Related Experiment Video
Updated: Jul 11, 2026

07:46
Setting Limits on Supersymmetry Using Simplified Models
Published on: November 16, 2013
Hazards, Causality, and Practical Relevance of Collider Effects - Comment on Beyersmann et al. "Hazards Constitute
Ralf Bender1,2, Lars Beckmann1
1Department of Medical Biometry, Institute for Quality and Efficiency in Health Care (IQWiG), Cologne, Germany.
Biometrical Journal. Biometrische Zeitschrift
|September 8, 2025
Summary
The hazard ratio, crucial for time-to-event analysis, offers a valid causal interpretation at the population level. Real-world randomized trials typically avoid theoretical issues related to heterogeneity.
Area of Science:
- Biostatistics
- Epidemiology
- Survival Analysis
Background:
- Hazards are fundamental in time-to-event data analysis.
- The interpretation of hazard ratios depends on viewing the hazard function over time.
Purpose of the Study:
- To highlight the causal interpretability of hazard ratios as population-level estimands.
- To discuss the practical avoidance of theoretical issues like strong heterogeneity in randomized controlled trials.
Main Methods:
- Conceptual analysis of hazard functions and hazard ratios.
- Review of empirical evidence from randomized controlled trials.
Main Results:
- The hazard ratio serves as a valid population-level causal estimand.
- Theoretical problems arising from heterogeneity are generally not observed in practice.
Conclusions:
- The hazard ratio is a robust measure with causal validity for population-level inference.
- Randomized controlled trials effectively manage potential confounding factors, ensuring reliable hazard ratio interpretation.
Related Concept Videos
The Availability Heuristic
A heuristic is a general problem-solving framework (Tversky & Kahneman, 1974). You can think of these as mental shortcuts that are used to solve problems. Different types of heuristics are used in different types of situations, and the impulse to use a heuristic occurs when one of five conditions is met (Pratkanis, 1989):
Criteria for Causality: Bradford Hill Criteria - II
The Bradford Hill criteria serve as guidelines for establishing causative links in epidemiological research. Beyond Strength, Consistency, Specificity, and Temporality, key criteria also include Biological Gradient, Plausibility, Coherence, Experiment, and Analogy. These principles assist scientists in assessing the likelihood of causation in complex biological contexts. Below is a summary of these concepts:
Causality in Epidemiology
Causality or causation is a fundamental concept in epidemiology, vital for understanding the relationships between various factors and health outcomes. Despite its importance, there's no single, universally accepted definition of causality within the discipline. Drawing from a systematic review, causality in epidemiology encompasses several definitions, including production, necessary and sufficient, sufficient-component, counterfactual, and probabilistic models. Each has its strengths and...
Criteria for Causality: Bradford Hill Criteria - I
The Bradford Hill criteria are a group of principles that provide a framework to determine a causal relationship between a specific factor and a disease. There are nine criteria that are pivotal in assessing causality in epidemiological studies. Here's a closer look at Strength, Consistency, Specificity, and Temporality criteria with definitions and examples:
Hazard Rate
The hazard rate, also known as the hazard function or failure rate, is a statistical measure used to describe the instantaneous rate at which an event occurs, given that the event has not yet happened. From a probabilistic perspective, it represents the likelihood that a subject will experience the event in a very small time interval, conditional on surviving up to the beginning of that interval. In terms of frequency, the hazard rate can be viewed as the ratio of the number of events to the...
Hazard Ratio
The hazard ratio (HR) is a widely used measure in clinical trials to compare the risk of events, such as death or disease recurrence, between two groups over time. It reflects the ratio of hazard rates—the instantaneous risk of the event occurring—between a treatment group and a control group. This measure provides valuable insights into the relative effectiveness of a treatment by assessing how the risk of an event differs between the two groups.
For example, in a clinical trial evaluating a...
For example, in a clinical trial evaluating a...

