This is the CodeSystem that contains all the codes in NHSN BSI Risk Factors (http://terminology.hl7.org/CodeSystem/NHSNBSIRiskFactors) and NHSN BSI Risk Factors (http://terminology.hl7.org/CodeSystem/NHSNBSIRiskFactors). E.g. what you have to deal with if you get resources containing codes in either of them