The options for incorporating the NHSDA into the NHIS can be summarized by the two extremes (a number of other options could be somewhere in between these two):
1. Select the NHSDA sample from the NHIS sample list frame. NHSDA and NHIS screening and interviewing would be done in separate samples of addresses.
Option 1 would accomplish the smallest cost savings and the least analytic advantage, but would allow the specialized NHSDA sample design and data collection methodologies to be virtually unaffected and most importantly would continue the assurance of anonymity.
2. Conduct the NHSDA as a sample of individuals in NHIS sample households. At the extreme end of this spectrum the NHSDA respondent would be NHIS sample person.
Option 2 would maximize cost savings and provide enhanced analytic capability with the NHSDA and NHIS data being collected on the same respondents, especially if the NHSDA sample person is the same as the NHIS sample person. However, methodological issues such as the importance of respondent anonymity and confidentiality would need to be addressed for this to be viable.
These two options at either end of a range of possibilities incorporate 3 different axes: no personal identifiers (anonymity) vs. personal identifiers (with confidentiality assured); independent screening for respondents vs. use of the NHIS respondents; and the coordination of questionnaire content, independent of survey methods. Coordination of content, especially the non-drug related items, now occurs but could be enhanced in the future, even with the current NHSDA design.
An anonymous survey design could have the following options:
• status quo, current NHSDA plan;
• current NHSDA, but incorporate additional health related data from the NHIS core;
• current NHSDA, but use of NHIS list frame to draw a non-overlapping sample for screening; or
• use same NHIS list for screening for both surveys.
A survey design with personal identifiers (confidentiality assured) could have any of the above options as well as the following options that would involve the direct use of NHIS sampled households:
• NHSDA as a followback to a respondent selected from the sampled NHIS household, and
• NHSDA as an integral part of the NHIS interview process, i.e., NHSDA sample person interviewed at time of selection or return visit.