Background: Information on survey content and survey continuity (e.g., disparity between the survey measures across years) is an important output of major federal surveys because it affects the availability of data and the analytic possibilities. This report presents a summary of the impact of a partial redesign in 2015 of the National Survey on Drug Use and Health (NSDUH) questionnaire and data collection procedures.
Method: The report summarizes the key changes implemented in the 2015 NSDUH data collection and summarizes analysis of unanticipated context effects or identified anticipated breaks in trends.
Results: This report summarizes the effects of the 2015 NSDUH partial redesign and includes an overview of key estimates that are not comparable between the 2015 NSDUH and earlier NSDUH survey years. This report also includes information on questions and topics that are no longer available on the 2015 NSDUH questionnaire and information on topics that are newly available in NSDUH beginning with the 2015 data.
Conclusion: Estimates that are not comparable are assumed to have "broken" trends and to begin new baselines in 2015. The loss of comparability also prevents the pooling of data to produce estimates across multiple years, such as to improve the precision of estimates, when data from 1 or more years are not comparable. This issue especially affects state and substate estimates and certain research studies on specific topics.