Acceptable Risk of Sudden Incapacitation Among Safety Critical Transportation Workers: A Comprehensive Synthesis.

Objective: Identify a risk threshold for sudden incapacitation for safety critical positions in transportation industries supporting medical fitness for duty standards.

Methods: Systematic literature searches were performed examining acceptable risk criteria for medically related incapacitation using PubMed Central and Google Scholar databases. Websites for professional societies and national and international governmental agencies were also accessed. Article abstracts were reviewed and exhaustive searches were performed.

Results: International regulatory bodies have adopted definitions of acceptable risk typically with a threshold of 1% to 2% absolute risk of sudden incapacitation per annum. Several "risk-of-harm" models have been proposed that incorporate factors modulating an absolute risk constant derived from epidemiological studies.

Conclusion: A 1% absolute annual risk of sudden incapacitation should be adopted as the threshold for determining medical fitness for duty among employees in safety critical positions in transportation industries.