# Restricted Mean Survival Time to Interpret Clinical Trials for Treatment Decision-Making in Older Adults

> **NIH NIH R21** · HEBREW REHABILITATION CENTER FOR AGED · 2020 · $244,633

## Abstract

PROJECT SUMMARY/ABSTRACT
Patient-centered care of older adults with multimorbidity involves shared decision-making based on accurate
communication of evidence. In clinical trials, treatment effect is conventionally summarized in terms of relative
risk reduction using hazard ratios and absolute risk reduction. Despite widespread use, these conventional
measures based on probabilities are not well understood by clinical community and often misleading in treatment
decision-making. We have recently proposed restricted mean survival time (RMST) as a patient-centric outcome
metric that can be intuitively interpreted as the average event-free survival time up to a pre-specified time point.
Treatment effect can be summarized using RMST difference, which means “gain or loss in event-free survival
time due to treatment in a pre-specified period”. Since it is expressed on a time scale that most clinicians and
patients can relate to, it has great potential to facilitate shared decision-making in older adults, which involves
assessment of benefit within a defined time frame, such as the remaining life expectancy. The objective of this
application is to determine the usefulness of RMST in treatment decision-making, using an example of intensive
vs. standard blood pressure lowering strategies in older adults. Our hypothesis is that presenting evidence using
RMST difference, rather than absolute and relative risk reduction, would be more effective in reducing patients'
uncertainty about treatment choice. To test our hypothesis, we will accomplish 2 specific aims to: 1) determine
the benefit of intensive vs. standard blood pressure lowering strategies using RMST difference in older adults
and identify characteristics associated with a greater RMST benefit; and 2) evaluate the effect of evidence com-
munication formats based on RMST difference vs. conventional measures on patients' uncertainty in treatment
decision-making. For Aim 1, we will analyze 2 publicly available datasets from the Action to Control Cardiovas-
cular Risk in Diabetes Trial and Systolic Blood Pressure Intervention Trial to estimate RMST difference. For Aim
2, we will conduct an online survey of 200 community-dwelling older adults and an in-person survey of 100
residents at a local senior housing site. Participants will be randomized to one of the 2 evidence presentation
formats, RMST vs. conventional measures, to assess the effect on reducing uncertainty in decision-making. We
will conduct focus group interviews of 20-30 survey participants to further understand the reasoning and context
behind their choice. Our approach is innovative, because we apply an intuitive and methodologically robust
RMST to analyze and interpret clinical trial data, and rigorously evaluate the acceptability and understanding
from the patient's perspective by adopting quantitative and qualitative design. The impact of this research is
expected to be significant, because our method has great potential to be generalized...

## Key facts

- **NIH application ID:** 9973045
- **Project number:** 5R21AG060227-02
- **Recipient organization:** HEBREW REHABILITATION CENTER FOR AGED
- **Principal Investigator:** Dae Hyun Kim
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $244,633
- **Award type:** 5
- **Project period:** 2019-07-15 → 2022-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9973045

## Citation

> US National Institutes of Health, RePORTER application 9973045, Restricted Mean Survival Time to Interpret Clinical Trials for Treatment Decision-Making in Older Adults (5R21AG060227-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9973045. Licensed CC0.

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