated a 28% reduction (95% CI, 18%–37%) in IPD-related 30-day mortality, from 3.4 deaths (95% CI, 3.2–3.6) per 100 000 population in the pre-PCV period to 2.4 (95% CI, 2.2–2.7) in the PCV13 period. The decline in mortality was observed across all age groups but was mainly related to mortality reductions in the nonvaccinated population. For serotypes 1 and 3, there were no significant changes in incidence beyond what would be expected from natural cyclical patterns. Serotype 19A significantly increased following PCV7's introduction, but the incidence declined toward baseline in 2012. Conclusions. PCV13 has brought greater benefits than we had expected in our setting. We observed a further decline on IPD incidence shortly after the shift from PCV7 to PCV13 in the national immunization program. This decline was accompanied by a substantial population-level decline in pneumococcal-related mortality of nearly 30% among nonvaccinated persons.

26 May 2009 in PLOS Medicine
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Zitta F B Barrella HarboeZitta F B Barrella Harboe
Zitta F B Barrella Harboe
RTReimar W Thomsen
Reimar W Thomsen
ARAnders Riis
Anders Riis
PVPalle Valentiner-Branth
Palle Valentiner-Branth
JCJens Jørgen Christensen
Jens Jørgen Christensen
TBThomas Benfield
Thomas Benfield
Pneumococcal disease is a leading cause of morbidity and mortality worldwide. The aim of this study was to investigate the association between specific pneumococcal serotypes and mortality from invasive pneumococcal disease (IPD). In a nationwide population-based cohort study of IPD in Denmark during 1977–2007, 30-d mortality associated with pneumococcal serotypes was examined by multivariate logistic regression analysis after controlling for potential confounders. A total of 18,858 IPD patients were included. Overall 30-d mortality was 18%, and 3% in children younger than age 5 y. Age, male sex, meningitis, high comorbidity level, alcoholism, and early decade of diagnosis were significantly associated with mortality. Among individuals aged 5 y and older, serotypes 31, 11A, 35F, 17F, 3, 16F, 19F, 15B, and 10A were associated with highly increased mortality as compared with serotype 1 (all: adjusted odds ratio ≥3, p<0.001). In children younger than 5 y, associations between serotypes and mortality were different than in adults but statistical precision was limited because of low overall childhood-related mortality. Specific pneumococcal serotypes strongly and independently affect IPD associated mortality.

23 December 2006 in Diabetologia
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Journal Article
Closed access
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TBThomas Benfield
Thomas Benfield
JJJ. S. Jensen
J. S. Jensen
BNB. G. Nordestgaard
B. G. Nordestgaard

15 April 2021 in Nature Communications
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Journal Article
Open access
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CACathrine Axfors
Cathrine Axfors
ASAndreas M. Schmitt
Andreas M. Schmitt
PJPerrine Janiaud
Perrine Janiaud
JHJanneke Van’t Hooft
Janneke Van’t Hooft
SASherief Abd-Elsalam
Sherief Abd-Elsalam
LHLars Hemkens
Lars Hemkens
Substantial COVID-19 research investment has been allocated to randomized clinical trials (RCTs) on hydroxychloroquine/chloroquine, which currently face recruitment challenges or early discontinuation. We aim to estimate the effects of hydroxychloroquine and chloroquine on survival in COVID-19 from all currently available RCT evidence, published and unpublished. We present a rapid meta-analysis of ongoing, completed, or discontinued RCTs on hydroxychloroquine or chloroquine treatment for any COVID-19 patients (protocol: https://osf.io/QESV4/). We systematically identified unpublished RCTs (ClinicalTrials.gov, WHO International Clinical Trials Registry Platform, Cochrane COVID-registry up to June 11, 2020), and published RCTs (PubMed, medRxiv and bioRxiv up to October 16, 2020). All-cause mortality has been extracted (publications/preprints) or requested from investigators and combined in random-effects meta-analyses, calculating odds ratios (ORs) with 95% confidence intervals (CIs), separately for hydroxychloroquine and chloroquine. Prespecified subgroup analyses include patient setting, diagnostic confirmation, control type, and publication status. Sixty-three trials were potentially eligible. We included 14 unpublished trials (1308 patients) and 14 publications/preprints (9011 patients). Results for hydroxychloroquine are dominated by RECOVERY and WHO SOLIDARITY, two highly pragmatic trials, which employed relatively high doses and included 4716 and 1853 patients, respectively (67% of the total sample size). The combined OR on all-cause mortality for hydroxychloroquine is 1.11 (95% CI: 1.02, 1.20; I² = 0%; 26 trials; 10,012 patients) and for chloroquine 1.77 (95%CI: 0.15, 21.13, I² = 0%; 4 trials; 307 patients). We identified no subgroup effects. We found that treatment with hydroxychloroquine is associated with increased mortality in COVID-19 patients, and there is no benefit of chloroquine. Findings have unclear generalizability to outpatients, children, pregnant women, and people with comorbidities.

1 March 2010 in American Journal of Respiratory and Critical Care Medicine
Verified
Journal Article
Closed access
CAClaire Andréjak
Claire Andréjak
VTVibeke Ø. Thomsen
Vibeke Ø. Thomsen
IJIsik Somuncu Johansen
Isik Somuncu Johansen
ARAnders Riis
Anders Riis
TBThomas Benfield
Thomas Benfield
RTReimar W. Thomsen
Reimar W. Thomsen
Rationale: Few population-based data are available regarding nontuberculous mycobacteria (NTM) pulmonary disease epidemiology and prognosis. Objectives: To examine NTM pulmonary colonization incidence, disease incidence, and prognostic factors. Methods: All adults in Denmark with at least one NTM-positive pulmonary specimen during 1997 to 2008 were identified using national medical databases and were categorized as having possible or definite NTM disease or colonization. Measurements and Main Results: We calculated annual age-standardized NTM incidence rates and adjusted hazard ratios (HR) of death associated with patient age, sex, comorbidity, NTM species, and NTM disease status. Of 1,282 adults with 2,666 NTM-positive pulmonary specimens, 335 (26%) had definite NTM disease, 238 (19%) possible disease, and 709 (55%) colonization only. NTM incidence rates decreased until 2002, followed by an increase from 2003 to 2008 (mean annual rate per 100,000 person-years: NTM colonization, 1.36; NTM disease, 1.08). Five-year mortality after definite NTM disease was 40.1%. After controlling for potential confounders, 5-year mortality for definite NTM disease was slightly higher than for NTM colonization (adjusted hazard ratio [HR], 1.15; 95% confidence interval [CI], 0.90–1.51). Mycobacterium xenopi was associated with worse prognosis (adjusted HR, 1.51; 95% CI, 0.99–2.33) than the reference Mycobacterium avium complex. High comorbidity level (HR, 2.97), age greater than or equal to 65 years (HR, 9.17), and male sex (female sex HR, 0.73) were predictors of death. Conclusions: NTM disease incidence has remained unchanged in Denmark over the past 12 years. Patients with NTM colonization and disease have similarly poor prognosis. Negative prognostic factors include high levels of comorbidity, advanced age, male sex, and M. xenopi.