In controlled trials, "treatment switching" occurs when patients in one treatment group switch to alternative treatments during the trial, and poses challenges to treatment effect evaluation owing to crossover of the treatments groups. In this work, we assume that treatment switching can occur after some disease progression event and view the progression and death events as two semicompeting risks. The proposed model consists of a copula model for the joint distribution of time-to-progression (TTP) and overall survival (OS) up to the earlier of the two events, as well as a conditional hazard model for OS subsequent to progression. The copula model facilitates assessing the marginal distributions of TTP and OS separately from the association between the two events, and, in particular, the treatment effect on OS in the absence of treatment switching. The proposed conditional hazard model for death subsequent to progression allows us to assess the treatment switching (crossover) effect on OS given occurrence of progression and covariates. Semiparametric proportional hazards models are employed in the marginal models for TTP and OS. A nonparametric maximum likelihood procedure is developed for model inference, which is verified through asymptotic theory and simulation studies. The proposed analysis is applied to a lung cancer dataset to illustrate its real utility.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/sim.8585 | DOI Listing |
Adv Ther
January 2025
Department of Hospital Medicine, Ochsner Health System, New Orleans, LA, 70121, USA.
Introduction: Atrial fibrillation (AF), a common heart rhythm abnormality, is linked to a higher risk of stroke. Traditionally, warfarin has been the primary anticoagulation treatment for reducing the stroke risk. The new standard of treatment by direct oral anticoagulants (DOACs) offers greater benefits including improved efficacy and fewer adverse effects with reduced monitoring.
View Article and Find Full Text PDFBMJ Open
January 2025
Centre for Behavioural and Implementation Science Interventions, National University of Singapore Yong Loo Lin School of Medicine, Singapore.
Introduction: Inhalers are critical in asthma treatment, and inappropriate inhaler use leads to poor asthma outcomes. In adults and adolescents, dry powder inhalers (DPIs) are safe and effective alternatives to mainstay pressurised metered dose inhalers and could bridge the asthma care gap while also reducing the environmental burden of asthma care. Despite being licensed for use in ages 5 years old and older, the evidence for clinical effectiveness is less clear for patients between ages 5 and 12 years.
View Article and Find Full Text PDFSci Transl Med
January 2025
Department of Cell Biology and Physiology, Washington University School of Medicine, Saint Louis, MO 63110, USA.
J Clin Gastroenterol
January 2025
Department of Gastroenterology and Hepatology, University Hospitals Leuven, Leuven, Belgium.
Background: Swallowed topical corticosteroids (STC) are an effective first-line therapy for patients with eosinophilic esophagitis (EoE), both for induction and maintenance of remission. All interventional trials with STC used twice-daily dosing regimens. However, in other inflammatory gastrointestinal disorders, corticosteroids are given once daily (OD) with equal outcomes and improved compliance.
View Article and Find Full Text PDFMalawi Med J
January 2025
Department of Health Systems and Policy, School of Global and Public Health, Kamuzu University of Health Sciences, Blantyre, Malawi.
Background: Each year, nearly 400,000 new cases of paediatric hydrocephalus are estimated to occur worldwide, and almost half of these cases are expected to affect children in Africa. At Queen Elizabeth Central Hospital (QECH), an urban tertiary hospital in Blantyre, Malawi, located in south-east Africa, around 200 children received neurosurgical treatment for hydrocephalus in 2023. These children require lifelong follow-up and care, which places significant demands on their caregivers.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!
© LitMetric 2025. All rights reserved.