Objectives: Survival extrapolation of trial outcomes is required for health economic evaluation. Generally, all-cause mortality (ACM) is modeled using standard parametric distributions, often without distinguishing disease-specific/excess mortality and general population background mortality (GPM). Recent National Institute for Health and Care Excellence guidance (Technical Support Document 21) recommends adding GPM hazards to disease-specific/excess mortality hazards in the log-likelihood function ("internal additive hazards"). This article compares alternative extrapolation approaches with and without GPM adjustment.
Methods: Survival extrapolations using the internal additive hazards approach (1) are compared to no GPM adjustment (2), applying GPM hazards once ACM hazards drop below GPM hazards (3), adding GPM hazards to ACM hazards (4), and proportional hazards for ACM versus GPM hazards (5). The fit, face validity, mean predicted life-years, and corresponding uncertainty measures are assessed for the active versus control arms of immature and mature (30- and 75-month follow-up) multiple myeloma data and mature (64-month follow-up) breast cancer data.
Results: The 5 approaches yielded considerably different outcomes. Incremental mean predicted life-years vary most in the immature multiple myeloma data set. The lognormal distribution (best statistical fit for approaches 1-4) produces survival increments of 3.5 (95% credible interval: 1.4-5.3), 8.5 (3.1-13.0), 3.5 (1.3-5.4), 2.9 (1.1-4.5), and 1.6 (0.4-2.8) years for approaches 1 to 5, respectively. Approach 1 had the highest face validity for all data sets. Uncertainty over parametric distributions was comparable for GPM-adjusted approaches 1, 3, and 4, and much larger for approach 2.
Conclusion: This study highlights the importance of GPM adjustment, and particularly of incorporating GPM hazards in the log-likelihood function of standard parametric distributions.
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http://dx.doi.org/10.1016/j.jval.2021.03.008 | DOI Listing |
Data Brief
December 2024
Instituto de Ciencias de la Atmósfera y Cambio Climático, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico.
Tropical cyclones (TCs) are catastrophic phenomena that constantly threaten populations settled in the tropics. Their direct effects (strong winds, storm surges, and intense precipitation) are confined near the TC center. On the other hand, the indirect effects are due to extreme rainfall events associated with rainbands distant from the TC center.
View Article and Find Full Text PDFEClinicalMedicine
December 2024
Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom.
Background: Elevated body mass index (BMI) ≥25 kg/m is a major preventable cause of cancer. A single BMI measure does not capture the degree and duration of exposure to excess BMI. We investigate associations between adulthood overweight-years, incorporating exposure time to BMI ≥25 kg/m and cancer incidence, and compare this with single BMI.
View Article and Find Full Text PDFMed Decis Making
October 2024
Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden.
Background: In economic evaluations of novel therapies, assessing lifetime effects based on trial data often necessitates survival extrapolation, with the choice of model affecting outcomes. The aim of this study was to assess accuracy and variability between alternative approaches to survival extrapolation.
Methods: Data on HER2-positive breast cancer patients from the Swedish National Breast Cancer Register were used to fit standard parametric distribution (SPD) models and excess hazard (EH) models adjusting the survival projections based on general population mortality (GPM).
Transplantation
September 2024
Center for Surgical and Transplant Applied Research, NYU Langone Health, New York, NY.
Background: HLA-DQ mismatch has been identified as a predictor of de novo donor-specific HLA antibody formation and antibody-mediated rejection. There are insufficient data to guide the incorporation of DQ mismatch into organ allocation decisions.
Methods: We used a retrospective longitudinal cohort of adult living donor kidney transplant recipients from 11 centers across the United States for whom high-resolution class II typing was available.
Water Sci Technol
January 2024
Department of Water Resources Engineering, Faculty of Engineering, Kasetsart University, Bangkok, Thailand.
The advancement of data-driven models contributes to the improvement of estimating rainfall-runoff models due to their advantages in terms of data requirements and high performance. However, data-driven models that rely solely on rainfall data have limitations in responding to the impact of soil moisture changes and runoff characteristics. To address these limitations, a method was developed for selecting predictor variables that utilize the accumulation of rainfall at various time intervals to represent soil moisture, the changes in the runoff coefficient, and runoff characteristics.
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