Assertion: diver's certification | /r/RelatedTo | lower risk
Facets:
Source sentences:
text: The use of dry suits and nitrox breathing gas, greater frequency of diving in the previous year, greater age, and more years since certification were associated with lower risk, possibly as indicators of more extensive training and experience.
text: Nitrox and drysuit use, greater frequency of diving in the past year, increasing age, and years since certification were associated with lower risk, possibly as indicators of more extensive training and experience.