We examined long-term treatment-effect patterns relevant to treatment effect waning (TEW) modeling in oncology health technology assessment (HTA), compared the dispersion and update stability of hazard ratios (HRs) and restricted mean survival time ratios (RMSTRs), and developed prediction models to support extrapolation model selection and TEW modeling.

Using the FDA Hematology/Oncology Approvals Database, we identified phase II/III randomized controlled trials (2006-2025) with updates. We included overall survival (OS) and other time-to-event end points (non-OS). We conducted 2/3/4/5-year landmark analyses to estimate post-landmark HRs and RMSTRs, summarized by event-weighted medians and dispersion (coefficient of quartile relative dispersion, CQR). Update-related change was quantified using updated-to-initial ratios. We predicted longer-term RMSTR using elastic-net regression with nested cross-validation and split-conformal 90 percent prediction intervals.

We analyzed 168 trials (270 contrasts; 150 OS, 120 non-OS). Across landmark analyses at 2, 3, 4, and 5 years, RMSTR was consistently less dispersed than HR for both OS and non-OS end points, while post-landmark HRs generally remained < 1. Update ratios were more stable for RMSTR than HR. Initial and updated RMSTR were strongly correlated (OS r = .87; non-OS r = .82). Parsimonious regularized models accurately predicted updated RMSTR, with conformal prediction intervals achieving 91 percent and 96 percent coverage for OS and non-OS.

Reliance on current HR-based TEW modeling practices alone may be insufficient to fully characterize long-term treatment-effect uncertainty. RMSTR was consistently less dispersed than HR and predictable from early trial data, providing an anchor for extrapolation model selection and TEW uncertainty analysis in oncology economic evaluations.

There have been few studies investigating the association between food security and breast-feeding duration and none have been conducted among Canadian Inuit, a population disproportionately burdened with food insecurity. We evaluated the association between household food security and breast-feeding duration in Canadian Inuit children.

Data were obtained from the Nunavut Inuit Child Health Survey, a population-based cross-sectional survey.

The Canadian Territory of Nunavut in 2007 and 2008.

Caregivers of Inuit children aged 3–5 years. Participating children were randomly sampled from community medical centre lists.

Out of 215 children, 147 lived in food-insecure households (68·4 %). Using restricted mean survival time models, we estimated that children in food-secure households were breast-fed for 16·8 (95 % CI 12·5, 21·2) months and children in food-insecure households were breast-fed for 21·4 (95 % CI 17·9, 24·8) months. In models adjusting for social class, traditional knowledge and child health, household food security was not associated with breast-feeding duration (hazard ratio=0·82, 95 % CI 0·58, 1·14).

Our research does not support the hypothesis that children living in food-insecure households were breast-fed for a longer duration than children living in food-secure households. However, we found that more than 50 % of mothers in food-insecure households continued breast-feeding well beyond 1 year. Many mothers in food-secure households also continued to breast-feed beyond 1 year. Given the high prevalence of food insecurity in Inuit communities, we need to ensure infants and their caregivers are being adequately nourished to support growth and breast-feeding, respectively.