Interviewers asked when the "MOST RECENT skin exam" was done and accepted responses given in either a time period or month/year format. Responses given in a time period format were recorded in two variables, SKNXMNO (Time since skin exam: number of units) and SKNXMTP (Time since skin exam: Time period). Responses given in a month/year format were recorded in two variables, SKNXMDMO (Month of most recent skin exam) and SKNXMDYR (Year of most recent skin exam).

The 2000 NHIS Survey Description advises data analysts to use the summary recodes (SKNXMRMO, SKNXMGYR) "rather than the answers to the original sub questions [SKNXMDMO, SKNXMDYR, SKNXMNO, SKNXMTP, SKNXMEYR]" since "the recodes include all respondents who were eligible for the test, while the raw answers applied only to the subset of respondents who gave the time in a particular format."

For more information, please see SKNCANX.