a month ago
- Explains the concept of hazard ratios (HR) and why they are commonly used in health and longevity studies, such as HR = 0.90 for eating more fiber or HR = 1.30 for occasional smoking.
- Highlights that converting hazard ratios to changes in life expectancy is complex, as it depends on how baseline mortality risk is distributed over time, using analogies like Russian roulette to illustrate this variability.
- Distinguishes hazard ratios from relative risks (RR), noting that hazard ratios account for time-dependent effects and avoid issues like RR approaching 1.0 in long trials.
- Discusses that interventions often have different hazard ratios at different ages (e.g., chemotherapy works better in younger patients, COVID-19 mortality varies by age), which affects life expectancy changes.