Background: This research investigates why a beneficial treatment effect reported at the first interim analysis (IA) may diminish at a subsequent analysis (SA). We examined three challenges in interpreting treatment effects from randomized clinical trials (RCTs) after the first positive IA: overestimation bias; non-proportional hazards; and heterogeneity in recruitment. We investigate how a penalized estimation method can address overestimation bias, and discuss additional factors to consider when interpreting positive IA results.
Methods: We identified oncology RCTs reporting positive results at the initial IA and a SA for event-free (EFS) and overall survival (OS). We modeled: (1) the hazard ratio at IA (HR) versus its timing as measured by the information fraction (IF; i.e., events at IA versus total events sought); and (2), the ratio of HR to HR (rHR) versus the IF. This was repeated for HR adjusted for overestimation bias. Examples of the other two challenges were sought.
Results: Amongst 71 RCTs, HR were positively associated with the IF (slope: EFS 0.83, 95 % CI 0.44-1.22; OS 0.25, 95 % CI 0.10-0.41). HR tended to exaggerate HR, and more so the lower the IF (slope rHR versus IF: EFS 0.10, 95 % CI - 0.22 to 0.42; OS 0.26, 95 % CI 0.07-0.46). Adjusted HR did not exaggerate HR (slope rHR versus IF: EFS - 0.14, 95 % CI - 0.67 to 0.39; OS 0.02, 95 % CI - 0.26 to 0.30). Examples of two other challenges are shown.
Conclusion: Overestimation bias, non-proportional hazards, and heterogeneity in recruitment and other important treatments should be considered when communicating estimates of treatment effects from positive IAs.
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http://dx.doi.org/10.1016/j.ejca.2024.114230 | DOI Listing |
EJNMMI Res
January 2025
Department of Nuclear Medicine, University Hospital of Cologne, Kerpener Straße 62, 50937, Cologne, Germany.
Background: In clinical practice, several radiopharmaceuticals are used for PSMA-PET imaging, each with distinct biodistribution patterns. This may impact treatment decisions and outcomes, as eligibility for PSMA-directed radioligand therapy is usually assessed by comparing tumoral uptake to normal liver uptake as a reference. In this study, we aimed to compare tracer uptake intraindividually in various reference regions including liver, parotid gland and spleen as well as the respective tumor-to-background ratios (TBR) of different F-labeled PSMA ligands to today's standard radiopharmaceutical Ga-PSMA-11 in a series of patients with biochemical recurrence of prostate cancer who underwent a dual PSMA-PET examination as part of an individualized diagnostic approach.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
Indian Institute of Technology-Delhi (IIT Delhi), Hauz Khas, New Delhi 110016, India.
Observation-based verification of regional/national methane (CH) emission trends is crucial for transparent monitoring and mitigation strategy planning. Although surface observations track the global and sub-hemispheric emission trends well, their sparse spatial coverage limits our ability to assess regional trends. Dense satellite observations complement surface observations, offering a valuable means to validate emission trends, especially in regions where emissions changes are substantial but debated.
View Article and Find Full Text PDFObjective: Obesity is a disease with severe health impacts on individuals and economic impacts on society, yet healthcare practitioners (HCPs) and policy makers often fail to address it. This survey was conducted to examine current global obesity care and perceptions influencing care delivery among HCPs and healthcare decision makers (HC DMs).
Methods: A survey with a cross-sectional design was conducted among 1200 HCPs (primary care providers, endocrinologists, cardiologists, and nurses) and 414 HC DMs from eight countries across five continents.
Ecol Evol
January 2025
CEFE Univ Montpellier, CNRS, EPHE, IRD Montpellier France.
Species' future distributions are commonly predicted using models that link the likelihood of occurrence of individuals to the environment. Although animals' movements are influenced by physical and non-physical landscapes, for example related to individual experiences such as space familiarity or previous encounters with conspecifics, species distribution models developed from observations of unknown individuals cannot integrate these latter variables, turning them into 'invisible landscapes'. In this theoretical study, we address how overlooking 'invisible landscapes' impacts the estimation of habitat selection and thereby the projection of future distributions.
View Article and Find Full Text PDFEduc Psychol Meas
January 2025
Department of Educational Psychology, NEAG School of Education, University of Connecticut, Storrs, USA.
In computerized adaptive testing (CAT), examinees see items targeted to their ability level. Postoperational data have a high degree of missing information relative to designs where everyone answers all questions. Item responses are observed over a restricted range of abilities, reducing item-total score correlations.
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