Can rodent longevity studies be both short and powerful?

Area of Science:

• Gerontology
• Comparative Biology
• Biostatistics

Background:

• Rodent models are crucial for studying factors influencing lifespan, including diet, drugs, and genetics.
• Current rodent longevity studies are lengthy, often exceeding 3.5 years, leading to significant time and resource costs.
• Accelerating the acquisition of lifespan data is essential for efficient biomedical research.

Purpose of the Study:

• To evaluate the feasibility of using artificially truncated rodent longevity data.
• To determine if shortened study durations provide comparable mortality effect estimates to full-length studies.
• To assess the power and cost-effectiveness of truncated lifespan experiments.

Main Methods:

• Longevity data from 15 existing rodent studies were collected.
• These datasets were artificially truncated at a 2-year time point.
• Statistical analyses compared point estimates and variances between truncated and full-length study data.

Main Results:

• Point estimates for mortality effects in truncated studies were not significantly different from full-length studies across all assessed experiments.
• The median ratio of variances indicated that truncated studies may require approximately 3.4 times more animals to achieve equivalent statistical power.
• Preliminary cost analyses suggest that while shorter studies incur higher per-animal costs, the overall reduction in time may be advantageous.

Conclusions:

• Artificially truncating rodent longevity studies at 2 years can provide similar mortality effect estimates.
• Truncated studies offer a viable strategy to reduce the time investment in lifespan research.
• Further investigation into power calculations and cost-benefit analyses is warranted for optimizing study design.