Episode 64 focuses on lagging indicators—the traditional, backward‑looking safety metrics organizations rely on—and explains why they are useful but deeply limited. Dr. Ayers emphasizes that lagging indicators tell you how many people got hurt, not how well your safety system is working.
Lagging indicators measure events that have already happened, such as:
Recordable injuries
Lost‑time cases
DART rate
Workers’ compensation claims
Severity rates
Property damage incidents
They are outcome metrics, not predictors.
Dr. Ayers highlights several weaknesses:
They only measure failure, not success.
They provide no insight into the health of the safety system.
They are influenced by luck, not just performance.
They can be manipulated through reporting pressure.
They encourage organizations to focus on injury counting, not risk reduction.
A company with low injuries may simply be lucky, not safe.
Lagging metrics often create false confidence:
A “good month” may simply mean no one got hurt—not that hazards were controlled.
A “bad month” may reflect a single event, not a systemic failure.
Injury rates don’t show whether controls are effective.
They don’t reveal near misses, exposures, or unsafe conditions.
Leaders who rely solely on lagging indicators are flying blind.
Dr. Ayers uses relatable examples:
A site with zero injuries but dozens of unreported near misses.
A team that hides incidents because they fear discipline.
A department with a low injury rate simply because the work is low‑risk.
A spike in injuries that reveals a deeper operational change no one tracked.
These examples show why lagging indicators must be interpreted cautiously.
Despite their limitations, lagging indicators still have value:
They help identify patterns over long periods.
They are useful for regulatory reporting.
They can highlight severity trends.
They provide a baseline for improvement.
They help communicate risk to executives who expect traditional metrics.
The key is using them as one part of a broader measurement system.
To use lagging indicators effectively, leaders should:
Avoid treating injury rates as the primary measure of safety.
Pair lagging indicators with leading indicators (Episode 63).
Focus on risk, not just outcomes.
Encourage honest reporting by removing fear and blame.
Use lagging data to ask better questions, not to assign blame.
The episode’s message is clear: Lagging indicators tell you where you’ve been, not where you’re going.
