What aspect was relevant to an IRB determining that the secondary analysis of a CDC database does not involve human subjects?

The relevance of the data being publicly available and devoid of identifiers is crucial for the Institutional Review Board's (IRB) determination that a secondary analysis does not involve human subjects. When data is publicly available, it means that the information can be accessed by anyone, and thus individual privacy is not at risk. The absence of identifiers—such as names, social security numbers, or other personal details—ensures that individuals cannot be recognized or linked to the data, mitigating privacy concerns. This characteristic separates the dataset from the requirements of human subject protection regulations, which are designed to safeguard individual participants' rights and welfare.

In situations where the IRB assesses whether research involves human subjects, the identification of individuals through the data is a critical factor. If the information cannot be traced back to any individual, then the study can be classified as not involving human subjects, allowing researchers to proceed without the need for full IRB oversight. Thus, this aspect is pivotal in defining the regulatory framework surrounding research ethics regarding human subjects.