Multiply your years of shift work by average night shifts per month. The score approximates cumulative circadian disruption.
Exposure score
— pts
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- Risk spectrum with your position marked
- Reference ranges from the original publication
- Shareable link, nothing stored
Scientific references
Why nights accumulate
Each night shift forces the body clock against its light anchored rhythm. The damage is dose dependent, which is why years times intensity predicts metabolic syndrome, diabetes and heart disease in long cohorts of nurses and industrial workers.
Understanding your result
- Under 36 is a low cumulative load
- 36 to 120 is moderate and worth countermeasures
- Above 120 is heavy exposure where mitigation matters most
Countermeasures that work
- Keep the same sleep window even on days off during night blocks
- Bright light at work and dark glasses on the commute home
- Anchor one daily sleep block of at least four hours at a fixed time
Rotation direction
Forward rotating schedules, day then evening then night, are measurably easier on the clock than backward rotation.