Format

Send to

Choose Destination
Ann Oncol. 2018 Oct 18. doi: 10.1093/annonc/mdy462. [Epub ahead of print]

Interpretation of Time-to-event Outcomes in Randomized Trials: an online randomized experiment.

Author information

1
Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA.
2
Division of General Pediatrics, Department of Medicine, Boston Children's Hospital, Boston, Massachusetts.
3
Boston Medical Center, Department of Emergency Medicine, Boston, Massachusetts.
4
Section of General Internal Medicine, Department of Medicine, Boston University School of Medicine, Boston, Massachusetts.
5
Program On Regulation, Therapeutics, And Law (PORTAL), Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School.
6
National Heart, Lung, and Blood Institute's and Boston University's Framingham Heart Study, Framingham, MA.
7
Department of Epidemiology, Boston University School of Medicine, Boston, MA, USA.

Abstract

Background:

Multiple features in the presentation of randomized controlled trial (RCT) results are known to influence comprehension and interpretation. We aimed to compare interpretation of cancer RCTs with time-to-event outcomes when the reported treatment effect measure is the hazard ratio (HR), difference in restricted mean survival times (RMSTD), or both (HR+RMSTD). We also assessed the prevalence of misinterpretation of the HR.

Patients and methods:

We performed a randomized experiment. We selected 15 cancer RCTs with statistically significant treatment effects for the primary outcome. We masked each abstract and created 3 versions reporting either the HR, RMSTD, or HR+RMSTD. We randomized corresponding authors of RCTs and medical residents and fellows to one of 15 abstracts and one of 3 versions. We asked how beneficial the experimental treatment was (0 to 10 Likert scale). All participants answered a multiple-choice question about interpretation of the HR. Participants were unaware of the study purpose.

Results:

We randomly allocated 160 participants to evaluate an abstract reporting the HR, 154 to the RMSTD, and 155 to both HR+RMSTD. The mean Likert score was statistically significantly lower in the RMSTD group as compared with the HR group (mean difference -0.8, 95% confidence interval, -1.3 to -0.4, pā€‰<ā€‰0.01) and as compared with the HR+RMSTD group (difference -0.6, -1.1 to -0.1, pā€‰=ā€‰0.05). In all, 47.2% (42.7% to 51.8%) of participants misinterpreted the HR, with 40% equating it with a reduction in absolute risk.

Conclusion:

Misinterpretation of the HR is common. Participants judged experimental treatments to be less beneficial when presented with RMSTD as compared with HR. We recommend that authors present RMST-based measures alongside the HR in reports of RCT results.

PMID:
30335127
DOI:
10.1093/annonc/mdy462

Supplemental Content

Full text links

Icon for Silverchair Information Systems
Loading ...
Support Center