National Health and Nutrition Examination Survey

The Dermatology questionnaire section (variable name prefix DEQ) provides personal interview data on sun exposure and sun protective behavior.

The target group for this questionnaire section is participants aged 20-59 years.

The Dermatology questionnaire was asked, in the home, by trained interviewers using the Computer-Assisted Personal Interviewing (CAPI) system.

The CAPI system is programmed with built-in consistency checks to reduce data entry errors. CAPI also uses online help screens to assist interviewers in defining key terms used in the questionnaire.

Frequency counts were verified during the preparation of the file.

Responses to questions on time spent outside on work or school days (DEQ120) and on days not at work or at school (DEQ125) were collected in either hours or minutes. For data release purposes all responses were converted to minutes. If participants indicated that they did not spend any time outdoors then their values for these questions were set to zero. The corresponding description in the codebook is “no time spent outdoors”. Values of 1-14 minutes were grouped into one category. The code “3333” was set for participants who reported “does not work or go to school” to DEQ120 or “at work or at school 9 to 5 seven days a week” to DEQ125. These variables were then renamed DED120 and DED125 for release, respectively.

Responses to question DEQ038Q, “How many times in the past year have you had a sunburn?” with values of 20 or more combined into one category.

Analysts should be aware that some questions may have very few responses for. Even with two years of data collection, there may not be sufficient sample size for such variables to be analytically useful. In these cases, it may be necessary to combine more than two years of data to conduct analysis. The dermatology questionnaire has been in NHANES since the survey became continuous in 1999. The questions asked in a given 2-year cycle were sometimes modified to focus on different dermatologic topics. In 2007-08 the dermatology section was modified to focus more on sun exposure and sun protective behavior, etc. The 2011-12 dermatology section is identical to that used in 2009-10. 

Most, but not all dermatology data is available publically. Data collection for the 2007-08 dermatology questionnaire did not start at the beginning of the year 2007. Therefore, due to sample size and other disclosure concerns, 2007-08 data for this component are not available publically. It is, however, available as a limited access file through the NCHS Research Data Center (RDC). Researchers interested in using dermatology data from 2007-08 should refer to the RDC website for more information. 

Although dermatology data were collected as part of the household questionnaire, if they are merged with the MEC exam data, exam sample weights should be used for the analyses. Please refer to the NHANES Analytic Guidelines and the on-line NHANES Tutorial for further details on the use of sample weights and other analytic issues. Both of these are available on the NHANES website.