Interviewers asked when the "MOST RECENT skin exam" was done and accepted responses given in either a month/year or a time period format. 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). 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).

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.