If the analysis runs for 30 seconds or more before the error message displays, then the system may have timed out. In this case, select variables with fewer categories and try running the logistic regression again.
If the error message displays immediately, then verify that the independent variables all have two or more categories and update the variables appropriately.
NOTE: The logistic regression feature is currently considered beta software, so any issues will be resolved in a future release.
Additional information about variables is located in the survey's codebook.
To access the PDAS codebooks, perform the following:
To access the RDAS codebooks, perform the following:
Click the Home icon in the upper-left of the toolbar. The Home page will display with the list of surveys.
Click the SAMHDA logo in the upper-left of the window. The SAMHDA website will display in a separate tab.
NSDUH results from RDAS may differ from the results produced by PDAS and from other published sources. This is due to differences in estimation methodology, rounding of results, and techniques used to protect the confidentiality of respondents.
For PDAS, to protect the confidentiality of respondents, only a subsample of the original sample is used, and data that could be used to identify individuals have been excluded, encrypted, or collapsed. Previously published estimates may not be exactly reproducible due to the disclosure protection procedures that were implemented.
For RDAS, certain geographic identifiers (like State) are available, but analyses are limited to a minimum of two survey years combined, and results are suppressed if they may present possible disclosure risks. In addition, the NSDUH study State-level results view is based on a separate dataset that is computed using a Small Area Estimation (SAE) model, whereas the RDAS results are based on direct estimation.
We strongly recommend you review the study’s codebook when interpreting results. To access the RDAS codebooks, select Data > NSDUH RDAS Codebooks from the SAMHDA main site's menu bar. To access the PDAS codebooks, select Data > Browse Series > NSDUH from the SAMHDA main site's menu bar and drill down to the appropriate study.
Because RDAS allows you to create crosstabs with more granularity than PDAS allows, it poses a greater risk of confidentiality disclosure. RDAS has safeguards to ensure the confidentiality of survey respondents, including suppressing results that could be used to deduce a respondent’s identity.
If you create a crosstab with a variable combination that may violate a disclosure rule, you will receive a message stating “The results from your request could not be provided due to disclosure limitations to protect respondent information. Please try other variables and/or different filtering options.”
If you receive this message, reconsider the analysis to ensure you’re only viewing data important to you. Use the filtering feature, change the variables, or recode the variables to remove the unimportant data and run the crosstab again.