Component Description
The diabetes section (prefix DIQ) provides personal interview data on diabetes, prediabetes, use of insulin or oral hypoglycemic medications, and diabetic retinopathy. It also provides self-reported information on awareness of risk factors for diabetes, and medical or personal cares associated with diabetes.
Eligible Sample
All survey participants aged 1 year and older were eligible. The questions asked varied by age and history of diabetes. Please refer to check items in the diabetes questionnaire and corresponding codebook for question specific details about the eligible target group.
Interview Setting and Mode of Administration
These questions were asked, in the home, by trained interviewers using the Computer-Assisted Personal Interviewing (CAPI) system. Hand cards showing response categories were also used for some questions. When necessary, household interviewers read the hand cards to respondents. Persons 16 years of age and older and emancipated minors were interviewed directly. A proxy provided information for survey participants who were under 16 years of age and for individuals who could not answer the questions themselves.
Quality Assurance & Quality Control
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.
Data Processing and Editing
Frequency counts were checked, “skip” patterns were verified, and the reasonableness of question responses was reviewed. Edits were made to some variables to ensure the completeness, consistency, and analytic usefulness of the data. Edits were also made, when necessary, to address data disclosure concerns.
DID040: How old when a doctor first told you that you had diabetes?
All responses of age 80 years and older are coded as ‘80’, to be consistent with the coding for the participant age variable in the demographics file. Also, the onset of diabetes at age less than 1 year was coded as 666.
DID060: For how long have you been taking insulin?
Taking insulin less than 1 month was coded as 666.
DID250: How many times have you seen doctor in the past 12 months?
The value was coded as 0 for participants who reported “None”.
DID260: How often do you check your blood for glucose or sugar?
This variable was coded as 0 and 666 for participants who reported “Never” and “Unable to do activity (blind)” respectively.
DID341: During the past 12 months, how many times has a doctor checked your feet for any sores or irritations?
The value was coded as 0 for participants who reported “None”.
DID350: How often do you check your feet for sores or irritation?
The value was coded as 0 for participants who reported “None”.
Analytic Notes
In the 2009–2010 data, the core questions for the diabetes component, including doctor diagnosed diabetes, duration of diabetes, insulin use, oral diabetic medication, and diabetic retinopathy are similar to the 2005–2008 and 1999–2004 publicly release data. The remaining questions, including awareness of risk factors for diabetes, and medical or personal cares associated with diabetes are similar to the 2005–2008 publicly release data. However, questions about healthy lifestyle changes to lower the risk for certain diseases, self-reported “A one C” levels, blood pressure readings, and LDL cholesterol numbers are not collected in the 2009-2010 survey.
When combining DIQ data from different survey cycles, please note that there is a possible name change for the same question across release cycles due to the ways of data process and editing. The following cross reference table shows these variable names through the 2009-2010 data.
Variable names across cycles
| Label |
1999–2004 |
2005–2008 |
2009–2010 |
| Age when first told you had diabetes |
DIQ040G |
DID040 |
DID040 |
| Number of years of age |
DIQ040Q |
|
|
| How long taking insulin |
DIQ060G |
DID060 |
DID060 |
| Number of mos/yrs taking insulin |
DIQ060Q |
|
|
| Take diabetic pills to lower blood sugar |
DIQ070 |
DID070 |
DIQ070 |
| Past year times Dr check feet for sore |
|
DID340 |
DID341 |
The analysis of NHANES 2009–2010 diabetes questionnaire data must be conducted using the appropriate survey design variables, sample weights, and the basic demographic variables. Interview weights should only be used if questionnaire data are analyzed by themselves. However if DIQ data are merged with the MEC examination data or laboratory data, the MEC examination weights should be used for analyses. If DIQ data are merged with laboratory sub-sample data, sub-sample weights should be used for 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.