Zobrazeno 1 - 10
of 251
pro vyhledávání: '"James R. Carpenter"'
Publikováno v:
BMC Medical Research Methodology, Vol 24, Iss 1, Pp 1-15 (2024)
Abstract Background Epidemiological and clinical studies often have missing data, frequently analysed using multiple imputation (MI). In general, MI estimates will be biased if data are missing not at random (MNAR). Bias due to data MNAR can be reduc
Externí odkaz:
https://doaj.org/article/bb793e936f3a43539a818fc58f0ebf47
Publikováno v:
BMC Medicine, Vol 22, Iss 1, Pp 1-20 (2024)
Abstract The use of digital health technologies to measure outcomes in clinical trials opens new opportunities as well as methodological challenges. Digital outcome measures may provide more sensitive and higher-frequency measurements but pose vital
Externí odkaz:
https://doaj.org/article/dcfc105241e64a0992bb08b2f5e72691
Autor:
Mia S. Tackney, Amber Steele, Joseph Newman, Marie-Christine Fritzsche, Federica Lucivero, Zarnie Khadjesari, Jennifer Lynch, Rosemary A. Abbott, Vicki S. Barber, James R. Carpenter, Bethan Copsey, Elin H. Davies, William G. Dixon, Lisa Fox, Javier González, Jessica Griffiths, Chloe H. L. Hinchliffe, Magdalena A. Kolanko, Dylan McGagh, Aryelly Rodriguez, George Roussos, Karen B. E. So, Louise Stanton, Mark Toshner, Frances Varian, Paula R. Williamson, Belay B. Yimer, Sofía S. Villar
Publikováno v:
Trials, Vol 25, Iss 1, Pp 1-12 (2024)
Abstract Background Digital technologies, such as wearable devices and smartphone applications (apps), can enable the decentralisation of clinical trials by measuring endpoints in people’s chosen locations rather than in traditional clinical settin
Externí odkaz:
https://doaj.org/article/cf6a5310e55e4b4fa7371bfea9434463
Publikováno v:
Frontiers in Epidemiology, Vol 3 (2023)
Epidemiological studies often have missing data, which are commonly handled by multiple imputation (MI). In MI, in addition to those required for the substantive analysis, imputation models often include other variables (“auxiliary variables”). A
Externí odkaz:
https://doaj.org/article/8acbd2af222340fe8fead731a45116e5
Autor:
Brennan C. Kahan, Tim P. Morris, Ian R. White, Conor D. Tweed, Suzie Cro, Darren Dahly, Tra My Pham, Hanif Esmail, Abdel Babiker, James R. Carpenter
Publikováno v:
BMC Medicine, Vol 18, Iss 1, Pp 1-8 (2020)
Abstract When designing a clinical trial, explicitly defining the treatment estimands of interest (that which is to be estimated) can help to clarify trial objectives and ensure the questions being addressed by the trial are clinically meaningful. Th
Externí odkaz:
https://doaj.org/article/e989979a7315477483dd2291e0106e75
Publikováno v:
BMC Medical Research Methodology, Vol 20, Iss 1, Pp 1-12 (2020)
Abstract Background The coronavirus pandemic (Covid-19) presents a variety of challenges for ongoing clinical trials, including an inevitably higher rate of missing outcome data, with new and non-standard reasons for missingness. International drug t
Externí odkaz:
https://doaj.org/article/632b606299ba4ffc873f984e3a2d7324
Autor:
Alexina J. Mason, Richard D. Grieve, Alvin Richards-Belle, Paul R. Mouncey, David A. Harrison, James R. Carpenter
Publikováno v:
BMC Medical Research Methodology, Vol 20, Iss 1, Pp 1-12 (2020)
Abstract Background Missing data are an inevitable challenge in Randomised Controlled Trials (RCTs), particularly those with Patient Reported Outcome Measures. Methodological guidance suggests that to avoid incorrect conclusions, studies should under
Externí odkaz:
https://doaj.org/article/9619989e72c24fa7af6bb9a2acd64f77
Autor:
McEwen Khundi, James R. Carpenter, Elizabeth L. Corbett, Helena R. A. Feasey, Rebecca Nzawa Soko, Marriott Nliwasa, Hussein Twabi, Lingstone Chiume, Rachael M. Burke, Katherine C. Horton, Peter J. Dodd, Ted Cohen, Peter MacPherson
Publikováno v:
PLoS ONE, Vol 17, Iss 5 (2022)
Local information is needed to guide targeted interventions for respiratory infections such as tuberculosis (TB). Case notification rates (CNRs) are readily available, but systematically underestimate true disease burden in neighbourhoods with high d
Externí odkaz:
https://doaj.org/article/730747f8fbb74897922611d2bfdfe183
Publikováno v:
Journal of Statistical Software, Vol 45, Iss 5 (2011)
Multiple imputation is becoming increasingly established as the leading practical approach to modelling partially observed data, under the assumption that the data are missing at random. However, many medical and social datasets are multilevel, and t
Externí odkaz:
https://doaj.org/article/6588d3e10f3b454ebdc69729ad0fe8cf
Autor:
Caroline Free, Melissa J Palmer, Kimberley Potter, Ona L McCarthy, Lauren Jerome, Sima Berendes, Anasztazia Gubijev, Megan Knight, Zahra Jamal, Farandeep Dhaliwal, James R Carpenter, Tim P Morris, Phil Edwards, Rebecca French, Louis Macgregor, Katy ME Turner, Paula Baraitser, Ford CI Hickson, Kaye Wellings, Ian Roberts, Julia V Bailey, Graham Hart, Susan Michie, Tim Clayton, Karen Devries
Publikováno v:
Public Health Research. 11:1-96
Background The prevalence of genital chlamydia and gonorrhoea is higher in the 16–24 years age group than those in other age group. With users, we developed the theory-based safetxt intervention to reduce sexually transmitted infections. Objectives